Endophytes are tiny heroes of the garden.
You rarely see them with the naked eye, but most of these tiny organisms work hard to protect our plants.
What are endophytes?
The word ‘endophyte’ literally translates as ‘in the plant’ (‘endo’ = within; ‘phyte’ = plant). Endophytes are tiny organisms that live inside plants, for at least part of their life, without causing disease. In most cases, they provide a benefit to the host. The plant returns the favor by providing the endophytes with carbon [sugar]. Endophytes can be fungal, bacterial, or viral, or they can be other plants. Endophytes are everywhere and they can occur in any place within a plant.
Some endophytes grow between plant cell walls, while others live inside plant cells, and they tend to grow at the same rate as their host. Researchers have learned that plants and their endophytes use chemical signals to communicate with each other. These communications determine which helpful chemicals and what quantities are needed by both sides of the arrangement.
The science behind endophytes is relatively new. Because of this, the definitions are still being sorted out. Some scientists include parasitic and pathogenic organisms as endophytes, while others focus on the beneficial, or mutualistic forms. That’s where I stand, for now. There are several different ways that endophytes help their host plants.
Certain endophytes help plants get the food they need. The rhizobium bacteria that helps legumes fix atmospheric nitrogen is a type of endophyte. Other endophytes break down rock phosphate within the soil, making it absorbable to plant roots. Some scientists categorize mycorrhizae, or root fungi, as a type of endophyte, while others do not. [Isn't it exciting, being on the crest of new scientific research?]
Endophytes have been shown to enhance overall plant growth. They do this by improving a plant’s tolerance of abiotic stresses, such as drought, heat stress, water stress, salinity, and poor soil. When allowed to grow naturally, these mutually beneficial arrangements make both parties stronger. Unfortunately, the use of fungicides interferes with endophyte development. Also, the use of fertilizers reduces a plant’s reliance on its resident endophytes. This is, theoretically, fine, as long as the fungicides and fertilizers continue to be supplied. As soon as these artificial treatments are withdrawn, however, host plants are left with less food and protection.
Commercial agriculture is slowly coming around to the long term benefits associated with these natural arrangements, but you can take advantage of it in your own garden right away by avoiding the use of chemical fertilizers and fungicides.
Did you know that when you inoculate legumes, you are putting endophytes to work for you in the garden? Now you know!
Four-leaf clovers may bring good luck, but some clovers can be a real pain.
The word clover actually refers to three different genera of plants: Trifolium, Medicago, and Melilotus. There are over 300 species of clover and they are found throughout the Northern Hemisphere and occasionally in South America and Africa. Depending on who you ask, clovers can be beneficial ground covers or pesky weeds.
Clovers are also called trefoils because they nearly always have leaves in groups of three. [A four-leafed clover is said to be quatrefoiled.] Clovers are legumes, along with peas, beans, and alfalfa. This means they have a symbiotic relationship with certain Rhizobium bacteria that allows them to fix atmospheric nitrogen and use it to grow. For the most part, clover seeds start to germinate in the fall, and continue until temperatures rise above 60°F. Clovers are classified as annual, sweet, or perennial.
Annual Clovers grow mostly in a prostrate manner from a single taproot. They feature tiny yellow flowers. CA burclover (Medicago polymorpha) and black medic (Medicago lupulina) are turfgrass weeds, while little hop clover, or shamrock clover (Trifolium dubnium) is frequently added to turfgrass mixtures.
Sweetclovers are upright annuals or biennials that grow from 2 to 5 feet tall. White sweet clover (Melilotus alba) and yellow sweetclover (Melilotus officinalis) often turn up in ornamental plantings.
Perennial clovers are often planted on purpose to reduce the need for nitrogen fertilizers. White clover (Trifolium repent) and strawberry clover (Trifolium fragiferum) both have the compound flower heads common to these clovers.
Adding clover as a ground cover or a green manure can mean future plantings will thrive or, as the saying goes, “They will be as happy as a pig in clover.” Of course, bees love clover flowers, so be sure to plant your clover where you are less likely to step on a bee.
If clover is causing problems in your garden or landscape, the best control methods are hand-pulling, hoeing, and mulch. The mulch needs to be 4 to 6 inches deep to block clover. Clover seeds are very rugged, so composting and solarization are generally not effective controls.
If you have bright green clover popping up in a yellow lawn, your soil is probably low on nitrogen.
Did you know that a group of clovers is called a cluff? I didn’t either.
Bermuda buttercup is a sunny yellow flower that appears in the Bay Area each winter and spring.
Originally planted as an ornamental (oops), we now know that this South African invasive weed has the potential to make life quite difficult for our native species.
Also known as sourgrass, Buttercup oxalis, Oxalis cernua, or simply oxalis, this low growing perennial is difficult to control. [The oxalis family is actually quite large and we will discuss that another day.] Close cousin to creeping woodsorrel, oxalis contains relatively high levels of oxalic acid, which is what gives it its sour taste. That is also why they should not be consumed in large quantities by livestock or your backyard chickens
Bermuda buttercup description
Three heart-shaped leaves that resemble clover make Bermuda buttercup (Oxalis pes-caprea) easy to identify. Most Bermuda buttercup plants have a loose rosette of basal leaves and tall stems, usually a foot tall, that feature bright yellow, 5-petalled flowers. You may see brown or purple spots on the leaves. Tiny bulblets form around the stem and more bulbs develop underground. Bermuda buttercup plants produce an average of 10 to 20 bulbs each year. Bermuda buttercup also spreads using runners and through contaminated soil.
Controlling Bermuda buttercup
This weed is very difficult to control, once it takes hold. Pulling the weeds does little to eliminate them, since the bulbs left behind are perfectly capable of starting the whole process over again. While Bermuda buttercup is rarely a problem in lawns, in can quickly become a serious problem in landscapes and home gardens. In the past 10 years, this invasive weed has choked out many native plants.
Homeowners are urged to eradicate this weed, to help prevent its spread into wildlands, where permanent damage may occur. Use the methods below to control Bermuda buttercup on your property, and please educate your neighbors, before it is too late.
You will rarely hear me suggest herbicides, but this is one case where their proper use may be warranted. Always read the label and follow directions exactly. Seriously.
If you really must have pretty yellow flowers in your garden or landscape, please don't let it be Buttercup oxalis.
While these furry, clumsy, easy-going pollinators can sting you, repeatedly even, they generally choose to ignore us. [Unless they get caught in a certain young girl’s unruly long hair. Believe me. I speak from personal experience.]
The name bumblebee, or bumble bee, comes from the characteristic buzz (bumble) of this gentle pollinator. Before it was called bumblebee, it was known as a ‘humblebee’ and before that a version of a ‘clumsily flying buzzing beetle’ or ‘dumbledor’ was used. [I’ll bet you weren’t expecting that one!]
Charles Darwin had this to say about bumblebees in his book, On the Origin of Species (1859):
I have [...] reason to believe that humble-bees are indispensable to the fertilisation of the heartsease (Viola tricolor), for other bees do not visit this flower. From experiments which I have tried, I have found that the visits of bees, if not indispensable, are at least highly beneficial to the fertilisation of our clovers; but humble-bees alone visit the common red clover (Trifolium pratense), as other bees cannot reach the nectar.
Bumblebees really are clumsy fliers. They bump into stems, leaves, and branches quite frequently. Research conducted at the California Academy of Sciences and UC Davis explored how bumblebees are able to withstand the frequent collisions they experience each day. When I say frequent, I mean once a second, on average.
Cousin to honeybees (Apini), orchid bees (Euglossini), and stingless bees (Meliponini), bumblebees (Bombini Bombus) have pollen baskets on their legs, making them all corbiculate. Fossil evidence of the common ancestor to these beneficial insects dates back 100 million years. Bumblebees have been around for 25 to 40 million years, depending on who you ask.
Bumblebees are more commonly found in higher latitudes and higher elevations than other bees. There are even two species found in the Arctic! This may be due to their fur coats, but scientists explain that bumblebees are able to regulate body temperature, using the sun’s radiation and ‘shivering’ to generate heat. Unlike other bees, bumblebee queens are known to incubate their eggs.
Like other insects, bumblebees have a three part body made up of the head, thorax, and abdomen. The head features two compound eyes and three primitive eyes, mouthparts, and antennae. Female bumblebee antennae have 12 joints, while males have 13. The thorax is where the wings, legs, and wing muscles are found. The abdomen contains the digestive and reproductive organs and the stinger.
Bumblebees have two pairs of wings, a fore wing and a rear wing. The wings connect to muscles that are attached to the inside of the plates that make up a bumblebee’s exoskeleton. A waxy substance is secreted from glands and discharged from between the plates. It looks a lot like dandruff. Bees groom the wax into clumps and use it to build honey pots, egg coverings, and as nesting material. Bumblebees do not have ears. We do not know if they can sense sound waves through the air. They do seem to be able to sense vibration through other materials, such as the ground.
Unlike the oblong honey bee, or the shiny black female carpenter bee, your average bumblebee looks round and furry. This is because they are covered with very soft, finely branched bristles, called setae. Bumblebees can usually be differentiated from golden male carpenter bees by the presence of contrasting bands and other markings. This aposematic coloration serves as a warning to would-be predators. Some other insects, such as hoverflies, mimic and are protected by this coloration. This is called Batesian mimicry. Bumblebees come in a variety of sizes, ranging from 1/2 an inch, up to one-and-a-half inches long. [Don’t worry, that big one lives in Chile and is affectionately referred to as a ‘flying mouse’ - okay, maybe not affectionately.]
Bumblebees store fat in their body. This fat is used up during hibernation. Bumblebees do not use the bee dances common to honey bees, but they do exhibit social learning. Youngster bumblebees are frequently bumped off of favored flowers by more mature bees. In a lab experiment, bumblebees were taught to move an object in exchange for a reward. Untrained bees who observed the task-reward process learned it more quickly than those bees who observed the same exchange performed by an inanimate object. In fact, observer bees consistently improve on the methods used initially, implying at least some level of cognition.
Most bumblebee species are social insects. They live in relatively small colonies, led by a queen. Honey bee colonies hold 10 to 60 thousand workers, during peak honey production, while a bumblebee colony may only contain 50 to 1,500 individuals.
Bumblebee nests are first constructed by an over-wintered queen. After collecting pollen and nectar from flowers and finding a suitable nesting site, the young queen will build wax pots to store food, and wax cells to receive her eggs. As the eggs hatch into larvae, the cells are expanded into a lumpy mass of brood cells. Nesting sites can be in or on the ground, or in tussock grasses, depending on the species. Bumblebee nests are a food source for badgers and other insectivores. Bumblebees normally range only a mile or so from the nest.
A queen bumblebee performs a mating flight before retiring to her nest. There, she will ‘decide’ whether or not to use the collected sperm to fertilize each egg she lays. Unfertilized eggs develop into males. Fertilized eggs grow up to be hormonally suppressed worker females or fertile queens. Mature males are forced out of the nest by the females. Males and new queens live independently from the colony, sleeping in flowers or holes in the ground.
Bumblebees feed on nectar, and pollen is collected for the young. Bumblebees lap up nectar with a long, hairy tongue, called a proboscis. The tip of the tongue may also be used as a straw. Because the tongue is so long, bumblebees are able to gather nectar from (and pollinate) deeper flowers than honey bees, which have shorter tongues. When bumblebees fly, the proboscis is often folded under the head. Some bumblebees feed on flowers from above, the way other bees and hummingbirds do, while other ‘rob’ the nectar by cutting a hole in the base of the flower. It is called ‘robbing’ because this behavior avoids pollen transfer. [The metabolic rate of bumblebees is 75% higher than a hummingbird’s.]
Some species of bumblebee leave a scent marker behind on a flower, after it has fed. This marker deters other bumblebees from feeding on that flower, until the marker fades. Once a bumblebee has eaten its fill and collected all of the nectar it can carry, it returns to the nest and deposits its riches in brood cells, for the young, or in wax cells, for storage. Unlike honey bees, which process nectar into honey, bumblebees store it as-is.
Bumblebees as pollinators
Bumblebees are powerful pollinators. As they feed, moving from flower to flower, they collect and deposit pollen. Bumblebees are commonly used in greenhouse tomato production. They are fed sugar water so that they do not need to harvest nectar, and can focus exclusively on pollen.
[Did you know that pollen is left behind at each flower because the act of flying causes the bee to build up a static charge? The plants, being rooted in the ground, are, well, grounded. The electrically charged pollen grains on the bee are attracted to the stigma, which happens to be the best grounded part of a flower, while the flower’s grounded pollen is attracted to the bee’s statically charged body. How bizarre and amazing is that?!!?]
Bumblebees also pollinate plants by a method called buzz pollination, or sonication. They do this by disconnecting their wings from their flight muscles and vibrating their wings at a frequency very close to middle C. The force generated during sonication can reach 30 Gs, which is almost more than a human can tolerate! This vibration causes a flower’s pollen to burst forth. This method is particularly effective on blueberries and members of the nightshade family, such as tomatoes, tomatillos, and eggplant. Sweat bees, carpenter bees, and stingless bees sonicate, but honey bees do not. PBS has an amazing video of buzz pollination.
California bumblebee species
There are over 250 species of bumblebee worldwide and 26 species in California. There used to be 14 native bumblebee species in the Bay Area. Now there are only a handful. This is especially unfortunate when you realize that native bumblebees are responsible for pollinating 42% of all native California flowering plants, according to UC Davis entomologist Robbin Thorp. Currently in the Bay Area, you may see:
These bumblebee species have not been seen in the Bay Area in recent years:
Cuckoo bumblebees, or brood parasitic bees, do not live in colonies. Instead, cuckoo queens will invade a nearby bumblebee nest, kill the queen, and then start laying their own eggs, which end up being cared for by the murdered queen’s workers. [You can tell the difference between a cuckoo bumblebee and a social bumblebee by looking closely at the back leg: nesting female bumblebees have a pollen basket, which is bare and shiny, whereas a cuckoo bee hind leg is covered with hairs. They transport pollen by wedging it between the hairs.]
Like the European honey bee, bumblebee numbers are declining. This is largely due to habitat loss, pesticide use, and the mechanization of agriculture. You can counteract some of these effects by planting flowers that attract and provide for bumblebees.
Bumblebees are attracted to flowers by both sight and smell. They seem to prefer flowers that grow on spikes, such as salvia and lavender. This may also be because these flowers tend to be blue, purple, or white, favorite colors of bumblebees. Bumblebees are also attracted to members of the sunflower family. The most important consideration when planting to attract bumblebees is that the stems are sturdy enough to support these heavy pollinators. Bumblebees can also see a flower’s temperature, as well as its electrical field.
You may very well already have plants that attract bumblebees. If you allow your kale and other cabbage family members to bolt in early spring, bumblebees will take advantage of the blooms, and you will add these plants to your foodscape as seeds are dispersed later in the season. Other popular flowers that attract bumblebees include anise hyssop (Agastache foesniculum), guaras (Guara lindheimeri and other cultivars), bog sage (Salvia uliginosa), Mexican sage (S. mexicana) and many members of the mint family, including basil, thyme, sage, and rosemary. Native plants, such as manzanita, ceanothus, CA buckwheats, penstemons, currants, and gooseberries will also attract and provide for these hard working beneficial insects.
Bumblebees are housing opportunists. They build nests in upturned planter pots, abandoned mouse burrows, and under boards. If you have a square foot of bare, undisturbed soil and the right flowers, you are pretty much guaranteed a visit.
The U.S. Forest Service offers a comprehensive guide to California bumblebees and a nice poster of western bumblebees with dietary notes. You can also learn more about bumblebee conservation from the Xerces Society.
Pine trees, junipers, the mighty redwood are all members of an ancient family, the conifers.
Conifers have been around for 300 million years. They were the dominant plant of the Mesozoic Period, or the Age of Reptiles, and a primary food of many herbivorous dinosaurs.
Adding conifers to a landscape is an excellent way to create year round color. They make excellent anchor plants and they often create food and habitat for wildlife, increasing your garden’s biodiversity.
All conifers are perennial woody plants that get thicker and larger with age. The secondary growth that allows a giant redwood to attain its amazing size all takes place in the cambium layer, just under the bark. Conifers (Pinophyta) are unlike many of our common garden plants, and for several reasons. The most obvious difference is that conifers are gymnosperms, which are cone-bearing seed plants.
Botanically, a cone is called a strobilus. Strobili protect the seeds as they develop. This can take from four months to three years, depending on the species and environmental conditions. Some species of conifer need fire to release their seeds. These cones, in particular, will stay tightly closed for 60 to 80 years, waiting for fire.
Cones can range in size from 1/10 of an inch to two feet in length. There are male cones that produce pollen, and female cones, where pollination occurs. Both types of cones are usually found on each tree. Different species of conifer spread their reproductive cycle out over one, two, or three years.
While some plant families include thousands of species, the conifers boast only 7 or 8 subfamilies (depending on which botanist you ask) and most of us recognize even fewer. There are less than 630 living species of conifer worldwide. These include pine, cedar, redwood, larch, cypress, fir, Douglas-fir, kauri, juniper, hemlock, yew, and spruce. All conifers are in the Pinales order and the Pinaceae family. Botanists break down the subfamilies in this way:
Abietoideae - fir
Cedrus - cedars
Cupressaceae - cypress
Larix - larch
Pseudotsuga - Douglas-fir
Tsuga - hemlock [Not to be confused with poison hemlock]
Piniodeae - pine
Piceoideae - spruce
Taxaceae - yew
Other subfamilies include Araucariaceae and Podocarpaceae, both found in the southern hemisphere, Sciadopityaceae, found in Japan, and Cephalotaxaceae, mostly found in SE Asia.
While there are fewer types of conifers, these trees once covered major portions of North America and they are still the world’s greatest carbon sink. Many conifers are grown commercially for softwood lumber, paper production, and Christmas trees. Stone pines are also grown for their delicious edible pine nuts.
Conifers hold nearly all the records for height (nearly 380 feet tall), girth (over 37 feet across), volume (over 1,400 square feet), and age (4,700 years). While each conifer species is unique, they also share many common characteristics:
Pruning pines is different from pruning other trees and plants. Where most plants will sprout at the bud nearest a cut, pines only have one growing tip per branch. If this growing point is cut off, the branch will die. Pruning conifers is done before the branches actually form. As newly expanding buds, or candles, are seen, they can be allowed to grow, or they can be pinched back. Candles can be pinched back partially or completely. Candles are where the needles emerge. The bud is pinched back just as the needles begin to emerge. Where you pinch will dictate where new growth buds will form.
Looking closely at the needles of a conifer is one of the easiest ways of telling the different species apart. If the needles occur in bunches of two, three, or five, it is most likely a pine. If the needles occur singly, it is probably either a spruce or a fir. If that single needle rolls easily between the palms of your hand, it is spruce. [It actually has four sides, but you probably won’t be able to tell.] If the needle feels flat and does not roll easily, it is a fir.
Conifer pests and diseases
Bark beetles and their larva (roundhead borers) can cause significant damage to members of the pine family. Adelgids, aphids, spider mites, spittlebugs, conifer twig weevils, nematodes, and sawflies can also cause problems. The larva of several moths, including the clearwing, rusty tussock, Douglas fir tussock, spruce budworms, and the Douglas fir pitch moth all feed on conifers. These evergreens are all susceptible to canker diseases, root rot, crown rot, slime flux, and needle casts. Some of these pests can be captured with sticky barriers.
The biggest problems faced by homeowners with conifers are wind, heavy rain, and flooding. Like many other trees, conifers have a shallow root system that spreads out very close to the soil surface. Because these trees carry so much weight above ground, they can tip over. This makes it very important to install potentially large trees far enough away from structures, such as your home, chicken coop, or garage, to prevent serious harm in the case a tree falls.
Did you get a conifer during the last holiday season? If so, check out my handy holiday plant care page!
Few weeds come up as quickly and resiliently as common groundsel.
Also known as old-man-in-the-spring, this European annual weed prefers our cool, wet winter weather, dying off each summer, but it never fails to return each year. In fact, common groundsel is classified as a ruderal species, which means it is one of the first plants to start growing in disturbed soil.
Common groundsel description
Like other members of the sunflower family, common groundsel (Senecio vulgaris) features a sunny yellow flower. Akin to dandelion’s, mature seed heads transform into puffballs that fly on every breeze. The flowers of common groundsel are smaller than those of dandelions, and the green bracts have black tips. The plant has an upright growth, reaching up to 2 feet in height, but usually closer to 16 inches.
Rather than the lion’s tooth leaves seen on dandelion plants, common groundsel features pinnately lobed leaves (with matching loops and curves on either side), and may be toothed near the edges. Leaves are smaller near the top of the plant and may be covered with fine hairs. The leaves are sessile, which means they attach directly to the plant. The stems are hollow and the root system is a shallow taproot.
If robbing nearby garden plants of sunlight and nutrients weren’t bad enough, common groundsel is also a carrier of disease pathogens (vector). It can host Cineraria leaf rust (Coleosporium tussilaginis), a fungal disease. It can also carry the fungus that causes black rot, another fungal disease that can affect citrus, chickpeas, cucurbits, such as cucumber or melon, tomatoes, and peas.
A toxic weed
While hailed as a medicinal plant, common groundsel contains chemicals, called pyrrolizidine alkaloids, that can make people and animals ill. Chronic exposure can cause irreparable liver damage. You’d have to eat an awful lot of it, but I avoid feeding it to my chickens, just to be on the safe side.
Controlling common groundsel
Common groundsel is self-pollinating. Each plant can produce 1,700 seeds, and there can be three generations per year. That ends up being a lot of weeds! The best way to control common groundsel is to prevent it from spreading in the first place. This means snatching seed heads any time they are seen and tossing them in the trash. Seedlings are far easier to pull than mature plants, so learn to recognize them and pull them out every time they are seen.
Heavy common groundsel infestations can be slowed or halted with sheet mulching. Follow these steps to successfully sheet mulch an area:
As with all weeds, this is an ongoing battle. Because these plants carry disease, it is better to be vigilant.
Bright, cheery colors, delicate textures, and you can eat them!
Edible flowers have been part of the human diet since, well, since there have been people! Did you know that carnation petals have been used as one of the ingredients in the French liqueur, Chartreuse, since the 17th century?
Before we start, let me first share a story from my early trials with edible flowers. My dear sister decided to marry an Australian sailor and asked me to make her wedding cake. It was a lovely tiered white cake with yellow borders. I decided to add some stunning yellow flowers I saw outside. My sister’s reaction of horror was not what I expected - until she explained that the Angel’s Trumpet flowers I used were extremely poisonous. Needless to say, the flowers and the frosting came off. So…
When in doubt, don’t
Before you go popping random blossoms in your mouth, you need to know that some flowers can make you sick, and others can kill you. If you are even remotely unsure about a plant, do not eat it. Sometimes there is a fine line between edible and inedible. For example, regular garden variety pea flowers and shoots are edible and delicious, while fragrant sweet peas (Lathyrus odoratus) are poisonous. Some varieties of day lilies are edible and others are not. The same is true for phlox and geraniums. Make sure know what you have before tasting it.
Also, chemical sprays and car fume residue can be toxic, too. Chemical pesticides, herbicides, and insecticides should not be used on flowers that will be eaten. Never eat flowers from commercially grown plants, as there is no way to know for sure what has been applied to or used in growing these plants. Now that I have reminded you to be careful, let’s see just how many flowers in your garden are edible!
All herb flowers are edible.
Basil, chives, cilantro, garlic, dill, lavender, marjoram, mint, oregano, rosemary, sage, savory, and thyme flowers can all be used to add an extra depth and a touch of color to many different dishes. You can also eat the flowers of anise hyssop, angelica, bee balm, burnet, chervil, fennel, ginger, and lemon verbena.
There are a surprising number of edible flowers. All members of the viola family, which includes Johnny-jump-ups and pansies, and the dianthus family, or carnation fame, are edible.
Edible fruit tree flowers
The flowers of many fruit and nut trees are also edible. Apple, apricot, peach, pear, and plum blossoms can be used to add color and a delicate complexity to many dishes. When using these flowers, be sure to only use the petals, and not the stamens or pistils. Because they contain low levels of cyanide, apple blossoms should be eaten in moderation. Citrus blossoms are very string and should be used sparingly. Leftovers can be added to floral arrangements, so that you can still enjoy the aroma.
Edible vegetable flowers
Your probably already eat several vegetable flowers: artichoke, broccoli, and cauliflower, for example. While eating the flowers of your vegetable plants reduces your crop yield, it can be a nice way to try something new. There are several different vegetable plants with edible flowers:
Ways to use edible flowers
While it is easy to sprinkle petals into a salad for a splash of color and flavor, there are many other ways to incorporate edible flowers into your diet:
Preparing edible flowers
Edible flowers should be picked just before using and thoroughly rinsed off. This will help remove dust, frass, microorganisms, and any surface chemicals that may have blown in or been applied. Taste the flowers before using them, so that you know what flavor you are adding to your food.
Remove the pistils and stamens from most flowers. The only exceptions are violas and Johnny-jump-ups - in these cases, the other parts add good flavor. If you detect some bitterness in any edible flower, you may need to remove the white base of the petals. This is commonly needed when working with carnations, chrysanthemums, day lilies, and roses.
How many edible flowers do you have in your garden? Tell us in the comments!
Have your new seedlings been chewed off at ground level? It may be darkling beetles.
Darkling beetle is the common name for all 20,000 species within the Tenebrionidae family. Some of the more famous California darklings include Blapstinus, Coelus., and Eleodes..
Darkling beetle identification
Darkling beetles are dull black, blueish-black, or rusty brown, depending on the species. Unlike other beetles, the wings of darkling beetles are fused together. Some species have longitudinal ridges on their wing covers, but most are smooth, without markings of any kind. One exception is the wooly darkling beetle (Eleodes osculans), which is covered with tiny hairs. Darkling beetles can range from 1/8 to 1-1/2 of an inch long. The antennae are well developed and often have knobs at the ends (clubbed).
Darkling beetles are frequently confused with predaceous ground beetles (Carabidae), but ground beetles are shiny and their antennae are more delicate. There are other differences, but you get the idea. Darkling beetle larva look like pale yellow or dark brown wireworms. They are less than 1/3 of an inch long and are often called false wireworms. You may know one particular branch of this family as mealworms (Tenebrio molitor).
Did you know that mealworms can digest styrofoam?
Stanford researcher Craig Criddle discovered that the bacteria found in a mealworm’s gut can transform polystyrene into “carbon dioxide and recyclable organic waste.” How cool is that?!!? (UCANR)
Darkling beetle behavior
These pests tend to walk with their heads down and their abdomens somewhat lifted. Very often, they will stand completely still, in a headstand position, if frightened. While not dangerous, they can squirt you with a nasty smelling secretion from that rear end that does not wash off easily. This behavior is what gives some darkling beetles the name Skunk Beetle or Stink Beetle, not to be mistaken with stinkbugs. For the most part, these pests only come out at night, but you may catch one running across the patio or lawn during daylight hours. Normally, they hide under dirt clods, fallen tree bark, rocks, boards, wood chips, and in other dark places during the day. Often, the only way you know you have a darkling beetle problem is because of the damage they cause.
Darkling beetle damage
In addition to attacking seedlings at ground level, darkling beetles feed on the foliage of many garden plants, such as lettuce, chicory, cabbage, broccoli, and other brassicas, beans, melons, pumpkins, tomatoes, and squash. This feeding can be seen along leaf edges and on the underside of leaves. Darkling beetles also feed on the ‘netting’ (raised areas) of melons, the flowers of most cucurbits and pistachio, and on some fruit crops, such as figs.
Some species of darkling beetle also act as vectors for plant diseases and poultry parasites. Some darklings can also cause structural damage to insulation and wooden buildings. They are also attracted to poultry feed, but my guess is that the chickens make short work of that arrangement, as long as the unavailable feed is stored properly, in a metal container.
Darkling beetle control
Commercial farmers use insecticides to kill these pests. They also use a shallow ditch, filled with water, to block these pests from coming out of the weeds and into the fields. If you are an organic grower, as I am, you will have to use cultural controls. You can minimize darkling beetle damage organically when you:
In 2015, a report published by The Coleopterists Bulletin warned that three non-native darkling beetles have been found in California and Nevada. Each of these species is somehow tied to ant or fire ant populations:
I was unable to find any freely available photos, so you will have to track them down on your own. If you see any of these invasive beetles, please capture them and contact your local County Extension Office.
You may be surprised to learn that some people keep darkling beetles as pets.
Allelopathy is the scientific word for chemical warfare in the plant world.
There is plenty of New Age talk about ‘companion plants helping’ each other, but that is not true. Plants do not choose to help their neighbors. [We’ll get into the discussion about ‘plant intelligence' another day.] The truth is, life is a battle. Even in the garden.
Competition for resources
Most plant roots are constantly competing with neighboring plants for water and mineral nutrients. In the same way, most plants reach for as much sunlight as they can get, regardless of the needs of neighboring plants. That’s life. Its not a decision; its survival. Weeds compete with your garden plants by growing faster. Some plants use tendrils to climb other plants. And some plants use chemicals against neighboring plants and other organisms.
What is allelopathy?
Allelopathy [al-el-ah-path-ee] is a common way for plants to reduce competition in the immediate vicinity, and to reduce feeding by herbivores. Allelopathic plants actively discharge chemicals through their leaves, bark, and roots, as they decompose, and through other processes. These chemicals can stimulate or inhibit the germination, growth, development, reproduction, and survival of other plants and organisms. Autotoxicity is the flip side of allelopathy. In autotoxicity, plants generate chemicals to inhibit the growth of the same species in the vicinity. The chemicals used in allelopathy always impact other species of plants and organisms. These biochemicals are called allelochemicals.
Allelochemicals can interfere with another plant’s nutrient uptake, photosynthesis, pollen or seed germination, cell division, and even specific enzyme functions. These battles are being fought on the cellular and molecular levels! Because of these effects, allelochemicals are used in commercial agriculture as natural herbicides. For example, the lemon bottlebrush plant (Callistemon citrinus) produces an allelochemical called Leptospermone. Leptospermone is not strong enough on its own to be effective, but a synthetic version, nestorione, is. Nestorione is commonly used to control broadleaf weeds in corn, as well as the crabgrass in your lawn. Allelochemicals are also used as growth regulators, insecticides, and antimicrobial products. One advantage to using allelochemicals is that they tend to not have long term residual effects. Caffeine, and certain flavonoids, tannins, and phenols are all allelopathic chemicals.
Plants grow where their resource needs can be met. Because of this, allelopathy is an important player in species distribution and population density in the world and in your garden. In some cases, allelopathy gives weeds and invasive plants the upper hand. Nutsedge, garlic mustard (Alliaria petiolata), and spotted knapweed (Centaurea maculosa) all use allelopathy to beat out the competition. The allelochemicals used by garlic mustard have been shown to interfere with native tree roots and their mycorrhizal fungi, which help the trees gather mineral nutrients from the soil.
Allelopathy and incompatibility
Since some plants leave behind an allelopathic residue, it is a good idea to be aware of the potential for incompatibility when intercropping (succession planting), mulching, using green manure, planting catch crops, or when rotating crops. For example, decomposing straw has been shown to suppress weed growth, as well as reduce the number of pests and diseases found in an area, because of the allelochemicals contained in the straw. As it decomposes, it also improves soil structure and soil fertility. At the same time, decomposing straw temporarily increases the carbon-to-nitrogen ratio, so you may need to supplement the area with nitrogen.
Catch crops, planted to protect the soil from erosion between major crops, are an excellent way to protect your soil, but they also introduce allelochemicals that may interfere with the next crop. One sorghum-sudangrass hybrid (Sudex), in particular, can kill 50 to 75% mortality of your tomato, broccoli, and lettuce plants!
Many common plants use allelochemicals. Black walnut is the most notorious, but the story isn’t (as is often the case) as simple as it is made out to be. Black walnut (Juglans nigra) produces several allelochemicals which are said to block everything from growing underneath. This is simply untrue. The chemicals involved, and the interactions, are far more complex than that. Onions, beets, squash, melons, carrots, parsnips, beans, yarrow, stonecrops, and corn can all be grown near a black walnut tree without any problems, according to the PennState Extension. At the same time, blackberries, raspberries, blueberries, asparagus, eggplant, peppers, potatoes, and tomatoes do not grow as well when planted near a black walnut tree, according to the University of Illinois Extension.
Allelopathy and agriculture
Most of the research regarding allelopathy focuses on commercial agriculture. It tells us that rice, some Eucalyptus species, and the Tree of heaven (Ailanthus altissima) all use allelochemicals. It also demonstrates that rye mulch significantly reduces broadleaf weed growth, and that growing mung beans in a corn field reduces crop yield, while growing tobacco in the same corn field increases corn production.
Allelopathy in the garden
This is a highly complex issue that cannot be watered down very far before everyone is simply guessing. That being said, I have been able to glean the following useful information for the home gardener:
If you suspect that two plants are incompatible, simply conduct an online search, using both plant names and the word allelopathy. If there is any research available, please let us know in the comments section!
Most of the ‘rules’ associated with allelopathy have been developed with large-scale agriculture in mind. They are diluted by all the other factors occurring in your garden and compost pile, so take it with a grain of salt.
This information is not going to stop me from composting my healthy pea plants, but it will make me more aware of my plant choices, when it comes to cover crops, crop rotation, and catch crop planting.
Ratta-tat-tat-tat-tat-tat. That rapid-fire drilling can only mean one thing: woodpeckers.
What are these birds looking for and can they damage your trees? Let’s find out!
What a headache!
The familiar drumming sound of a woodpecker hammering on a tree (or your house!) can mean they are looking for food, or a mate. They may also be excavating a nesting site. When a woodpecker drums on a tree trunk, or the side of your house, they do so at a rate of 20 to 25 times per second, with a force of 1200 grams. On average, a woodpecker weighs 100 grams. So, imagine banging your head on a wall, 20 times a second, with a force equal to 12 times your body weight! Woodpeckers perform this behavior on a daily basis without knocking themselves out, or causing brain damage. That’s pretty amazing. So amazing, in fact, that woodpeckers are studied extensively for things like shock-absorbers. It ends up that a woodpecker’s head can withstand a deceleration of 600 to 1500 grams, while the human brain can only handle 300. So, let’s see what all that drumming and drilling is about.
Both genders drill holes in wood to reach burrowing insects (pests) and to stimulate the flow of sap from the cambium layer. Woodpeckers eat the sap, and they use it to attract and trap insects, which they also eat. Anna’s hummingbirds and ruby-crowned kinglets also take advantage of this buffet created by woodpeckers. [They sure as heck can’t drill those holes for themselves!]. Woodpeckers also eat fruit, nuts, and berries, but they are, generally, not a significant problem in this way.
Male woodpeckers use the drilling to demonstrate their prowess to local females and to claim territory. The better the resonance, the better the performance, which is why many homes are chosen over nearby trees. They will even use metal rain gutters and downspouts during the peak of the breeding season. Females also enjoy drumming, both for food and to alert males to their presence.
Classically, woodpeckers are black and white, and males feature some red, usually on the head. The beak is sturdy and sharply pointed. You may not ever see it, but woodpeckers have a very long tongue, which they use to pull larva and other insects out of crevices. If you look closely, most woodpeckers also feature short legs and two, backward-facing toes with sharp claws. These 'zygodactyl' toes, combined with a stiff tail, help hold the bird in position while drilling.
The name ‘woodpecker’ actually refers to woodpeckers, sapsuckers, and flickers. These birds are all in the same family (Picidae). California is home to eleven woodpecker species, four sapsuckers, and two flicker:.
Acorn woodpeckers are particularly destructive to homes because they wedge acorns into all the holes they create. A single acorn woodpecker may collect and store thousands of acorns between wooden shakes and shingles in a single season!
Sapsuckers are a shy group. If you walk by, they will scuttle to the other side of a tree trunk, trying to stay hidden. These birds make a mewing sound. They drill rows of round or squarish holes in certain trees. All sapsuckers have a white rump, white wing patches, and there is always a degree of yellow on the belly. There are four different sapsuckers here in California:
These once common birds are losing ground to introduced starlings, which aggressively compete for nesting sites. Flickers love to eat ants and na be seen hopping up and down tree trunks in search of these treats. There are two species of flickers in California:
Preventing woodpecker damage
The problem with woodpecker feeding is that the loss of sap may weaken a tree, and it creates a point of entry for other pests and pathogens. Unless the feeding is extensive, however, most trees can handle it without much of a problem. If the feeding becomes a problem, woodpeckers can be blocked by panels of lightweight sheet metal or 1/4-inch hardware cloth wrapped around the favored feeding areas.
Research has shown that repellents and frightening devices are not effective. Urban myth claims that hanging nesting boxes and providing suet is one way to eliminate the risk of woodpecker damage. Research has shown that these provisions do not consistently reduce the problem and may actually attract even more woodpeckers into an area.
Benefits of woodpeckers
Before we try to ban these beautiful birds from our gardens, keep in mind that the nesting holes they create are often used by other native, cavity-nesting birds. Woodpeckers also remove a significant number of potentially damaging insects from our fruit and nut trees. Finally, we do not yet fully understand the value of biodiversity.
While not a native of California, this magnificent bird of the Mississippi Delta deserves mention. The Ivory-billed woodpecker (Campephilus principalis) was/is believed to be extinct. The last confirmed sighting occurred in 1944. In 2005, video emerged that may have been of an Ivory-billed specimen. There is some debate about this, as it could also have been a slightly smaller, common Pileated woodpecker. The Cuban ivory-billed woodpecker has been considered extinct since 1987. Ivory-billed woodpeckers are/were very large. At 20” long, with a 30” wingspan, they must have been hard to miss. They were able to live 20 to 30 years, but Native Americans decided that the Ivory-billed woodpecker’s massive bone beak was a prized decoration, so the killing began. If you are ever lucky enough to hear the tell-tale double-knock of an Ivory-billed woodpecker, record it, photograph it, and contact the Audubon Society right away!
Did you know that a group of woodpeckers can be called a ‘gatling’ or a ‘drumming’ or a ‘descent’?
I didn’t either.
Do you have any woodpeckers visiting your garden? Tell us which ones in the comments!
Leaves come in a variety of shapes. Having a firm grasp of the vocabulary associated with leaf shapes can help you to identify and talk about plants more effectively.
This is a HUGE subject, so, grab yourself a beverage and get comfortable.
When describing leaf shape, some terms refer to the entire leaf, while others refer to specific parts of the leaf, such as the edge, tip, or base. Nearly all the terms are tied closely to the Latin word forms, so you are in luck if foreign language comes easily (or if you happen to already know Latin). Personally, I am not gifted in that particular area. Luckily for all of us, Latin is a pretty reliable language, when it comes to putting pieces of words together to make new words.
Don’t let all these new words scare you off, and don't expect to be able to remember everything. You can always return to this page, or use a field guide, when describing leaf shapes or identifying unknown plants. The important thing is to become familiar with the different ways that leaves are described and categorized.
Leaf and leaflet silhouettes
Leaves are first identified by their overall shape. They can be round, triangular, oval, rectangular, or diamond-shaped:
Some leaves are shaped like a heart, kidney, fan, arrowhead, or spear:
Some leaves are shaped like a teardrop, while others look more like the silhouette of a violin, a spoon, a sickle, or a hand:
The Latin of lobes
Some leaves have protrusions, called lobes, that can be rounded (like your earlobes) or pointed. Lobes can be arranged pinnately (in pairs) or palmately (like a hand). Lobes can be gently waving lines, they can be sharp incisions, or they can fall somewhere in between. These features are usually described as relative to the midrib line. Depending on the type of lobe a leaf might have, descriptive suffixes are added:
All about the base
The way leaves attach to the rest of the plant can also provide clues for identification.
Here’s a tip
At the other end of the leaf, tip shape can also provide clues for identification. Leaf tips can be:
There is a lot of variation in leaf tips:
Take it from the edge
The edge of a leaf is called its margin. Leaf margins provide an easy classification tool, since this trait stays consistent within a species. At the most basic level, leaf margins are:
If the stem attaches to a leaf near the middle, rather than at an edge, it is peltate. [Nasturtium] If it looks as though the stem passes through the middle of the leaf, it is perfoliate. [Miners lettuce]
I will be adding more images and examples of different leaf shapes in the near future but, for right now, it has stopped raining and hailing and my garden is calling.
How many different leaf shapes can you identify in your garden?
Leaves nearly always appear singularly or paired. There’s nothing unusual about that, but the mathematics behind those arrangements may surprise you.
Take a look at a stem or flower from above. You will almost always see distinct patterns in the way the leaves and stems are organized. These patterns are called phyllotactic spirals. Very often, Fibonacci numbers and the Golden Mean (or Golden Angle) are involved. Fibonacci numbers are a big part of nature and architecture. You can get a simple explanation at the bottom of my post on garden design.
Leaves emerge along a twig or stem at points called nodes. The space between each node is called the internode. Sometimes, in the angled space between the leaf and the stem, called the leaf axil, a bud may appear. The scaly covering on buds is actually made up of modified leaves, called bud scales. Note that only leaf buds have scales; flower buds do not. Where leaves emerge, along a stem, is determined by plant hormones, called auxins.
At the most basic level, leaves emerge from a stem either individually or in pairs. Leaves that take turns up a stem, alternating from one side to the other, are called alternate. Leaves that appear in pairs are called opposite. Leaves growing close to the ground, around an upright stem, whether alternate or opposite, are called basal. Leaves arranged like an upright deck of cards are called two-ranked, or distichous [dis-ti-kus].
Alternate leaf arrangements
Most of the time, alternate leaves take turns along the length of a stem, going from side to side. In some cases, such as magnolia, alternate leaves occur on all sides of a stem, in an apparent spiral. Closer inspection will show that it is not a true spiral.
Leaf arrangement math
The fraction of a circle used to arrange leaves around a stem is very species specific. You don’t have to be a math whiz to understand this stuff, either. Let me explain:
Now look at leaf arrangement along and around a stem in the same way:
Are you with me? Hang in there! This stuff is amazing!
So, since leaves and stems are different sizes, and species have different sunlight needs, there are different fractions, or ratios of rotation, around a stem. For example, hazel leaves are arranged in 1/3 (or 120°) rotations, apricots use 2/5 rotations, sunflowers and pears use 3/8, and almonds use 5/13. This means that the leaves of an almond tree are positioned 5/13th of the pie apart. If you do the math, this works out to 38.5° between each leaf attachment, as you work your way up or down a stem.
This is where it gets really weird!
The fractions that describe leaf arrangement are almost always made with a Fibonacci number and its successor, as the numerator and denominator, respectively. Now, the number of steps taken for a leaf arrangement to work its way around a stem, before repeating the pattern, is called its gyres. A three leaf cycle of rotation has one gyre, while a five leaf cycle takes 2 gyres. The number of gyres ends up being the numerator in the Fibonacci number that describes the rotation! Holy spring bulbs, Birdman!
Whorls take this math to a whole new level
The rotation of successive whorls is nearly always one-half the angle between the leaves. For example, say you have a whorled leaf arrangement that uses three leaves. From what we calculated above, there would be 120° between each of those leaves, along the length of the stem. All the other whorls will be half that distance, or 60° apart from each other. I have no idea why.
Bottom line: whether leaves are alternate, opposite, whorled, basal, or distichous, the mathematics of leaf arrangement ends up providing each leaf with the optimal amount of sunlight.
[If you really love this stuff, check out Gray’s Botanical Textbook: Structural Botany (1879)]
Cabbage and rapeseed plants are probably not your first thought when it comes to fruit.
As strange as it may seem, the seeds and seed pods of the cabbage family are long, narrow fruits called siliqua (or silique).
Siliquose fruit anatomy
If allowed to bolt, or go to seed, members of the cabbage family produce long, skinny fruits, commonly referred to as seed capsules or seed pods. These pods are each made from two fused carpels. [Carpels are the female reproductive parts of a flower, consisting of the ovary, stigma, and style.] Ovules (seeds) form along the length of the carpels. These fruits look like pea pods, with two distinct sides, called valves. The valves are the outer walls of the ovary, also known as the pericarp. The juicy flesh of a peach and the hard outer shell of an almond are also made from the pericarp. Inside the siliquose fruit is a papery liner, called the septum. The line where the two valves meet is called the replum. When the fruit ripens and dries, it often pops open along this line, starting at the top. Since the two halves separate, these seeds are considered dehiscent.
If a seed capsule is more than three times as long as it is wide, it is called a silique, or siliqua. If a seed capsule is less than three times longer than wide, it is called silicle or silicula.
Magenta Spreen may sound like a great steampunk name, but this edible annual weed is probably already in your garden!
Also known as purple goosefoot, tree spinach, and giant lambsquarters, this local weed can reach 8 feet in height and takes practically no care. The fresh growing tips provide the best flavor (and they look amazing in a salad) but even the larger leaves can be steamed, the same way as spinach, and the seeds are edible, as well. Like rhubarb, spinach, parsley, and chives, magenta spreen contains relatively high levels of oxalic acid, but not enough to worry about.
The magenta spreen plant
Believed to have originated in India, magenta spreen made its way to China and then to other parts of the world, where it has long been a food plant. [In the 1500’s, magenta spreen lost out to spinach in the popularity race.] Cousin to chard, beets, and quinoa, magenta spreen (Chenopodium giganteum) is a chenopod that tastes like what you’d expect from a cross between spinach and asparagus. Like other chenopods, magenta spreen has triangular leaves, somewhat akin to a goose’s foot. Overall, the plants are green, but they feature iridescent, hot pink growing tips and new leaf edges. Magenta spreen can grow equally well in full sun or partial shade. If allowed to go to seed and flourish, it can be used as both an edible crop or as a green manure. It has no major pest or disease problems.
How to grow magenta spreen
If you live in the Bay Area, you have probably been pulling this plant out as a weed for years. Rather than ridding yourself of this visual and edible treat, simply let it grow! You don’t have to buy seeds, unless you’ve never seen it in your garden. In that case, plant seeds 1/2-inch deep in succession, starting in early spring or late summer. If plants bolt, let them. The seeds will provide you and your family with even more plants. They transplant easily, in case you don’t like where they start growing, or if you’d like to share with friends.
Have you seen magenta spreen in your garden?
Floral symmetry refers to whether or not, and how, a flower can be segmented into mirror images of itself.
Angiosperms (flowering plants) use a wide variety of structures, colors, and aromas to attract pollinators. These non-reproductive parts of a flower are called the perianth. The perianth consists of the petals (corolla) and the green cuplike structure at a flower’s base, called the sepals, or calyx.
Looking at a flower from above, if you were to cut it in half, through the perianth, the two halves might be relatively identical, identical only along one plane, or not identical at all. These different types of symmetry are called radial, bilateral, or asymmetrical, respectively.
Snowflakes and apple pies have radial symmetry. No matter how you cut them in half, both halves look the same. Flowers with radial symmetry are called ‘regular’ or actinomorphic. Actinomorphic also refers to ‘regular’ star-shaped flowers that can be divided into three or more identical sections. Each section looks the same, no matter how you rotate the flower. Even though each half may not contain a complete petal, they are still considered actinomorphic.
Most people have bilateral symmetry. This means our left and right sides look very much alike, but our fronts and backs look very different. Some flowers, such as orchids and snapdragons, are the same way. Some flowers have only one line that can be cut to create a mirror image. These flowers are classified as ‘irregular’ or zygomorphic. Zygomorphic flowers have bilateral symmetry and that line is called the sagittal plane. Lavender, olive, sage, mint, nasturtiums, basil, and rosemary flowers are zygomorphic.
Simple v. compound flowers
Flowers can be simple or compound, but don’t let the names fool you. Simple, or primitive, flowers, such as strawberries and geraniums, are actually more complicated than compound flowers. Simple flowers usually have 3 to 6 petals, sepals, stamens and pistils. Compound flowers, called inflorescences, are made up of hundreds or thousands of flowers, each with only one or two sepals and petals. To analyze compound flowers for symmetry, you would have to look at individual florets from that inflorescence. While sunflowers and dandelions may appear to exhibit radial symmetry, the actual florets may or may not be symmetrical, depending on the species.
Go take a closer look at the flowers in your garden. What sort of symmetry do you see?
The fruits and seeds that we eat are plant ovaries.
Botanically, an ovary is the enlarged base of a pistil. Pistils are the female reproductive organs of angiosperms, or flowering plants. A flower’s pistil can be made up of one or more carpels.
Parts of the ovary
Plant ovaries have walls that surround small eggs, called ovules. Ovaries often have chambers, called locules. Ovules are found inside the locule(s). Some locules contain fruit flesh, while others do not. The number of carpels also determines the internal structure of a fruit. When you cut open a melon, you will see one locule, in the center, and four distinct sections, which were formed by the carpels.
Plant ovaries and pollination
When pollen lands on the style (stalk) and stigma (sticky knob) of a flower, the pollen grain ‘germinates’, sending a pollen tube down to the ovule. This is pollination. When that pollen grain merges with the ovule, fertilization occurs. At this point, three new structures are produced: seeds, pericarp, and the plancetae.
Seeds Held within the ovary of a seed plant, are ovules. Ovules contain the female reproductive cells. Seeds are fertilized ovules. Fundamentally, ovules are the same thing as animal ovum, or eggs. This is the embryo sac.
Pericarp Pericarp is the thickened ovary wall that we call fruit. Plants use fruit flesh to protect the seeds, furnish young seedlings with nutrients, and to encourage seed dispersal by herbivores. There are three different types of pericarp tissue: exocarp (outer skin), mesocarp (flesh), and endocarp (inner layer). The dominant pericarp tissue can become hard, as with nuts, or fleshy, as we see in peaches and avocados. In some cases, we eat the pericarp. In others, we eat the seed. When we eat the pericarp, we call it a fruit - but not always.
Placentae The place where the ovules and the pericarp connect is called the placentae. If you look inside a tomato, the seeds are growing inside the placental area. The placenta also has an outgrowth, called an obturator, that feeds and guides the pollen tube.
Plants are classified by where their ovaries are found within the pistil, relative to the attachment of the petals and sepals. This point of attachment is called the insertion point. Ovaries can be superior, half-inferior, or inferior, and their flowers are described as hypogynous, perigynous, or epigynous, respectively.
Inferior ovaries To say a plant has inferior ovaries is not a genetic slur. Instead, it refers to fruits in which the seeds are located below the other floral parts, within the hypanthium. The hypanthium is a cuplike structure at the base of a flower, that surrounds or is attached to the gynoecium. The gynoecium (‘woman’s house’) is the female part of a flower, or pistil. Pumpkins, squash, cucumbers, pomegranates, bananas, pears, and apples have inferior ovaries.
Superior ovaries Superior ovaries are no better than other ovaries, they are simply found above the insertion point. Legumes, such as peas and beans, true berries, and plants that produce drupes, such as blackberries, raspberries, and soapnuts, feature superior ovaries.
Half-inferior ovaries Half-inferior ovaries are surrounded by the receptacle, with parts equally above and below the insertion point. Some botanists take this classification to the extreme, by saying a plant has a “two-fifth inferior ovary” but I think that’s taking things a bit far. Peaches, nectarines, and crape myrtles are in this group.
Take a look at the flowers in your garden that are destined to become fruits and nuts. Where is all the action taking place? Can you tell?
There’s no mistaking the licorice flavor of anise.
Anise or star anise?
Before we begin, let me clarify that we are talking about anise (Pimpinella anisum L. – anise burnet saxifrage), and not star anise (Illicium verum). Anise and star anise are not related. They do, however, both contain anethole, an oil that gives them their strong flavors. In each case, people often mistake the fruits from these plants for seeds. Tiny anise and star anise fruits are schizocarps. A schizocarp is a type of fruit that splits in half when dried. The two halves of a schizocarp are called mericarps. Star anise has a distinctive star-shaped fruit, while anise fruit is oblong.
Anise plants are herbaceous annuals that start out as bright green mounds. Then, feathery leaves shoot skyward, much like fennel. Being umbellifers, these cousins of carrots, dill, and celery have flowers that are large, flat clusters of tiny flowers that pollinators and other beneficial insects love. Plants can reach 3 feet in height.
How to grow anise
Being native to the eastern Mediterranean and Southwest Asia, anise is a warm weather, full sun crop. It prefers loose soil with good drainage, and a soil pH of 6.0 to 6.7, so it is better suited to raised beds in the Bay Area, unless you have improved your soil structure with plenty of aged compost. These plants have a taproot, so they do not transplant well. They can be grown in containers, as long as the pot is at least 8 inches deep and wide. Seeds should be planted 1/4-inch deep, at least two weeks after the last frost date. Thin plants to 12 inches apart. [Unless you really like anise, your family will probably only need one plant.] Regular irrigation is important, but an occasional top dressing is the only feeding these plants need.
Anise pests and disease
Larva of the wormwood pug, a small brown moth, will feed on anise foliage, but that’s about it. The oils that give anise its delicious flavor are the same components that most pests find offensive. Anise plants also have no major disease issues.
Anise leaves can be harvested as needed. Seed heads should be snipped while green and hung upside down in a warm, dark, dry location until they are completely dry.
Most people know that ‘deciduous’ refers to trees that lose their leaves each year, but there is more to the word and the process than meets the eye.
When a plant no longer needs a flower’s petals, those petals are allowed to fall away. When fruit becomes ripe, it is also allowed to drop. This act of ‘allowing to fall away’ is at the heart of deciduousness. Did you know that a deer’s antlers and your own baby teeth are also considered deciduous?
Pros and cons of deciduousness
Unlike evergreens, deciduous trees and shrubs, and some herbaceous perennials, lose their leaves each year. This is called abscission. In the Northern and Southern hemispheres, leaf drop normally occurs in autumn or early winter. In tropical regions, deciduous plants lose their leaves during the dry season. In each case, leaf loss occurs at a time when having leaves is not in the plant’s best interest. For example, broad-leafed hardwood trees might collect too much snow or ice in winter, causing limbs to break off, leaving open wounds, while tropical plants are unable to maintain heavy leaf cover without rainfall. This annual leaf drop is believed to be a mechanism by which some plants interrupt pests and disease triangles. It also means a plant must have enough food stored to last through the winter and to begin growing again in spring.
Another benefit of abscission is related to something called cavitation. Cavitation refers to times when water tension within a plant becomes so great [think rainy season] that the sap vaporizes within the tree and the oxygen held in that water expands rapidly enough to cause a loud ‘crack’ - you may have heard this, if you spend any time in forests. The problem with cavitation is that it damages the xylem. Plants can usually repair this damage, but not aways. One way deciduous plants protect themselves against cavitation is by dropping their leaves, which, in turn, allows them to have larger xylem vessels. These larger xylems allow deciduous plants to take up more water than evergreens in the summer months.
The chemistry of deciduousness
During spring and summer months, deciduous plants are busy producing chlorophyll, a green pigment. Shorter days (or drought stress) trigger plant hormones (auxins) to reduce chlorophyll production and to start drying the connection between the stem and petiole of each leaf. In some cases, the plant also withdraws the nitrogen and carbon held in those leaves for use in spring. Lower levels of the green pigment are what allow us to see other colors. Some of these colors, the yellow, brown, and orange carotenoids are always present, while red and purple anthocyanins are produced in autumn, as sugars become trapped in the leaves. These changes are triggered by shorter days and cooler nights. In areas without those conditions, the leaves simply dry up and fall off.
Deciduous trees and shrubs
Common deciduous trees include almond, pomegranate, quince, apricot, nectarine, peach, olive, persimmons, plum, fig, pear, walnut, and apple. Your grapes, kiwi, blackberries, raspberries, strawberries, and blueberries are also deciduous. In fact, nearly all fruit and nut crops occur on deciduous plants, citrus being a notable exception.
Winter is the best time to prune deciduous trees. [Except apricot and cherry, due to eutypa dieback.] The absence of leaves makes it easier to see the true structure of deciduous trees and shrubs, allowing you to see and remove dead, diseased, crossed, and poorly placed limbs. Winter is also the best time to apply dormant oil, to control many pests, such as scale.
Celery is a kitchen staple that you may (or may not) be able to grow in your home garden.
I say “may not” because it has thwarted me the few times I have tried it. Not that the plants didn’t grow, they grew quite well, through the cooler months, but they grew outward, rather than upward, and the flavor was very strong. Before we learn from what I did wrong, let’s learn the truth about this challenging crop.
A misrepresented edible
Celery plants have been misrepresented in elementary schools across the country for decades. The part we eat is not a stem, and the stringy bits that get caught in your teeth are not all plant veins. The familiar stalks, which are so well suited to dips and fillings, are actually the plant’s petioles, or leaf stems. Some of the differences between a stem and a petiole are:
Some of the indigestible strings of celery fame are vascular tissue, This is why, if you place a celery stalk in a glass of dyed water, you can see the dye move up, through the xylem. [Kids love this stuff!] The other stringy bits, however, are living structural components, called collenchyma. The tissues that make up the collenchyma are able to absorb water and behave much like a stiff gel, to hold the plant upright.
The celery plant
Celery (Apium graveolens) got its name from the Latin for ‘aromatic bee favorite’. As an umbellifer, celery is cousin to carrots, fennel, cumin, caraway, celeriac, parsnips, dill, parsley, anise, and poison hemlock. Celery flowers attract many pollinators and other beneficial insects, such as hoverflies. There are actually three different types of celery, each grown for a distinct crop: petioles, leaves, or roots. The celery plant originated in marshland - very unlike my hot, dry California summers, and only slightly moist winters.
How celery grows
Celery is a cool weather plant. It grows best when temperatures are 55 to 70°F. Grown in summer, it will bolt, or go to seed. This is fine, if you want to harvest celery seed for your spice cabinet. It is also a good way to end up with celery plants throughout your foodscape. Once a celery plant has gone to seed, the petioles will become very tough. [You can still use them to make soup stock, however.] Celery plants can tolerate light frost, but not consecutive frosts. Celery is a biennial, grown as an annual.
How to grow celery
While you can start a new celery plant from the base of a store bought celery, you need to be aware that those plants are certified safe to eat, but they are not certified safe to grow. Installing a store bought celery plant in your garden may be fine, and it may introduce a destructive virus or bacteria that may take years to overcome. It’s your call. Of course, you can always delegate those store bought celeries to indoor containers…
Celery is grown from seed. Seeds should be started 8 to 10 weeks before your area’s last frost date. You can also direct sow seeds in late summer for a winter crop. In either case, seeds should be planted 1/4-inch deep. Some growers recommend soaking seeds overnight prior to planting, to speed germination. Be sure to harden off your seedlings before planting them outside. Seedlings should be spaced 10 to 12 inches apart in the garden, containers, or raised beds, once they are 6 inches tall. If you have a particularly bright window, celery can be grown on a windowsill.
Celery needs lots of sun and it is a heavy feeder. You can protect and feed plants as they grow by top dressing around the plants with aged compost. Once petioles begin to emerge, you need to tie them together, to force them to grow upright. Celery needs least one inch of water a week to grow those crispy petioles. And they should be fed every 10 to 14 days. As the plants grow, gently build up soil around the plants, keeping the leaves exposed. This blanches, or etiolates, the stalks, by blocking light from reaching the chlorophyll, making them turn pale green to white. This also help prevent bitterness. You can get a similar effect by wrapping plants with straw, heavy fabric, or cardboard tubes, the same way you would with cardoons, to halt photosynthesis. Be cautious when watering, after you have set up your planting method. Water that sits on leaves and stems can lead to rot and other problems.
Celery pests and diseases
Celery is susceptible to aster yellows, bacterial leafspot, Phytophthora tentaculata, blights, mosaic virus, fusarium wilt, pink rot, and crater rot. Aphids, armyworms, earwigs, leafminers, lygus bugs, carrot rust flies, nematodes, whiteflies, treehoppers, cutworms, and voles will all take a bite out of your celery plants. You can sprinkle your celery plants with diatomaceous earth, to reduce many of the pests.
Like peanuts, celery is known to cause allergic reactions in some people. Contrary to popular wishful thinking, eating celery is not a 'negative calorie' experience. Digesting that celery stalk does not use up more energy than it provides.
Finally, did you know that celery flowers and leaves were used as garlands for King Tut’s tomb, some 3,300 years ago? I didn’t, either.
If you have citrus trees, you probably have citrus mealybugs.
Cousin to scale insects, these tiny pests are often overlooked. At first, all you may see is some sooty mold on a few leaves, an ant trail, marching up and down the trunk of the tree, or, finally, the telltale cluster of fuzzy white, tucked under leaves or in crevices. Left unchecked, mealybugs can scar fruit, and cause chlorosis (yellowing), early leaf and fruit drop, and poor overall tree health.
Citrus mealybug varieties
There are actually four different mealybugs that attack citrus in the Bay Area:
Citrus mealybug description
All mealybugs are soft, flat, oval-shaped critters with segmented bodies. The mealybugs that attack citrus are covered with a white wax that also creates spines (filaments) around the outer edge and the back end. Unless you use a hand lens, you probably won’t notice individuals, but mealybugs colonize areas, creating white, fuzzy egg clusters that are easy to spot.
Male citrus mealybugs are not needed for reproduction, but they are needed by long-tailed mealybugs. When mealybug eggs hatch, the 'crawlers' are pale yellow, with red eyes, and distinct antennae. Crawlers are not born with their protective wax coating. They begin to excrete it soon after hatching. They are called crawlers because they crawl to a feeding site, where they will continue to develop (and damage fruit) for a month or two.
Citrus mealybug damage
Each female mealybug can lay hundreds of eggs, and there are usually two or three generations a year, so infestations can become a problem. As sapsuckers, citrus mealybugs pierce fruit, leaves, and young stems, to get at the sap. They also feed on tender, new growth. As they feed, they leave behind a trail of honeydew that attracts protective ants, and creates the perfect growth medium for sooty mold. Citrus mealybug feeding near fruit stems also leads to fruit drop. Citrus mealybug feeding also reduces fruit quality. Trees fail to thrive and are prone to infestation by disease and other pests. In addition to oranges, lemons, limes, and grapefruit, citrus mealybugs also have a taste for ornamental plants, such as tulips, coleus, cyclamen, begonias, and dahlias.
How to control citrus mealybugs
The first step to controlling citrus mealybugs is to monitor your trees, especially in spring and fall, for signs of ant trails, sooty mold, and egg clusters. Since ants will protect and farm the aphids for their honeydew, apply sticky barriers to tree trunks to block ants from protecting the aphids against their natural predators. Those natural predators are your trees’ best defense against citrus mealybugs. Ladybugs, lacewings, and hoverflies will devour these pests, so avoid using broad-spectrum pesticides. For extreme infestations, you can buy an introduced predator, called the mealybug destroyer (Cryptolaemus montrouzieri). Insecticides are not recommended. Diatomaceous earth and insecticidal soaps can be used.
Mealybugs prefer dusty conditions, so hosing trees off can make them less appealing to citrus mealybugs.
You can grow a surprising amount of food in your own yard. Ask me how!