Mummy berry is not a seasonal breakfast cereal. Instead, it is a fungal disease of blueberries.

The Monilinia vaccinii-corymbosi fungus is nearly always present in the soil. And a cool, wet spring can set the stage for crop losses.

Symptoms of mummy berry

A healthy summer blueberry bush is thick with leaves, twigs, blossoms, and fruit. After a cool, wet spring, you may notice that some of the blueberries shrivel up, turning hard and gray. Before the fruit even appears, you may see a coating of brown or blue spores on the veins of infected leaves. You may also see drooping, wilting, brownish flower clusters that are turned in on themselves before they turn brown and die. Immature fruit falls to the ground, and twig tips become blighted in a condition called shoot strikes and die. These are all symptoms of mummy berry.

Mummy berry life cycle

Tiny cup-like mushrooms (apothecia), also known as trumpets, growing around the base of your blueberry bushes at budbreak often indicate mummy berry. These mushrooms emerge when temperatures range from 50 to 57°F, so check your thermometer regularly in spring. As the cup openings of these fungi reach a diameter of 2mm, they can start infecting your plants. 

A week or so after budbreak, new vegetative shoots emerge. In both cases, this tender new tissue is vulnerable to infection. The mummy berry mushroom spews fungal spores into the air. Spores land on all this new plant tissue. Pollinators, wind, and water may also carry spores to your blueberry bushes. Once the fungi reach your blueberries, they need adequate moisture to grow. The longer they stay wet, the faster they grow.

​Cut open an infected green berry to see white fungal tissue. Afterward, sanitize your cutting tools with a household cleaner to prevent spreading the infection further.

Controlling mummy berry

Once infection occurs, remove any diseased tissue and throw it in the trash. You can reduce the chance of mummy berry causing too much damage in your garden with these tips:

• Remove all blueberry mummies & diseased stems.
• Regularly monitor plants for signs of mummy berry.
• Irrigate plants properly and avoid overhead watering.
• Mulch with 2 inches of Douglas fir sawdust.
• Rake the area around blueberry plants each spring.
• Remove weeds.
• Select resistant varieties.
• If necessary, apply fixed copper or Bordeaux mixture.

Resistant blueberry varieties

Some blueberry varieties are more resistant to mummy berry than others. According to the USDA Agricultural Research Service, low bush varieties with less than 3% mummified berries include:

• Brunswick
• Chignecto
• Fund
• Putte
• Zuckertraube

A mummy berry-resistant group of varietals called half-highs are crosses between low and high bush varieties. These include Chippewa, North Country, Northsky, and St. Cloud.

Resistant highbush cultivars that rated the best with 10.3% or less mummified berries include the following:

• Bluegold
• Bluejay
• Brigitta Blue
• Patriot
• Reka
• Reveille
• Weymouth

However, high bush varietals are generally not recommended for warmer regions. They need more chill hours than those areas get. A cross between a southern highbush and rabbiteye blueberry, called Pearl River, is resistant to mummy berry. Berkeley variety seems to be the most vulnerable to mummy berry infection.

To enjoy the lush, sweet flavor of blueberries in summer, install the most resistant variety suitable to your microclimate.

Witches' brooms are a common sight in autumn landscapes, but there is one variety you never want to see in your garden.
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Symptoms of witches' broom

From a distance, witches' broom looks like a squirrel nest or an area of particularly dense foliage. Closer inspection reveals a distinct twig deformity, a clustered riot of shoots pointing in every direction. The stems found in a witches' broom may also be twisted, discolored, or dwarfed.

Causes of witches' broom

Witches' broom can be a symptom of chemical overspray, disease, such as aster yellows, a hormone imbalance, mistletoe, mites, nematodes, a zinc deficiency, or feeding by bacterial plant parasites called phytoplasmas. First seen in 1967, phytoplasmas have been impossible to recreate in the laboratory, which makes studying them and developing control measures difficult. 

The hormone imbalance that causes witches' broom is a battle between auxins, which regulate plant cell growth, and cytokinin, which regulates cell division. There isn't much you can do about many of those conditions. But not all deformities are undesirable.

The good witch

Sometimes a witches' broom is more of a dwarf version of the parent tree. Very often, that dwarf version can be removed and propagated. Many of our modern dwarf conifers got their start in this way.

Discarded limbs, scattered petals, seeds and fruits thrown to the ground - abscission!

Abscission is the intentional shedding of body parts. Some lizards do it with their tails, we do it with our teeth, and mushrooms do it to their spores. All plants use abscission as a normal part of their lifecycle, but for different reasons and in different ways.

Anatomy of abscission

The area where abscission occurs is called the separation zone, or the abscission zone. When abscission occurs, enzymes are released that breakdown the structural cellulose and the adhesive pectin within cells in the abscission zone. The timing and methods of abscission depend on the reasons behind the action.

Forms of abscission

There are four basic forms of abscission:

• seasonal - deciduous trees shed their leaves each fall to avoid snow load in winter; fruit drop occurs to focus resources on fruit yet to come; dandelions and other flowers and fruits shed seeds to continue the species
• conservation - damaged leaves or twigs are dropped to reduce water loss in drought, or in response to shade tree decline
• defense - plants may drop heavily infested leaves or blossoms to rid itself of some pests
• senescence - natural aging

Artificial scarification

Commercial agriculture relies heavily on crops that grow and reach maturity at a consistent rate. It’s the only way to take advantage of the economies of scale provided by heavy farm equipment and large acreages. Scarification can help farmers get crops to grow uniformly by triggering seeds to germinate at the same time with these artificial forms of scarification:

• Mechanical scarification - the outer seed coat is cut or nicked with a file or knife, rubbed with sandpaper, given a gentle whack with a hammer, or placed in a container a shaken within an inch of its life [Research has shown that this ‘percussive scarification’ results in 90% germination, as opposed to 50% germination from chemical scarification.]
• Chemical scarification - household bleach, vinegar, sulfuric acid, and potassium nitrate have been used to chemically carve access into a seed’s innards
• Thermal scarification - boiling water, smoke, and fire can be used to compromise the integrity of a determined seed

Before you plant a seed, learn as much as you can about its natural life cycle. This information can help you decide if scarification is a good idea.

Just be careful not to harm the seed within (or your fingers)!

Onion maggots are the larval form of the Delia antiqua, or onion fly.

Onion maggot description
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Onion flies are brownish gray versions of your average housefly, only smaller. The males have a stripe, but females do not. At rest, these flies tend to fold one wing over the other. Eggs are long white ovals. And the larval form, or onion maggots, are creamy white, legless, and a little less than 1/2 an inch long.

Onion maggot lifecycle

Adult flies lay eggs on leaves, shoots, and bulbs of host plants. These hosts include onions, leeks, and, to a lesser extent, garlic. Flower bulbs are also susceptible to onion maggot feeding. When the eggs hatch, onion maggots start feeding and feed they do! You can find up to 50 onion maggots in a single bulb! After they have eaten their fill, the larvae move into the nearby soil where they will pupate. These damaged areas provide points of entry for many other fungal and bacterial pathogens.

How to control onion maggots

Crop rotation is your best defense against onion maggots. Since the adult forms can fly, there is only so much you can do. Row covers may help, but it is difficult to time their use properly. Yellow sticky traps can be used to monitor for adult flies.

Luckily for most gardeners, cold, wet winters slow larval growth. More damage occurs while onions are in storage than in the field. You can protect your onion harvest from damage by thoroughly brushing off onions before putting them into storage, and regularly monitoring harvested onions.

Cabbage maggots are a serious pest of plants in the cabbage family (Brassica).

What starts out as a single, tiny fly can turn into 300 squirming, gnawing slugs of destruction in just two or three days. And you may never see them before it is too late. Cauliflower and Brussels sprouts are more likely to be attacked, but broccoli, cabbage, turnips, radishes, rutabagas, and mustard plants are also vulnerable, especially in cool, wet weather.

Cabbage maggot description

Cabbage maggots are the larval stage of the cabbage fly (Delia radicum). Also known as cabbage root flies, root flies, or turnip flies, this dark gray fly is half the size of your average house fly. Maggots are white, legless, and only 1/3 of an inch long, with a pointed head and a blunt behind. Eggs are white and 1 mm in diameter.

​Cabbage maggot lifecycle
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Eggs are laid in the soil, around the crown of host plants. When they hatch, larvae (maggots) start feeding on fibrous roots and burrowing into taproots. This feeding facilitates entry by pathogens that cause blackleg and bacterial soft rot, and it continues for three weeks before maggots pupate in the soil. In two to four weeks, adult flies emerge to feed on nectar and the whole cycle begins again.

Symptoms of cabbage maggot feeding

These pests are easy to miss, but the damage they cause is obvious. As seedlings and young plants struggle to survive, chlorosis (yellowing), stunting, and even death may occur. Infested root systems are sparse and taproots show obvious tunneling. Established plants are better able to withstand attack, but they will also show stunting and chlorosis. Wilting in the middle of the day can also be a sign of cabbage maggot feeding. Plants will perk back up by morning, but, within a few days, they will be dead. Dark green leaves may show a bluish tinge, but that can be a normal feature of some plant varieties, so don’t use it as a symptom unless other signs are visible. Infested plants should be removed and destroyed. Do not compost infested plants.

​Cabbage maggot control

If cabbage maggot carnage is something you need to control, spinosad is moderately effective, according to a 2015 UCANR study. Traditionally, fumigation was used, and organophosphates (diazinon and chlorpyrifos) were applied to soil in concentrations heavy enough to contaminate ground water and kill off non-target species. Obviously, more environmentally safe, sustainable methods are needed. Many of the other insecticides that performed the best in the study are unavailable to the home gardener, and for good reason. You can reduce the likelihood of infestation by using crop rotation, row covers, and proper irrigation.

If you are determined to protect your cole crops, you can also use brassica collars around the base of each plant. A brassica collar is simply a flat piece of plastic, thick cardboard, or heavy fabric that covers the soil around the base of a plant. Cabbage flies are unable to lay their eggs as close as they would like, and many of the larvae simply starve to death before they reach your plants. You can make your own brassica collar, just be sure that the collar opening can be enlarged as the plant grows.

Banding is a way to help your seeds get a better start on life.

As much as making music is a great way to expand your mind and improve your math skills, banding in the garden has nothing to do with tempo or harmonics. Banding refers to the practice of incorporating fertilizer in the soil close to your seeds at planting time. Just picture, in your mind’s eye, a band of seeds planted in the ground, with a band of fertilizer right next to them. As new roots grow, they are sure to find a good meal to help them get big and strong.

It makes obvious sense, but you do have to be a little careful. Banding falls into the “too much of a good thing can be a bad thing” category. According to Montana State University, benefits of proper banding include:

• higher overall crop yield
• less weeds, and plants better able to compete with weeds
• higher fertilizer efficiency

How to band seeds at planting time
​
Unlike top dressing, which means leaving aged compost or fertilizer on top of the soil, banding requires a little more effort. For the home gardener, we don’t need to get too particular about the depth. Professional, large-scale farmers have this down to an art and science, but we can safely apply our banded fertilizer 3 or 4 inches deep, 1 to 3 inches on either side of the row of seeds being planted. These “starter fertilizers” make valuable nutrients available to early roots, helping the seedling to reach its full potential. Before you jump on the fertilizer band wagon [Sorry, I couldn’t resist], you need to find out what you are working with and which fertilizers are best for your plants.

​I’ll say it again: soil test!

You can’t know what to add if you don’t already know what you have. Your soil may have an abundance of phosphorus. Adding more could be detrimental to your plants, and it’s a waste of money. Adding unnecessary fertilizer also puts the environment at risk, you know, global health and all that. Find a reputable, local soil test company and use them. The results are really fascinating and useful. [Over the counter soil test kits are not reliable or useful. Yet.] If your soil already has plenty of everything, banding is unnecessary. If your soil is lacking any of the Big Three plant nutrients, banding can help your seeds overcome this handicap.

Choosing the right fertilizer for banding
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All fertilizers are required to provide information about the percentage by weight of nitrogen (N), phosphorus (P) and potassium (K). Think about this for a moment. A 10-pound bag of 10-20-10 fertilizer contains 1 pound nitrogen, 2 pounds phosphorus, 1 pound potassium, and 6 pounds of filler. After you have gotten the results from your soil test, you can select the best fertilizer for your crop.

According to Pennsylvania State Extension, nitrogen and phosphorus are the “key nutrient components in a starter fertilizer.” If all your plants need is nitrogen, blood meal is an excellent choice. Be cautious with fertilizers that contain urea (46-0-0) or diammonium phosphate (10-34-0), as these substances can burn or even kill young plants.

So, find out what’s in your soil. If something is lacking, put it where seeds are sure to find it with banding!

Turnips are a white, cool weather root crop.

Cousin to rutabaga, radishes, and other members of the cabbage family, turnips (Brassica rapa) are grown for the bulbous taproot that looks more like a beet, except that it is white, and its nutrient rich leaves.

Fun turnip trivia: the pink, purple, red, or greenish color of a turnip’s shoulders is a result of being exposed to the sun.

Taste for turnips

Many people believe that they do not like turnips, but this is often because the turnips they tried were too old. Old turnips taste bitter. This is because of a self-defense chemical produced by many members of the cabbage family. Also, some individuals have inherited a pair of genes that make them extra sensitive to the bitterness, so don’t force anyone to try the fruits of these labors. It just might not be possible for them to enjoy the flavor. That being said, young, tender turnips do not contain as much of the bitterness, so harvest early and often! Also, consistent irrigation reduces the chance of your turnips becoming bitter.

Turnip greens

Turnip leaves are a popular side dish in the southeast. Tender leaves are less bitter than older leaves. Bitterness can be reduced by pouring off the cooking water and replacing it with fresh water and reheating. Unlike rutabagas, which have a visible crown or neck between the taproot and the leaves, turnip leaves grow directly from the root.

How to grow turnips
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Like other root crops, turnips prefer loose soil, but they are resilient plants. They can handle conditions that thwart more gentle crops. Turnips can be planted late winter through early spring and again in late summer and early fall. Seeds should be planted 1/2 inch deep, directly into the garden. Seedlings should be thinned to 4 to 6 inches apart, when grown for roots, and 2 to 3 inches apart for greens. Depending on the variety planted, your turnip crop should be ready within 50 to 75 days. Tokyo turnips, which tend to be smaller, are harvestable after only 30 to 60 days!

Turnip pests and diseases

As a Brassica, turnips are subject to attack by caterpillars, whiteflies, cabbage loopers, Bagrada bugs, beet armyworms, and aphids. Aphids can also carry turnip mosaic, a viral disease common to Brassicas. Row covers can prevent damage, but only if they are installed before the problem starts.

Turnips have been grown for over 4,000 years. Pliny the Elder ranked turnips third only to cereals and beans as the most important crops. Turnips were also used in early experimentation with crop rotation.

Give turnips a try in your garden today!

Just as straw is left behind after a crop of oats, alfalfa, or wheat is harvested, stover was traditionally left in the field for cattle or other grazers. Some modern mushroom farmers use stover as compost for mushrooms. Dairy farmers often use stover to create silage. Silage is plant material that is cut and crushed and then stored in a relatively airtight silo without being dried ahead of time. This fodder ferments, making more easily digestible. But, I’ll bet that you do not have a silo in your backyard, or cattle to feed. So, what can you do with your stover at the end of the growing season?

Compost

The first and easiest use of stover is to add it to the compost pile. Stover often consists of half of your crop. That’s a lot of plant material. Held within that material are nutrients that other plants can use, but only if the stover has broken down. You can compost stover by cutting the heavy stalks into one-inch pieces and keeping it near the bottom of your compost pile. For shorter crops, such as millet and sorghum, I simply cut the plants off at ground level and toss it all to my hens, who make short work of the greens. [The sorghum comes back each year for a continuous supply of greens and seeds for my hens and I always manage to miss some of the millet seeds, so they pop back up each spring, as well.]

Stubble cultivation

In commercial agriculture, stubble cultivation refers to the act of plowing all that stover back into the earth. This returned the nutrients back into the soil and improves soil structure (assuming the heavy farming equipment doesn’t compact the soil too much). In my mind, stubble cultivation is a twist on the Three Sisters Method of planting. Rather than cutting down tall stalks of corn or sunflower, these sturdy poles can be put to work. Simply plant cool weather climbing plants, such as peas, at the base of each stalk. The petioles (tiny stems that attach leaves to bigger stems) make perfect handholds for tiny tendrils. The peas grow up and up and up and you don’t need to install or maintain a trellis! After your pea crop is harvested, you can cut the stalks off at ground level, chop them into bits, and add them to the compost pile. Or, you can use them again, as bean poles!

​Bean poles

Whether you leave the stover in place or cut it off at ground level, these sturdy poles can be used to grow pole beans in the following spring. If you leave the stalks in the ground, simply repeat the pea planting process, but with pole bean seeds. If you prefer cutting the stalks of stover, you can create a pole bean teepee by lashing the tops of several stalks together and spreading them out at the base over several bean plants.

​Other uses for stover

There are other creative ways to repurpose those tall, study stalks before they need to be composted. Here are some of my favorites:

• dog chews - one of my canines loves to gnaw on these tough stems; when he’s done, I sweep up the remains and toss them into the compost pile
• chicken run flooring - I leave my sunflower stover on the ground in my chicken run, near the chicken drinking fountain, to keep the hens’ feet out of the mud during the rainy season
• kids’ teepee - especially tall stalks can be used to create a fun kids’ teepee, just add a sheet for instant fantasy!
• swords and fencing - another children’s activity is to transform stover stalks into swords and light sabers for battle play
• kindling - stover makes excellent kindling for those chilly weather nights (Spare the Air alerts permitting, of course]
• musical instruments - follow the example of many Native American cultures and try your hand at using these fibrous stems to make percussion or flute-like instruments
• trellises - weave the stalks into a natural trellis that can easily last 2 or 3 years
• drying racks/poles - being so sturdy, long stover stalks can be used to dry herbs for later use

How do you put your corn and sunflower stover to use? Let us know in the Comments!

Parsnips are a cool weather crop in Mediterranean climates. Parsnips can be planted in September, and then again in February, March, and April in our region. If you live in a different area, simply check with your local Cooperative Extension Office for your best planting times.

Parsnip plant description

Parsnips leaves look almost like ferns, with pinnate (branched), toothed edges (margins). Parsnips are grown as annuals, but if you let a few of them go to seed, these biennials can start spreading edible roots in many areas of your foodscape. [Once they start that process, you won’t want to eat them - they get quite woody.] Second year plants can grow 5 feet tall, but your first year parsnip will be significantly shorter, at only 18 to 24 inches. Yellow, umbrella-shaped flowers grow into tiny ‘fruits’ called schizocarps. [How’s that for a fun garden word?]

​How to grow parsnips

Parsnips, like other root crops, need loose soil. This makes them well suited to raised beds and container gardening. If you are planting parsnips in heavy clay soil, you will want to break up the soil down 18 inches and dig in 3 or 4 inches of aged compost. If you don’t, you will end up with forked and otherwise deformed roots prone to disease. Parsnip seeds should be planted 1/2 inch deep, with a heavy dose of patience. Parsnips seeds are slow to germinate and the plants take up to 4 months to reach harvestable size, but they are worth the wait! These sweet roots lend themselves to seasonings such as ginger and nutmeg, as well as more savory dishes, such as soups and stews. Parsnips can be grown in full sun or partial shade. They prefer slightly acidic soil, so you may need to make some pH adjustments. Seedlings should be thinned to stand 3 to 6 inches apart and be sure to eliminate all competition from weeds.

Persian limes with brown bottoms have stylar end rot.

Also known as stylar end breakdown, stylar end rot primarily affects Bearss, Tahitian, and other Persian lime species but can occur in other lime and lemon varieties. Stylar end rot found on guava is a fungal disease.

Stylar end rot is a physiological disease caused by too much heat. Even though limes, lemons, and other citrus have thick, waxy skins to protect themselves from the sun’s heat and drought conditions, sometimes that protection isn’t enough.

Symptoms of stylar end rot

The stylar end of a fruit is the part with the dried-up petals. It is opposite the stem end. Stylar end rot starts as a small, grayish sunken area that slowly becomes firm and leathery. Some fungal diseases exhibit similar symptoms:

• Alternaria rot—fruit looks ripe when it isn’t; inside is rotted
• Anthracnose—soft, sunken brown areas with visible white fungal growth
• Brown rot—starts as stinky tan or olive brown lesions anywhere on the fruit
• Blue (green) mold—also known as clear rot; anywhere on the fruit

Affected areas can spread to cover 1/4 to 1/2 of the fruit. Bacteria and fungi often infect these compromised areas. The tissues inside break down and turn brown or pink. Diseased fruit can go in the compost pile, but only if it is free of other fungi and bacteria. Otherwise, toss it in the trash.

Preventing stylar end rot

You can’t. Stylar end rot occurs when vulnerable citrus fruits experience an accumulated 18 hours of temperatures over 105°F. Think of it as reverse chill hours. Pick the fruit earlier, after particularly hot summers, and hope for cooler weather next year.​

Mealybug destroyer identification

Like their close cousin, the lady bug, mealybug destroyer adults have the same dome-shaped body and short, stubby antennae. [That's a pretty cute little face, too, wouldn't you agree?] Mealybug destroyers, however, have black wing cases (elytra), with orangish-brown shoulders and rear end. Adults are only 1/6 of an inch log, so you may never notice them. If you decide to take a closer look with a hand lens, you might be able to see that females have dark brown forelegs and males’ forelegs are light brown. The larval forms, which can reach 1/2 inch in length, are often mistaken for wooly aphids or mealybugs, because of their elongated, alligator shape and waxy, white filament covering. Yellow eggs are laid near mealybug eggs for easy access to their favorite food supply.

Mealybug destroyer diet

A single mealybug destroyer may eat 250 mealybugs in its short lifetime. They also feed on soft scale insects. And it is not just the adults who hunt down and kill our garden enemies. While adults chomp and chew, larval forms pierce and suck the life juices from many sap-sucking garden pests.

Mealybug damage

So, why would a gardener care about mealybugs? Cousin to aphids and whiteflies, mealybugs are sap eaters. They feed on new buds, shoots, and leaves, causing erratic or reduced budbreak, slowed growth, and twig dieback. Mealybugs are frequent pests to basil, grapes, stone pine, pomegranate, chamomile, apple, plum, pear, peach, ferns, orchids, and, well, quite honestly, pretty much everything growing inside or outside of your home. Mealybugs produce honeydew, which provides the perfect growth medium for sooty mold. They can also carry bean mosaic. That’s why.

Attracting mealybug destroyers

It is highly unlikely that there are any mealybug destroyers in your neighborhood to attract. They simply cannot handle winter weather. So, you will probably have to buy mealybug destroyers each spring. What you can do, to prevent them from flying away as soon as they arrive, is to provide biodiversity. This means installing a wide variety of plants, with various heights, shapes, and colors. And avoid those broad spectrum insecticides.

Mealybug destroyers may not occur naturally in your home garden, but they sure can help maintain the balance of power in your foodscape!

Flea beetles hop and fly from plant to plant, chewing tiny holes in leaves as they go.

Flea beetle damage

Pitting and small, irregular holes in leaves may merge to create raggedy areas. The holes are smaller than the damage caused by shot hole disease. Shot hole disease holes usually begin as 1/10 to 1/4 inch diameter red or purplish spots. 

Flea beetle feeding holes may have a pale green or yellow ring. Those spots will dry up. The dead tissue then dries up and falls away, leaving a shotgun blast appearance. Small, irregular leaf holes may also be caused by springtails, though it is more likely to be flea beetles. Flea beetles may also damage fruits and root systems.

Flea beetle lifecycle

Flea beetles lay tiny eggs in weeds, plant debris, and the soil surrounding their favorite food plants. After the eggs hatch into thin, white larvae, feeding may begin above or below ground. After a month or so, larvae pupate in the soil. When they emerge as adults, they use their big jumping legs and wings to go wherever they want to feed.


Flea beetle control 


Pesticides are not very effective on flea beetles. In most cases, control isn’t necessary. If an infestation starts to cause serious damage, use basic sanitation in the garden. Removing all those tiny hiding places can make life difficult for flea beetles. Reflective mulch and white sticky traps can also be used to manage flea beetles. Row covers may block pests from reaching plants in the first place. Once they are present, you can lightly sprinkle the area with diatomaceous earth (DE). Flea beetles don’t care too much for sulfur, either.

​Some commercial growers vacuum off heavy flea beetle infestations, but I don’t recommend it for the home gardener. Your vacuum cleaner would never be the same!

Chinese cabbage refers to two different cool weather crops that lend themselves to areas with mild fall and winter weather.

Chinese cabbages (Brassica rapa) are variations on the lowly turnip. The two subspecies we most commonly see are forms of Napa cabbage (var. pekinesis) and bok choy (var. chinensis). These healthful foods have been grown in China since before the 15th century.

Bok choy

Unlike the Napa cabbages, bok choy does not form heads. Bright white stalks give way to dark green blades, growing in a cluster, much like celery. Bok choy can be planted in late summer and early fall, and then again, late winter through early spring.

How to grow Chinese cabbages

These biennial plants are generally grown as annuals. If you allow your plants to go to seed, you can create a seasonally perpetual crop within your landscape. To begin, find a location with full or partial sun and well-drained soil. Adding aged compost to the planting bed ahead of time can provide a nutritional boost to your plants and improve soil quality, while you’re at it. Chinese cabbages can also be grown in containers. Use pots that are 8 to 12 inches across and 18 to 24 inches deep. Seeds should be planted 1/2 inch deep and successful seedlings should be thinned to 12 - 18 inches apart. These plants do not transplant well, so it is better to put them where you want them right from the beginning.

Pests and diseases

Being closely related to broccoli and cauliflower, Chinese cabbage is subject to many of the the same pests: aphids, flea beetles, armyworms, loopers, cabbageworms, leaf miners, and millipedes. Common diseases include white rust, damping off, yellow virus, clubroot, black rot, and bottom rot. Many of these diseases can be prevented by allowing soil to dry out between waterings.

Harvesting Chinese cabbages

Chinese cabbages are good candidates for succession planting. If you start one new plant per person every two weeks, through fall and winter, you will have an abundance to harvest. You can extend that harvest by only cutting away outer leaves on an as-you-need-them basis. These plants will continue to produce inner leaves through the growing season.

Storing cabbages

Like other cabbages, these plants to not produce a lot of ethylene gas. Ethylene gas is what makes fruits and vegetables ripen. Cabbages are, however, very sensitive to the ethylene gas produced by other plants, so it is a good idea to keep harvested leaves or heads in a plastic bag in the refrigerator. Or, your can always try your hand at fermenting some cabbage for your very own kimchi!

Idioblasts are specialized plants cells that are very different from the cells around them.

Most plant cells are grouped together with other, similar cells: leaf cells with leaf cells, root cells with root cells, and so on. Hidden within these normal groupings are cells called idioblasts.

Scientists believe that idioblasts are the precursors to many specialized cells, such as stomata, glands, and guard cells. When idioblast cells divide, they often create daughter cells different from themselves. These mutations have given rise to much of the diversity within the plant world. At the same time, many idioblasts have remained the same over time, providing important functions within a plant. According to Albert Paul Kausch, in his 1985 doctoral thesis, The development, physiology, and function of selected plant calcium oxalate crystal idioblasts, no one really knows how or why idioblasts form.

Most commonly, idioblasts are storage cells. But some idioblasts hold a defensive arsenal of poisons and pointy crystals! ​

When botanists and scientists talk about idioblasts, they divide them into several groups, depending on function.

Storage idioblasts

Some idioblasts are simply storage cells. They may store pigment, food, waste products, water, resin, latex, oil, or tiny stones of silica (phytolith). Until recently, it was not understood why plants contained silica. Then, some scientists tried growing plants in soil without any silica. Many of these plants flopped over. Mystery solved. Sort of. Then, another group of scientists, led by Fergus P. Massey, proposed that plants evolved to contain silica for more than just structural support. They claim that plants absorb these minerals as a defense mechanism. Massey and his team point out that silica in plants tends to wear down the teeth of those who eat them. There is debate about the truth behind this assumption. You decide.

Idioblasts as manufacturing centers

Other idioblasts do more than just store materials. Some idioblasts actually manufacture important compounds. For example, avocado skins have idioblasts with antifungal properties. Other idioblasts produce mucilage carbohydrates (mucus cells) that store water. Other idioblasts, called phenolic cells produce and store carbolic acid to be used as defensive weapons.

Idioblasts as weapons

While we consider herbivores to be mostly harmless, plants do not share that view. Rooted to one location, and without claws or fangs, plants have to get creative when it comes to defending themselves against grazers and other plant eaters. This is where idioblasts get really interesting. Some idioblasts contain biforine cells. Biforine means having two doors. [Isn’t that a great word?] These cells are oval-shaped with openings at each end. When something (or someone) bites the plant, breaking the cell, crystals of calcium oxalate shoot out, poisoning or irritating the attacker! These oxalates are produced in the vacuoles of the idioblasts. Oxalates are toxic to the plant, too, but the plant protects itself by binding the material up in crystals. These crystals come in many shapes. They may look like a grain of sand, a pencil (styloid), a needle (raphide), or prismatic (isodiametric). Bundles of raphides or prismatics are called a druse.

Plants that use these weapons

Many plant families rely on druses stored in idioblasts for protection. These families include:

• Aeonium - succulents
• Allium - onion, garlic, leeks, chives, and scallions
• Morus - mulberries
• Phaseolus - beans
• Prunus (stone fruits) - plums, peaches, nectarines, cherries, apricots, and almonds
• Rosa - roses
• Vitis - grapes

Botanists believe that plants also use these calcium oxalate-filled idioblasts to provide structure to the plant, and as a way to store calcium.

This information may not help your grow brighter flowers or more delicious tomatoes, but your mind needs to grow, too! And who can resist a word like idioblast?

We all think it won’t happen to us. Fires happen elsewhere, to other people. And then fire strikes closer to home, devastating everything in its path. The time to protect your home and your family is before temperatures rise. The time to garden for fire safety is now.

Drought and climate change have killed hundreds of millions of mature trees in North America. In California alone, over 102 million trees died between 2010 and 2017. Many of the remaining trees are not as healthy as they could be. Trees weakened by drought, disease, and bark beetle infestations are more susceptible to fire.

Fire in landscapes

​You learned it back in elementary school: fire needs fuel, heat, and oxygen to keep going. A single spark can land on dry grass, move to a shrub, climb a tree, and then leap to your home, taking everything you own with it. It can also take your life. Gardening for fire safety means interrupting that spread. Rather than allowing a fire to move through your landscape using shrubs and trees as a superhighway, you can create spaces that slow or stop the flames. 

Many state laws require that rural homes have a 100-foot defensible space. Suburban homes face different challenges, but fire safety is still critical. Many of the suggestions still apply. Since each county has its own set of ordinances, check with local authorities. Even without the law, fire safety around your home simply makes good sense.

Defensible space

Defensible space can slow or stop the spread of fire. It also helps keep you, your family, and our heroic firefighters safe. That space consists of two zones: 

Zone 1 is a 30-foot perimeter around any structures. You can prevent fire in this zone with these tips:

1. Remove all dead vegetation.
2. Remove dry leaves and pine needles from the roof and rain gutters.
3. Prune tree branches to keep them 10 feet away from your home and each other.
4. Move patio furniture and other flammables away from trees and shrubs.
5. Move woodpiles and other flammable materials into Zone 2.

Zone 2 extends 100 feet from your home. Maintain Zone 2 with these practices:

1. Keep grasses mowed to 4 inches or less.
2. Rake up fallen leaves, needles, and twigs.
3. Create horizontal space between shrubs and trees.
4. Create vertical gaps between trees, shrubs, and grasses.

Spacing plants and trees

By creating space between trees and shrubs, the spread of fire can be slowed or stopped. These spaces are vertical (up and down) and horizontal (side to side). To maintain safe vertical space, remove any tree branches less than 6 feet from the ground. In areas prone to wildfire, bushes growing near tree canopies need three times their height before the lowest tree branches to prevent fire from spreading. For example, a 4-foot shrub would need to be at least 12 feet away from the closest tree’s lowest branch to be fire safe.

Horizontal spacing is a function of slope: 

• Areas that are flat or with slopes less than 20% can allow trees to be 10 feet apart. Shrubs should be two times their height apart. So, 4-foot shrubs should be 8 feet apart to be safe. 
• Slopes of 20 to 40% require shrubs to be four times their height apart, and trees need 20-foot spacing. 
• When working with steeper slopes, trees should be 30-feet apart, and shrubs need to be six times their height apart.

What about all that mulch?

Nearly everything you read in The Daily Garden reminds you of the benefits provided by mulch: moisture retention, weed reduction, temperature stability, reduced soil compaction, and so on. But what about flammability? Does all that groundcover create a path for fire? Luckily for us, a group of fire and gardening professionals got together in Nevada to test various types of mulch. I have listed what they learned below, worst to safest. In each case, the mulch was 2- to 3-inches deep unless stated otherwise:

• Shredded rubber burns the hottest at 630°F and flames the highest (over 3 feet).
• Pine needles spread fire the second-fastest.
• Shredded western red cedar, also known as Gorilla hair, spreads the fastest, at nearly 50 feet per minute, at 380°F, with one-foot flames and many embers.
• Medium pine bark nuggets spread more slowly with moderate flames.
• Tahoe chips, which consist of wood chips, pine needles, and other plant biomass from tree chipping, spreads moderately fast with medium-sized flames.
• Tahoe chips treated with fire retardant only slow the spread of fire by 5 to 10 minutes.
• Tahoe chips applied in a single layer burn at the lowest temperatures and spread the slowest, with the lowest flame height.
• Composted wood chips were the only material that did not “demonstrate active flaming combustion” with only “incidental flaming with smoldering”; spread less than 0.3 feet per minute.

Use fire-resistant plants

We all know that green plants burn more slowly than dead, dry plants. But there are no fire-resistant plants. If it gets hot enough, anything can burn. You can help keep your home safe by planting low-growing, high-moisture plants closest to your home. Succulents probably come to mind.

​Keep your plants green and healthy, and move flammables away from your home. 

Above all else, in case of fire: GET OUT AND STAY OUT. 

Everything else is temporary.

Our lovely fall colors are caused by a deciduous tree’s inability to maintain chlorophyll levels within its leaves. Chlorophyll, being green and abundant most of the time, masks the other colors that are alway present within a leaf. Shorter days and cooler temperatures trigger the tree to form a layer of cork at the base of each leaf, blocking the flow of water and nutrients and interfering with the leaf’s ability to produce chlorophyll. Eventually, the other colors can shine through. The veins of a leaf are the last part to turn color because it is the last place nutrients were available.

The Calvin cycle describes what happens to light energy after it has been absorbed into a leaf.

Put on your steampunk magnifying glasses because, today, we are going deep into the molecular level of leaves to learn how they make energy from sunlight.

Also known as the Calvin-Benson cycle, Melvin Calvin won a Nobel Prize in Chemistry for figuring this out. That was in 1961. Until Melvin’s research was complete, everyone thought that photosynthesis consisted of chlorophyll interacting directly with carbon dioxide to create edible organics (sugars) for plants. Instead, his research taught us that light energy causes chlorophyll to trigger plants to produce those organic compounds for themselves!

So, how does photosynthesis work?

Photosynthesis

Photosynthesis occurs in two steps. The first step is the light dependent reaction. This is when the sunlight is absorbed and transformed. To do this, electrons are torn from water molecules, creating oxygen as a waste product. When this happens, hydrogen (H) is released and used to create two compounds: nicotinamide adenine dinucleotide phosphate (NADPH) and adenosine triphosphate (ATP). The second stage of photosynthesis is the light independent reaction, or the Calvin cycle. This is when the ATP is converted into glucose.

Calvin cycle

​Each stage of the Calvin cycle has its own enzyme. Enzymes are chemical catalysts that trigger change. After light energy has entered a plant through the stoma and been converted into ATP and NADPH, the light-independent (or ‘dark’) aspect of photosynthesis can begin. There are four stages to the Calvin cycle:

1. Carbon fixation - a five-carbon enzyme molecule (RuBisCO*) snags a molecule of carbon dioxide (CO2) and turns into a six-carbon molecule
2. Reduction - The six-carbon molecule is split in half by an enzyme, using energy from ATP and NADPH molecules; one half becomes a sugar phosphate molecule, which is later combined to make starch and sucrose; the other half moves on to the next step
3. Regeneration - Again using energy from ATP and NADPH, the three-carbon molecule becomes a five-carbon molecule and the process starts over

​For your chemistry buffs, here's the equation and a graphic:

In the illustration above, atoms are represented as black (carbon), white (hydrogen) red (oxygen) and pink (phosphorus).
​
For the rest of us, try this story for a more memorable form:

​Rubio marries Connie. Connie has twins. One twin becomes a cook. The other works the family business and marries a girl just like mom. And they have twins. And so it goes….

​Factors that interrupt the Calvin cycle

Any interruption in photosynthesis leads to chlorosis, or yellowing. Chlorosis can be the result of insufficient light (epinasty), disease, a lack of mycorrhizae, or sunburn. Other factors that interrupt the Calvin cycle include:

• excessive heat
• overspray of herbicides and other chemicals
• soil pH - too much acidity
• insufficient magnesium uptake - it may be present in your soil, but other factors can limit uptake

If you see chlorosis, it means your plant is starving. By learning about the Calvin cycle, you may be better equipped to figure out what is wrong with your plants. Get growing!


* RuBisCO - ribulose bisphosphate carboxylase/oxygenase; believed to be the most abundant enzyme on Earth (Wikipedia)

Hummingbirds

We may love to see hummingbirds flitting through the garden, but you should be aware that hummingbirds may carry flower mites. Flower mites are tiny, nectar stealing pests that run up a hummingbird’s beak as it feeds. Grabbing ahold of the hummingbird’s nostrils, flower mites then go for a wild ride in hopes of reaching a new food source. When the hummingbird stops to feed at a different flower, the mite runs down the hummingbird’s beak to gorge on as much nectar as it can before hopping another ride to yet another flower.

Honey bees

Moving in the opposite direction, it has recently been discovered that varroa mites, the bane of honey bees, are phoretic. These devastating parasites of the honey industry lie in wait for unsuspecting honey bees to visit a flower. As the bee collects nectar and pollen, varroa mites catch a ride that ultimately takes them to the hive. These parasites suck the life fluids from developing and adult bees. These pests also carry viruses that infect honey bees. Varroa mite infestations can kill an entire hive, if left untreated. Varroa mites are just one aspect of the global problem of colony collapse disorder.

Ground bees

Male ground bees are seduced by blister beetle larvae into carrying them to female ground beetles, phoresy style. Blister beetle larvae emit a pheromone that is similar to the perfume used by female blister beetles to attract males. When male ground bees approach, the blister beetle larvae attach themselves to the male bees. After recovering from their disappointment, the male bees continue their search for a female. When she is found, the male bee blindly does his business as the blister beetle larva moves to the female bee. When she returns to her nesting area, the larva jumps off and begins feeding on everything it can - nest, provisions, and eggs.

Succession planting takes a long term view of garden usage. Instead of simply planting whatever seed packets looked best in the garden catalog, successful gardeners look at the same space over time to see what can be planted after the current crop.

Benefits of succession planting

Succession planting makes efficient use of fertile ground by leap-frogging plants and crops for a continuous harvest. This eliminates the deluge of every plant reaching harvestable size within the same week. That’s great if you’re putting up tomato sauce, but it can be a bit much when talking about 20 Romaine plants! By changing the life stage and/or plant type in any given bed, the odds of total crop failure due to pests or disease are reduced. Growing plants at various life stages in the same place also cuts back on the amount of real estate available to weeds. Finally, planting fast-growing crops with slow-growing crops makes good use of soil that might have otherwise gone fallow.

Different methods of succession planting 

In its simplest form, succession planting refers to following one crop with another crop. This is generally done as the weather changes, following a summer crop with a cool season crop. But there is more to it than that. In addition to consecutive plantings, there is also staggered planting, intercropping, and varietal planting.

Varietal planting

Varietal planting means installing different varieties of the same plant in the same place, at the same time. These varieties have different maturity dates, providing a continuous harvest. You can fine tune your varietal plantings by taking note of days to maturity and mature size information on seed packets. You may be able to start with an early maturing variety, followed by a mid-season harvest, then a late-season harvest. You may even be able to squeeze in yet another early harvest at the end.

Staggered planting 

​Staggered planting refers to planting seeds of the same plant in the same area, but on different days. This extends the harvest season, providing a continuous, smaller harvest of the same plant. Staggered planting is best suited for lettuce, spinach, radishes, beets, carrots, and peas. For most of these crops, you can start a new set of seeds every week or two, for the best possible production.

Intercropping

Intercropping puts different crops together in the same place, at the same time. This allows gardeners to make use of soil resources that might have gone unused with a single crop. It also increases biodiversity, reducing potential pest and disease problems. One example of intercropping is the Three Sisters Method of growing beans, corn and squash together. Intercropping is the scientific basis behind the Companion Planting craze. I’m sorry, but there are no magic pairings of plants that “like” each other. There are structural and developmental needs of different plants that either support one another or don’t interfere with each other, while growing in the same space. Basic intercropping pairings include:

• climbing plants with tall, sturdy plants
• shade-loving plants under large-leafed sun lovers
• root crop plants with plants that put most of their structure aboveground

Planning for succession planting

Your can take advantage of the benefits of succession planting, simply by growing two seasonally different crops in the same bed. As one crop is winding down, the next season’s crop can be getting started. Or, you can get really in-depth into this concept by investing some planning time. To make the most out of your garden space with succession planting, you will need to know the following:

• length of your growing season
• seasonal temperature ranges
• soil makeup and structure
• mature plant sizes, above and below ground
• irrigation and nutrient needs of each plant
• days to maturity for each plant

The next step is to collect information on all the plants you want to grow. You can do this with pencil and paper, in a spreadsheet, or you can clean off a big table and start moving seed packets around into different groups until you reach what looks like a good plan.

Do yourself and your garden a favor and take note of what works and what doesn’t. Just remember, every garden is different, every year is different, and sometimes we are simply unlucky when it comes to temperature extremes, pest infestations, and nutrient deficiencies. Succession planting can offset some of those problems.

Clubroot is not the newest bar in town; it is a disease of many fall and winter crops.

Clubroot, or club root, is caused by an imported plant parasite that grows inside plant cells. It used to be classified as a slime mold but is now in an entirely different category called Phytomyxea. This pathogen is called Plasmodiophora brassicae, but don’t let the name scare you off from learning about it. The brassicae part of the name tells you which plants are susceptible: the cabbage family. The Plasmodiophora part of the name tells us these are mouthless, amoeba-like plant parasites.

Which plants are affected by clubroot?

Clubroot occurs in nearly all members of the brassica family, including broccoli, Brussels sprouts, cabbages, cauliflower, radishes, and turnips are susceptible. Alyssum, mustard, nasturtium, and wallflowers can also become infected.