Leafhoppers enjoy many of the same plants that we do. In addition to many woody ornamentals,  such as boxwood, local leafhopper species love to feed on sweet potatoes, squash, beans, horseradish, cucumbers, corn, melons, blueberries, grapes, and beets, just to name a few! Since leafhoppers can carry diseases with them, they put many plants at risk.

Summer squash vs. winter squash
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All squash plants are cucurbits, along with gourds and cucumbers. Squashes are classified as either summer or winter varieties. The main difference between summer squash and winter squash is when it is eaten. Summer squashes, which are generally eaten immature, have thin, tender skins, while winter squashes have hard skins that allow them to be stored for longer periods of time. Common winter squashes include pumpkins, Hubbard, acorn, and butternut squash.

Types of summer squash

There are two main types of summer squash: zucchini and yellow, but these are divided up into several different varieties:

• green zucchini - the classic
• yellow (or golden) zucchini - no tapering, straight cylinder
• Romanesco zucchini - stays tender even when it reaches horse leg proportions
• straightneck yellow - tapers at the stem end
• crookneck yellow - tapers at the stem end with a crook
• pattypan - scalloped disks
• cousa - shorter and stubbier than zucchini
• zephyr - a cross between yellow crookneck and yellow acorn
• eight ball - a spherical zucchini

How to grow summer squash

Summer squash prefers a sunny, well drained area, with a pH of 5.5 to 6.5, so acidification may be needed. Squash seeds are very large and should be planted about an inch deep in May and June. [The basic rule of thumb for the planting depth for any seed is to use the longest length measurement of the seed and bury it that deep.] Keep the soil moist until germination occurs, but do not let it stay soggy or damping off disease may kill your squash seedlings. Squash plants generally do not take kindly to transplanting, so it is better to plant the seeds where you want them in the first place.

​These plants will take up some space, though they can be grown in containers, towers, and straw bales, and they love raised beds! Squash is a traditional member of the Three Sisters Method of growing beans and corn in a mutually beneficial garden design. Generally, winter squash vines can get very long, while most summer squashes have more of a mounding growth, though this isn’t always the case. Be sure to read the seed packet for variety-specific information. Squash is a relatively light feeder, so fertilizer is rarely needed. These plants generally get enough nitrogen from the soil. Too much nitrogen will encourage plenty of leaves but very little fruit. Of course, adding some aged compost around the plants as mulch certainly wouldn’t hurt!

Summer squash pests and diseases

If you look at a list of all the pests and diseases that affect summer squash, you’d wonder how these plants survive at all. But they do. In fact, they thrive! But it’s always a good idea to know what might happen, so you can nip it in the proverbial bud before things get out of hand. Common summer squash pests include aphids, armyworms, cutworms, redhumped caterpillars, leaf miners, loopers, cucumber beetles, nematodes, grasshoppers, slugs and snails, stinkbugs, wireworms, earwigs, and various beetles. Squash bugs are generally your biggest threat and they make themselves known in July in the Bay Area. As far as I know, squash vine borers have not yet made their way over the Rockies, but be forewarned! Row covers go a long way toward protecting your summer squash plants against these pests. Summer squash diseases can categorized by the pathogen:

• Fungal - verticillium wilt, powdery mildew, Fusarium crown and foot rot, and belly rot
• Bacterial - angular leafspot
• Viral - cucurbit yellow stunting disorder (spread by whiteflies), squash mosaic, zucchini yellow mosaic, and curly top

Environmental conditions, such as irregular watering, can cause blossom end rot, bitter fruit, and blossom drop. Poor pollination can also be a problem. Despite all these threats, summer squash plants nearly always produce an astounding amount of food.

Harvesting summer squash

Squash plants can run amok and get away from you. Everyone has a story of the monstrous zucchini they swore wasn’t there the day before. It happens. When it does, stuff it with sausage and onions, or make some chocolate zucchini cake. One nice thing about summer squash is that it can be harvested at any stage in its development. Simply cut the stem and enjoy the fruits of your labor! Once you’ve harvested a summer squash, you can add it to stir fry, salads, soups, stews, or just nibble on it while reading a good book. Odds are, another one will be ready to harvest in a day or two. Summer squash is particularly sensitive to ethylene gas, so you will want to keep them away from bananas and other ripening fruits.

One seed and a little water can provide you with a surprising amount of fresh food. Plant one today and see what happens!

Marjoram is the soft-spoken cousin of oregano.

Marjoram is a tender perennial herb that can do well on a window sill, in a tower or other container, or tucked away in a quiet corner of the garden. These plants also make nice rock garden additions and they look (and smell) lovely next to walkways and in parterres. The Greeks and Romans used marjoram as a symbol of happiness, and it certainly puts a smile on my face whenever it turns up in my foodscape.

Uses for marjoram

Marjoram leaves have been a culinary herb for a very long time. It is slightly more mild and piney than its boisterous cousin, oregano. Marjoram is used to make herbes de Provence and za’atar. Marjoram also attracts many beneficial insects, including butterflies and bees, with its tiny white, pink, and lavender flowers.

​An herb by any other name

Marjoram (Origanum majorana) has been around long enough to have several names to differentiate it from oregano (Origanum vulgare), including sweet marjoram and knotted marjoram. Oregano is also known as wild marjoram. Other varieties of marjoram include:

• pot marjoram, or Cretan oregano (Origanum onites)
• hardy or French marjoram, which is a cross between marjoram and oregano
• showy marjoram, or showy oregano (Origanum pulchellum)

Growing marjoram​

Marjoram is best started in pots. Seeds should be covered only lightly with soil. Keep the soil moist until seeds germinate, being careful not to wash them into a corner of the pot with miniature floods of water. Marjoram prefers full sunlight and loose soil. Plants should be hardened off before installing outside, and spaced 18 inches apart. Marjoram and oregano are both members of the mint family. As such, they tend to spread underground using rhizomes. This makes them a good ground cover plant, as well. Marjoram has semi-woody stems that lend themselves nicely to cascading out of hanging pots, or as a low shrub. While technically an evergreen, cold temperatures will cause them to lose their leaves and frost will kill the above-ground portion. One way to protect your plants and keep the garden attractive in winter is to cut the plants back to ground level and cover with a winter blanket of mulch. Come spring, those delicious new leaves will come right back for another year. Luckily for those of us in the Bay Area, marjoram prefers alkaline soil, which we have in abundance. Marjoram never needs fertilizer when grown in the ground, and it rarely needs watering once established.

Marjoram pests and diseases

I have found whiteflies and spider mites to be the biggest problems for marjoram. Those tiny sap suckers leave behind speckled, bleached out leaves that don’t look at all appetizing. You can fight back with a spray bottle filled with soapy water or diluted horticultural oil. (Dormant oil is too heavy.) Aphids, cutworms, mealybugs, and thrips may also try feasting on your marjoram plants, but a forceful spray of water can every morning can usually displace most of these pests. Though rarely affected, fungal diseases such as dodder, damping off, downy mildews, powdery mildew, rust, and botrytis blight (gray mold), can occur on marjoram.


How to harvest marjoram

Just as your marjoram plants begin to flower, snip off the upper portions and hang them in a shady spot to dry. Garages work well. Guest room closets work even better. I like to believe that the gentle aroma helps guests enjoy a restful sleep. That might just be me.

Try adding marjoram to your garden or landscape today for many years of fragrant, delicious beauty.

Flies swarmed over my ornamental shrub and I was confused. One expects to see flies collecting around, well, around less desirable resting spots. I have dogs and chickens, so there were plenty of other, more odiferous opportunities, but the flies clearly were more interested in my shrub. What was going on? Let’s find out.

Crane flies, dragonflies, butterflies, fruit flies, whiteflies, hoverflies, you’ve heard plenty about these flying insects in the garden, but what about the lowly housefly? It turns out, houseflies (Musca domestica) are not necessarily the pests they have always been made out to be, not completely anyway.

True, nobody wants a fly landing on their food. There’s too many awful places they may have been. Those hairy legs of theirs may have been walking around in some nasty messes. You may be surprised to learn, however, that one of the most common places to find houseflies… is in the flowers of your garden.

The nature of flies

Most flying insects have four wings. Flies only have two. True flies are all members of the Diptera family. Unlike busy bees and industrious ants, most fly species are lazy. They are mostly meat eaters. They also feed on manure, rotting stuff, and even open wounds. (Ew!) What you may not know is that flies also enjoy cleansing their palettes with a sip of nectar now and then. When flies land on a flower for a sweet sip, their hairy/spiky legs collect pollen. Most of them don’t eat the stuff, or hoard it, the way bees do. It just sticks to them. When they fly to their next sipping/resting spot, the pollen goes with them and often pollinates that flower. The process continues at a surprising rate. It ends up that flies are probably one of the first pollinators of flowering plants.

Bees vs. flies as pollinators

We all know about honey bees pollinating our crops: the bees go from flower to flower, collecting nectar and pollen and they transfer the pollen to other plants, leading to pollination, fertilization, and food for us. The problem with bees, as pollinators, is exactly that - they take the pollen with them. Eventually, there is no more pollen in a particular flower. That means bees can visit a flower and not pollinate it. Flies, on the other hand, generally do not eat pollen, so there is more left behind as they move from flower to flower, looking for a place to rest and have a drink. In a study conducted by the North Central Region Plant Introduction Station (NCRPIS), it was shown that adding blue bottle flies (Calliphora sp.), along with honey bees, as pollinators, carrot production was significantly increased. Also, flies are active within a wider temperature range than honeybees.

Crops commonly pollinated by flies

There are a surprising number of crops regularly pollinated by flies, besides members of the carrot family. These include apples, raspberries, strawberries, pear, plum, cherry, peach, nectarine, blackberries, and pawpaw. There is a group, called flower flies (Syrphidae), that pollinate dozens of our food crops. One particular species of fly, Ornidia obesa, is the reason we have chocolate. Yes, I said it. Flies pollinate cocoa plants.

Flies may not pollinate as many crops as bees, but they are already a close second, and that claim is made with only minimal research. We may find they are responsible for far more pollination. That being said, flies can also carry disease. They are free to roam my garden and landscape, but my patio is draped overhead with fly paper. Simple, yet effective.

Collectively, chenopod branches are alternate (which means they take turns up a stem), the leaves have petioles (tiny stems) and are shaped like a goose’s foot; hence the name ’cheno’, which means goose, and ‘pod’ which means foot. Young leaves and stems are often covered with tiny hairs (trichomes) or a white mealy dust, a condition called farinose.

Many chenopods, such as common lambsquarters, are considered severe agricultural weeds, and the pollen from all of these plants can cause an allergic reaction for some people. Flowers generally bloom from spring through fall, but we can enjoy the benefits provided by some of the more benign varieties without adding invasives into our gardens and landscapes. Humans have been eating chenopods for over 6,000 years. Below are some of the more common chenopod edibles.

Quinoa

Quinoa (Chenopodium quinoa) has taken grocery store shelves by storm as a high-protein, gluten-free grain. Quinoa oil is also now recognized as a high quality oil. To grow your own quinoa, simply wait until summer’s scorching heat has passed, and plant seeds in rows, 1/4 inch deep. Plants will need to be thinned to 8 to 12 inches apart. Water gently, at first, to avoid washing seeds away, and you may need to protect them against birds, in spite of the seeds’ bitter saponin coating. Keep the soil moist until seedlings are well established, then they are very drought tolerant. Quinoa reseeds itself nicely.

Amaranth

Did you know that you can pop amaranth the same way you pop popcorn? It’s true! You get itty-bitty kernels, but it’s fun to watch and it tastes good. The leaves are also edible. Different varieties of amaranth work better for seed production (Amaranthus caudatus, A. cruentus, A. hypochondriacus, A. retroflexus), while others are better suited for producing leafy greens (Amaranthus cruentus, A. blitum, A. dubius, A. tricolor, A. viridis). Growing your own amaranth is pretty much the same as growing quinoa: the soil must be warm and kept moist, and seeds are only covered with a little soil.

Chenopod pests and diseases

Birds enjoy eating the seeds, but these plants continue to survive and thrive, so the damage can’t be all that significant. The same holds true for apple stem grooving virus, tobacco necrosis virus, and the cowbane mosaic virus. They try to slow these plants down, but generally cannot. 

Find a sunny spot in your garden or landscape for these colorful edibles!

Belly rot looks almost as bad as it sounds (but I couldn’t find a decent photo).

What starts as brown or black mushy areas on the underside of your melons or squashes turns dry and leathery. It won’t hurt you but can make fruits susceptible to other pests and diseases.

​Melons, squashes, and other cucurbits can all get belly rot. Belly rot is a fungal disease caused by Rhizoctonia solani. Infection occurs when the fruit is left to sit on the soil for prolonged periods, especially when moisture is present.

Symptoms of belly rot

If you see water-soaked, sunken, black, or brown spots on fruit and it is not blossom end rot, it is probably belly rot. The lesions can be tiny or cover the complete underside of a fruit. As the infection spreads, the lesions dry out and become leathery or scabby. Infected fruit should be removed and tossed in the trash.

Preventing belly rot

To prevent the spread of belly rot, avoid overhead watering and get that fruit off the ground. You can use trellising, tomato cages, children’s furniture, straw, those little plastic pizza box props, benches, colanders - anything that will allow airflow between the fruit and the soil. Improving drainage will also make this disease less likely to occur. 

Generally, the fungi that cause belly rot are everywhere, so prevention is your best bet. So check the bellies of your melons regularly!

First, we will take a cross-sectional look at a tree trunk, from the inside out:

• pith - the dark, spongy center used to carry essential nutrients
• heartwood - dead sapwood; the hardest (and most expensive) wood in the tree; usually darker than sapwood
• sapwood (xylem) - living cells that help water rise up through the plant [xylem : rise]
• cambium - living cells that produce new tissue, making the tree wider 
• bark (rhytidome) - inner (live) phloem cells, which help sap flow down, and dead cells that create a protective outer covering
• medullary rays - channels that go from the center to the edge to carry water and nutrients 

​How bark is born

Young stems of woody plants do not have bark. Instead, from the outside in, they have an epidermis (skin), cork (periderm), cortex, primary and secondary phloem, vascular cambium, primary and secondary xylem, early wood and late wood (each double ring represents one year of growth), combined with the primary and secondary xylem, and the pith. As the stem grows, the cork gets thicker, pushing the skin away from the wood. Isolated from water- and nutrient-carrying vascular tissues, these cells die and become what we recognize as bark. This tough, outer surface helps keep water in, and pests and diseases out. It also provides protection against temperature extremes and sunburn damage. [The skin of a potato, being a modified stem, is actually the cork.]

What is bark?

Bark is mostly lignin. Lignin is the material that makes trees stand up. Bark also contains tannins. Tannins are believed to inhibit decomposition. Bark is made up of two distinct parts, the living phloem and the dead periderm. Phloem is the vascular tissue responsible for helping sap flow downward throughout the plant. The periderm is made up of cork (phellem), cork cambium (phellogen), phelloderm, and the cortex. Within the periderm are large spaces that allow gases to move from the tree to the atmosphere and vice versa. These spaces are called lenticels. As a tree grows, and inner layers are pushed outward, the lenticels create unique markings that are used in tree identification. For example, silver birch trees (below) have distinct horizontal lines which are the lenticels.

When bark is severely damaged by mechanical injury, insect or bird feeding, or girdling, tree death can occur.

Types of bark

Bark comes in many shapes, colors and thicknesses. Bark is generally described by its texture. It can be smooth (American beech), scaly (black cherry), plated (black birch), warty, shaggy, papery (paper birch), furrowed, or fibrous. They ridges can also be useful when identifying a tree. Bark may form vertical strips (red maple), ridges (white ash), ridges that are broken horizontally (white oak), or it may be uninterrupted ridges (red oak).

Did you know that cinnamon is actually the bark of trees?

And those little plugs that protect your wine are bark from the Quercus suber (cork oak) tree.

Braconid wasps are tiny heroes of the garden, though rarely seen.

The list of edibles protected by braconid wasps is too long to include here, but it would include grapes, peaches, nectarines, apricots, tomatoes, apples, prunes, plums, broccoli, rutabagas, turnips, and cabbage, just to name a few.

Braconid wasp identification

​There are over 12,000 different named braconid wasp species, worldwide, with another 40,000 or so, yet to be identified. Most are dark brown or black with reddish accents. It is estimated that there are 1,700 different braconid wasps in North America and they are all stingless. Braconid wasps can be as small as 1/13 of an inch long, or as big as 5/8 of an inch. If you can get one to hold still while you go find a hand lens, you would be able to see that these tiny wasps have antennas with 16 or more segments! What you are more likely to see are their oblong, white or yellow eggs sticking out of a host insect.

Gray mold is what appears overnight on your strawberries. 
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Where did it come from? And how did it happen so fast? Strawberries can go from nearly perfect to practically inedible in the blink of an eye. And it is called gray mold.

Spring and summer fogs and dew can leave behind just enough moisture to create breeding grounds for several different bacteria and fungi. While there is a specific disease called black spot, there are other bacterial and fungal diseases that can cause black spots, including citrus blast, common leaf spot, bacterial spot, anthracnose, bacterial speck, and entosporium leaf spot. Black spot mostly attacks roses, but its presence can indicate potential other problems in the garden or landscape.

What are the black spots on my leaves?

Black spots on leaves, fruit, canes, stems, and twigs are areas where a pathogen is breeding and feeding on plant tissue. These black spots are generally round because the infection begins at one point and spreads out equally in all directions. The spots have perforated edges and can reach one-half inch in diameter. As the area of dead tissue expands even larger, it can take on many different shapes. There may be a yellow halo around these leaf spots and yellowing in the surrounding plant tissue.

​Black spot: the disease

The black spot disease is caused by a fungus called Diplocarpon rosae. These fungi spread through rain and sprinkler splash, wind, ants, and aphids, to tender new growth. This disease usually spreads from lower leaves, moving upward. Garden tools can also spread the disease to other plants, so be sure to sanitize your tools with a household cleaner, such as Lysol, after each cut when working with a potentially infected plant.

This disease is not to be confused with blackspot, or Ascochyta blight, caused by Ascochyta rabiei. That particular fungal disease causes brown lesions with black dots, most commonly seen on chickpeas.

Black spot treatment

Once a leaf is infected, there isn’t anything you can do for it except remove it from the plant and throw it in the trash. Antifungal sprays, such as Bordeaux mixture, can be used to prevent future infection and at the first sign of the disease. Sulfur or diluted neem oil can also be used. Treatments will need to be repeated every 7 to 10 days for as long as temperatures are between 75 to 90 °F.

Preventing black spots
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As usual, prevention is a lot easier (and more effective) than treatment. These tips can go a long way toward preventing the problem of black spot in the first place:

• Remove fallen leaves
• Avoid overhead watering
• Spray new growth with fixed copper or Bordeaux mixture
• Irrigate in early morning to give plant surfaces time to dry out (spores need 7 hours of moisture to reproduce)
• Provide ample space between susceptible plants
• Prune for better airflow
• Apply sticky barriers to block ants from protecting aphids
• Spray aphids off plants early in the morning, using a garden hose, or knock them off with a soft-bristled brush

Next time you are out in the garden, see if you can spot any telltale signs of black spot on your plants.

Shade tree decline, or shade tree disorder, is a term used to describe branch and twig dieback in the crown of a tree. These trees are not affected by pests or disease, per se, but they are sick.

In winter, most deciduous trees are bare. By late spring, a thick blanket of sugar-producing machinery covers those trees. Every leaf surface should be cranking out energy as fast as it can. In recent years, especially in heavily populated areas, somewhat healthy-looking trees tend to be a bit thin on top. This thinning is not a hormonal problem treatable with hair tonic. Shade tree decline is a serious problem. Those trees are dying.

Drought (or lack of proper irrigation) is the number one cause of shade tree decline, but there are other causes. And ornamental trees are not the only victims. Canada’s sugar maple trees have been exhibiting shade tree decline for decades. That decline is due to air pollution blowing northward along our Eastern seaboard. [My sincere apologies, Canada.] There are many other causes (and few solutions) to the problem of shade tree decline.

Symptoms of shade tree decline

Symptoms of shade tree decline appear gradually. Like the frog in the proverbial pot, we often don’t notice the damage until it is severe. Initial signs of shade tree decline include:

• Reduced new growth
• Die-off of new twig and leaf buds
• Leaves are smaller and fewer
• Premature fall color change
• Early leaf drop

Later symptoms include:

• Thinning of the crown
• Excessive seed production
• Dieback of larger limbs and branches
• Increased sucker growth

These are all signs that the tree knows it is dying. It is frantically putting what little energy it has left into the next generation. Most trees affected by shade tree decline die within a few years.

What causes shade tree decline?

Imagine being pummeled all day, every day. Professional boxers do it, but they have strict nutritional support, medical teams, and proper hydration. Drought, pollution, and injuries have plagued our trees for many years, but most never noticed. Some of the more common injuries include the following:

• Extensive bark damage from lawnmowers and weedwackers
• Herbicides and other chemical damage
• Soil infertility
• Soil compaction
• Extreme temperature changes
• Flooding or changes in the water table
• Root damage due to rototilling and digging
• Girdling by tree supports left in place too long
• Sprinkler misplacement (never let the spray hit tree trunks)

The downside of shade tree decline

Trees are an investment in the future. They cost money and take time to grow. They also prevent erosion, provide shade and food, store carbon, create the oxygen we breathe, and filter pollutants out of the air. They provide habitat and food for many other living things, promoting biodiversity. As a tree begins to suffer shade tree decline, it becomes less able to defend itself against pests and diseases, becoming more likely to suffer sunburn damage, providing easy entry to borers and other insect pests.

The bigger problem

The Carnegie Institute for Science reported that California lost more than 58 million large trees between 2011 and 2015. Even when heavy rains appear, the damage has already occurred, and tens of millions more trees will die. The strain on the trees has been too much. Dead and dying trees harbor pests and diseases in epidemic proportions. The large-scale die-off of trees also makes it easier for invasive plants to get established. And sick trees can be fire hazards.

Preventing shade tree decline

Prevention is much easier and more likely to succeed than treatment. You can help your trees stay healthy by recreating the conditions they evolved in to prevent shade tree decline.

These tips can help you protect your trees against shade tree decline:

• Prune shade-loving trees to keep them in the shade of a more heat-tolerant tree.
• Coil a soaker hose in a spiral around the tree trunk, starting a few inches from the base, ending at the drip line, and watering deeply regularly during summer.
• Fertilize regularly and only as needed, depending on lab-based soil test results.
• Mulch under trees, keeping the mulch six to eight inches from the trunk.
• Avoid overspray of herbicides and other chemicals.
• Install trees a safe distance from concrete surfaces that produce heat islands.
• Plant trees in soil with a suitable pH.
• Remove tree supports when they are no longer needed.
• Install footpaths around trees to reduce soil compaction.

Treating shade tree decline

Prospects for an affected tree are not good. The damage has already occurred. Even the most diligent care may not be enough. If you are determined to try, these actions may save your tree or help it to survive a little longer:

• Fertilize the tree in spring.
• Prune out all dead branches and twigs.
• Mulch.
• Provide extra water throughout the growing season.

How to irrigate trees

Most tree roots are in the top 12 to 18 inches of soil. When these roots get too dried out for too long, they die. Fewer roots reduce the amount of water available to the tree for life processes and cooling (and growing new roots). Frequent, light watering encourages shallow root development. Deeper roots are less likely to be damaged by the elements and may access groundwater. 

Properly irrigating trees means getting the water to a depth of at least five to seven inches every three or four days during the peak of summer. Before we knew better, we used to plant trees in bowl-shaped depressions we would fill with water. Sounds good, but it’s a bad idea. This practice leads to crown rot and several other fungal diseases. Better methods include soaker hoses and irrigation rings. Irrigation rings can be mechanical devices or nothing more than trenches dug around trees at the drip line. Fill the irrigation trench with water every few days during the peak of summer, and your trees will thank you.

Selecting the right trees

If it is too late to save your tree, invest in a reputable arborist for professional removal. Trees can be deadly. Seriously. Then, use the following information to select trees better suited to your microclimate:

• Get an inexpensive, lab-based soil test.
• Identify your USDA Hardiness Zone.
• Select trees suited to your soil structure and microclimate.
• Plant trees where they can reach full size (big trees in small spaces are rarely healthy).
• Plant trees where they will get the correct sun exposure.
• Irrigate trees properly.

Fighting Mother Nature is a full-time job, and it’s mostly a waste of time. Rather than setting ourselves up for tons of maintenance in a never-ending battle, put the things that occur naturally in your landscape to work for you and your trees.

How wax beans grow

Beans are self-pollinating annuals. These plants are fun and rewarding to grow. They grow quickly enough to work well as a children’s activity, reaching maturity in only 60 days. What’s really fun about these plants is that they can be grown pretty much anywhere: on a windowsill, in a container, in a straw bale, and in partial shade. Of course, they prefer sunny raised beds or traditional garden rows, but, the point is, these plants are EASY.  Like other legumes, wax beans are able to ‘fix’ atmospheric nitrogen, making it available not only to themselves, but to nearby plants. Of course, this only works until the plant starts producing seeds, then the free lunch is over.

How to grow wax beans 

Like other beans, wax bean seeds are mostly endosperm (plant food). Plant seeds one inch deep and 2 to 4 inches apart. If you grow bush beans (not the canned barbecue product), your plants will get 18 to 24 inches tall and about a foot wide, so thin accordingly. Pole beans, however, can be trained up trellising, fences, lattice, sunflowers, trees, pretty much anything they can wrap their tendrils around, without thinning. They can also be used in the traditional Three Sisters Method, with corn and squash. Trellising pole beans on something that goes over your head looks really nice, with ripe beans hanging down, from overhead. It’s makes picking easy, too! Some people say that planting marigolds nearby can be a problem, claiming that they interrupt the nitrogen-fixing capabilities of legumes, such as peas and beans, but I don’t know if this is true.

Wax bean pests and diseases

When it comes to bean pests, it’s all the usual culprits: cutworms, bagrada bugs, cucumber beetles, weevils, thrips, wireworms, leaf miners, and dried fruit beetles. As delicious as fresh wax beans are, it’s no wonder so many critters are after your harvest. Bindweed can also choke out your bean plants. Common wax bean diseases include anthracnose, bean mosaic, and fusarium wilt. Wax beans should not be planted near soybeans to reduce the likelihood of stem blight.

Angular leafspot is a bacterial disease that affects strawberries, cucumbers, melons, squash, and spinach.
 
There are several different angular leafspot (ALS) diseases, depending on the host plant and the pathogen that causes it:

• cucurbits (Pseudomonas syringae pv. lachrymans)
• spinach (Pseudomonas syringae pv. spiniciae)
• strawberries (Xanthomonas fragariae)

 
There is also an ALS variety that attacks common and snap beans. This disease can also affect cotton.

Cucumber beetle identification
​
Cucumber beetles are relatively easy to identify. They are small, only one-quarter of an inch long, and they have shiny black heads. The larvae are yellowish with a dark head. Other identifying marks, by species, include:

• Western spotted cucumber beetle (Diabrotica undecimpunctata undecimpunctata) - adult beetles are bright greenish-yellow with 12 black spots. They are sometimes confused with ladybugs, but ladybugs have short, stubby antennae, while cucumber beetles have thin antennae that can be up to 1/4 inch long.
• Western striped cucumber beetle (Acalymma trivittatum) - three black stripes and an orange thorax (these are seen less often in San Jose, California)
• Banded cucumber beetle (Diabrotica balteata) - rarely seen outside of the southern U.S. regions

Cucumber beetle damage

Adult beetles overwinter in the soil and lay their bright orange eggs at the base of host plants. When these eggs hatch, ravenous larvae start feeding on plant roots. Adults will feed on roots, blossoms, leaves, and plant crowns, along with fruit, as they feed. This is especially true for tender, new growth. Cucumber beetles can easily kill seedlings, and they feed on far more than just your cucumbers. Other favorite plants are corn, beans, lentils, roses, and grasses, along with your melon and squash plants. They are also attracted to ripening stone fruit. Holes in leaves may be the first obvious sign of infestation. Cucumber beetles can also carry squash mosaic virus (for up to 20 days after feeding on infected fruit), and bacterial wilt, a fatal cucurbit disease.

Controlling cucumber beetles

Cucumber beetles are difficult to control. Parasitic tachinid wasps provide some assistance, so avoid broad spectrum pesticides, which will kill off your helpers along with the pests. Cucumber beetles prefer cool, moist places, such as under your squash or melon plants after they have been watered. That makes it the best time to look for these pests and squish them as soon as you see them. They can bite, so wearing gloves is a good idea. Since cucumber beetles can fly, battling them is an ongoing process. Regular monitoring is your best defense.

Overspray, drift, or carryover occurs when herbicide from neighboring property reach your plants. It rarely ends well, and it can make for strained relations. And sometimes you do it to yourself.

Those pesky weeds coming up through the patio blocks or on pathways are a pain to dig out. One quick spray and they are gone. Right? Wrong. But there is a slightly easier way, so read on!

Very often, overspray is accidental. A quick breeze blows in, the temperature shifts, or your happy canine wags through the garden. In other cases, overspray is due to thoughtlessness, ignorance, or vandalism. From your point of view, it makes no sense. One day, your plants are thriving. The next day, something is wrong.

Symptoms of herbicide damage

The symptoms of herbicide damage vary, depending on the chemical used. Broadleaf weed killers cause leaves to twist and cup. New leaves narrow. Also, the roots of annual plants will come closer to the surface than is good for them. These herbicides will, as advertised, cause grasses to turn yellow and die. Non-selective herbicide overspray will cause chlorosis, poor health, dieback, and death. Other symptoms of herbicide overspray include leaves turning purple, stem dieback, and leaf mottling and spots. These symptoms can indicate other problems, too, so diagnosing overspray can be challenging.

How overspray occurs

Sometimes the best indicator of a problem is seeing your neighbor applying chemicals the day before. Most herbicides are sprays. And that vapor can spread to areas unintentionally, especially if there is a breeze, low humidity, or high temperatures. Herbicides can travel for miles on the wind. And those convenient handheld spray bottles look safe, don’t they? But, when you squeeze that handle, it is too easy for the spray to bounce off your intended target, the soil, or your shoe and land elsewhere. That contaminated shoe can now carry the herbicide to new plants. After an intentional application, the surrounding soil also contains herbicides. This soil can be scattered, tracked on the sole of a shoe, moved around on gardening tools, or carried on a breeze to places where herbicides are not wanted.

Preventing overspray

There are several ways you can prevent overspray from damaging or killing plants you never meant to harm:

• ALWAYS FOLLOW PACKAGE DIRECTIONS EXACTLY. EVERY TIME. NO MATTER WHAT.
• Communicate with neighbors about what chemicals are being used, when, and how.
• Identify plants sensitive to overspray and use less damaging herbicides (or none at all) in those areas.
• Leave buffer zones between treated and untreated areas.
• Do not apply herbicides while the wind is blowing.
• Do not spray if temperatures are unstable. Thermals can carry chemicals the same way the wind does.
• Use low-pressure nozzles to reduce the number of tiny droplets that are more likely to travel.

Treating victims of overspray

Large perennial plants can often be saved from the effects of overspray if treated soon enough. The chemicals move more slowly through the vascular tissue of these larger plants. Remove any leaves that have come in contact with an herbicide to halt the spread of the chemical. Rinse plants off with a hose and water them well. Of course, the water that comes off the plant will contain herbicides, which can then spread to new locations. [Oh, what a tangled web we weave…] 

Anyway, watering the plant will help to dilute the chemicals. These plants will require special care for at least a year. Left untreated, they will eventually die. Dispose of tender annuals and edibles affected by overspray in the trash (not the compost pile). Even though you might be able to keep these plants alive, do you want those herbicides in your food?

Finally, you are legally liable for damage caused by overspray, even when unintentional.

As for those pesky sidewalk weeds, grab a sharp knife or screwdriver and cut them off at ground level. Then, pour a liberal amount of vinegar over the area. It may not kill the root, but it will take the plant a lot longer to return if it does at all.

 Tomatillo plants are free spirits and they make delicious salsa verde!

Unlike most other agricultural plants, tomatillo plants refuse to be hybridized. This is pretty surprising, since recent research has shown that tomatillos have been around for 52 million years! They have retained their wild nature while still providing us with an easy to grow edible plant. These members of the nightshade family (Solanaceae), are cousin to tomatoes, potatoes, peppers, eggplant, and tobacco. As such, you should not eat any part of the plant other than the fruit.

Tomatillo description

Tomatillo fruits are greenish and sticky. They come wrapped in their own natural paper husks. The plants, being wild by nature, can take on a variety of shapes and sizes, but they tend to be low-growing, sprawling plants. If you want something really unique, you can even find purple tomatillos! Tomatillos are one type of ground cherry, but there are many others.

How to grow tomatillos

Native to Mexico, tomatillos (Physalis philadelphica), also known as Mexican husk tomatoes, prefer bright, sunny locations and they are somewhat drought tolerant. They grow best in nutrient rich soil with a neutral pH. Adding compost to the bed before planting will help give your tomatillos a head start. The plants grow quickly, but they take a long time to produce fruit (60 to 80 days). Tomatillos are not self-fertilizing, so you will need multiple plants to get a crop. Seeds should be planted 1/8 to 1/4 inch deep. Tomatillos can be grown in large containers (at least 5 gallons) but they need more sunlight than a window garden can provide. Like peppers, tomatillo seeds need warm temperatures to germinate.

If you buy tomatillo seedlings, plant two-thirds of the stem below ground, as you would for tomatoes. All those nodes will covert to root tissue, helping your new plants get a better start and produce a bigger harvest. Place mature plants three feet apart and provide support with trellising or tomato cages. Like tomatoes, you will want to keep the soil around your tomatillos moist, but not soggy. Mulching can reduce evaporation and competition from weeds. It also stabilizes soil temperatures.

Tomatillo pests and diseases

Being relatively wild, tomatillos are pretty rugged. Fungal diseases, such as powdery mildew, can occur if plants are left to sprawl on the ground, which is why providing support is a good idea. Flea beetles may also chew holes in the fruit.

Harvesting and storing tomatillos

Tomatillos stay greenish, so color will not tell you when it is time to harvest your tomatillo crop. Instead, watch to see when the fruit has filled its husk to bursting. If the fruit is left to ripen further, it will turn yellow or purple, but it won’t taste as good. Once your tomatillos are picked, you can store them in a paper bag in the refrigerator for 2 or 3 weeks, or you can make your own salsa verde and do some canning!

The evil side of tendrils

Not all garden plants mean well by their neighbors. In fact, it’s pretty much a battle zone out there. The delicate, innocuous-looking tendril often has evil motives, using its tight curling abilities to choke the life out of the competition, or even to invade and parasitize other plants.

Tendril perversion

No, this is not what you think. Tendril perversion is a geometric phenomenon that occurs when a tendril switches the direction of the curl (chirality) halfway to its destination. It ends up being very common, but no one is really sure why it happens.

Unless you’re using a syringe filled with syrup, you’ve never really fed or watered your plants.

When you irrigate or fertilize your plants, what you are really doing is watering and feeding the soil. It is the soil that feeds and waters your garden and landscape plants. Creating healthy soil is the best way to grow healthy plants that need less protection from pests and diseases, produce more flowers and food, and require less work. So why is improving soil health one of the last things on our garden To-Do lists? Let’s learn more about growing great soil.

What is great soil?
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Soil is a highly complex natural body that scientists call the pedosphere. Some call it the Earth’s living skin. Soil stores water and nutrients, filters our drinking water, helps break down toxic wastes, and is a critical player in carbon cycling, nitrogen cycling, and, let’s face it, life on Earth. Soil is made up of minerals, dead things, living things, gases, and liquids. Great soil has spaces between its bits. These spaces, called macropores and micropores, hold and allow water and gases to flow, carrying nutrients to your plants. Great soil is rich in organic matter. Organic matter is made up of living things, and things that used to be alive. Great soil also contains the 17 primary nutrients required for plant development. But before you can grow great soil, you need to know what you already have.

What is in your soil?

The 17 primary plant nutrients are called macronutrients. Plants use the inorganic form of these mineral elements (read molecule-sized rocks). The only way to really know what is in your soil is with a soil test from a reputable local lab. By local, I mean on whichever side of the Rocky Mountains you reside ~ the tests used are different for each region. The Olson test is better for the West Coast, while the Brays test is better on East Coast.

Now, when your results arrive, you may be little confused by the information. That’s to be expected. Most of us do not read lab results on a regular basis. When I lived in San Jose, California, we tended to have clay soil highly prone to compaction. Aeration was frequently needed. Clay soil tends to contain plenty of most of the necessary minerals, and too much salt and phosphorus. Iron and nitrogen deficiencies are common around here. Other areas and soil types have other strengths and weaknesses. Your soil test results should include percentage ratings for each of the major plant nutrients. It may also tell you how much organic matter is in your soil.

Organic matter in soil

Organic matter is critical to soil health, and it can range from 1 - 8%.  As living things die and begin to breakdown, they add nutrients and improve soil structure. They also alter the electrical charge of soil. Quick chemistry review: molecules can be stable, with no charge, positively charged cations (cat-ions), or negatively charged anions (an-ions). Calcium, potassium, and many other plant nutrients are cations, while organic matter tends to be anions. Plants need both. Ensuring that there is enough organic matter in the soil also improves porosity, aeration, and biological activity.

Soil structure

Soil is usually described as being sand, silt, or clay. Sand is big. You can see individual particles. And water and nutrients can quickly leach away. Silt is made up of medium-sized particles that hold a good balance of gases, liquids, minerals and organic matter. Clay is made up of extremely tiny particles that can hold a lot of water and minerals. [It can also turn into concrete, especially if you add sand.] Organic particles surrounded by clay are protected from the microorganisms that break them down into nutrients that can be used by plants, creating an unattainable banquet. Identify your soil structure with the test found here. Each type of soil benefits from the following:

• Sand - add organic matter to help it retain water and nutrients
• Silt - add organic matter to help maintain the inorganic mineral and organic matter balance
• Clay - add organic matter to improve soil structure and porosity, and to speed the breakdown of organic matter

Do you see a theme here?

Adding organic matter to soil is critical to plant health. A 1% increase in organic matter can make a profound difference in soil structure (aggregation) and chemistry. This helps plant roots get to and absorb nutrients. You can add organic matter to your soil by:

• mulching with untreated chipped wood
• amending with composted kitchen and yard scraps
• incorporating aged manure from local horse and cattle farms
• raising chickens and composting their soiled bedding
• protecting bare soil with ground cover crops
• applying organic top dressings

Nitrogen

Once you’ve increased the amount of organic matter in your soil, you will want to add nitrogen. Nitrogen levels are the single most limiting factor in most gardens, and organic matter can help your plants access the nitrogen that is already present. Nitrogen is a highly mobile nutrient and it is easily lost. Most soils contain less than 1% nitrogen, while 2-5% is ideal. But it is not simply a matter of adding more nitrogen. Which form will you use? Inorganic nitrogen can be found as nitrites or ammonium. When roots take up nitrates, they increase the pH of the immediate area, making it more alkaline. The opposite is true when plants take up ammonium, making the soil more acidic. Organic sources of nitrogen include blood meal and cottonseed meal, both of which will acidify soil.

Soil pH

You can’t know which form of nitrogen is right for your soil until you know its pH. Soil with a low pH makes it harder for plants to access some macronutrients. Soil with a high pH does the same thing. Most plants prefer a pH of 6.0 to 6.5 to thrive. Growing great soil means identifying and managing your soil’s pH. 

Creating healthy soil

Soil creation is called pedogenesis. You can create great soil in your garden and landscape when you:

1. Learn what you already have, with a reliable soil test.
2. Regularly incorporate organic matter with compost, mulch, and even coffee grounds.
3. Analyze your soil structure and aerate, as needed.
4. Only add needed amendments, and in the proper form for your soil.
5. Determine your soil’s pH.

Other ways you can improve your soil’s health is by growing cover crops, using crop rotation, installing foot paths to reduce compaction, and avoiding irrigation run-off and urban drool.

What will you do for your soil today?

Organic pesticides and fertilizers

Many organic farmers still spray crops with chemical pesticides and fertilizers, it’s just that the chemicals they use must be from natural sources, and they must be dispensed using equipment that was not used with synthetic chemicals. That being said, some of the ‘natural chemicals’ used in organic farming are pretty awful. Just because something occurs naturally doesn’t mean it’s safe to eat. Death cap mushrooms are a perfect example. Also, good intentions are not always enough. Horse and cow manure are excellent for composting, but are you certain about which medications, diseases, or other ingredients might come along with that manure? Good cultural practices, garden sanitation, biodiversity, and composting can all help reduce the need for any type of chemicals in your garden or landscape.

Organic mulch

Mulch is an excellent way to protect unplanted areas, but where did it come from and what is in it? Mulch from tree trimmers is usually a good bet (and free!), but there is still no guarantee that the trees weren’t diseased or sprayed with chemicals. Even worse, mulch made from discarded lumber may contain arsenic. Yikes! You can use your own yard waste to create a relatively organic mulch and reduce landfills as the same time.

Organic potting and planting soil

Deciding to grow your own food isn’t as simple as it sounds, either. Does your bag of potting soil contain ground up car tires? What about styrofoam? Just because a bag of soil says ‘natural’ or ‘organic’ does not mean it is healthy for you or your plants. If you want truly organic, you must look for the certified OMRI (Organic Materials Review Institute) label.

Other organics

Sometimes we think we’re doing the right thing and it ends up being the wrong thing. For example, if you bought birdseed from 2005 to 2008, you may have been party to poisoning the very birds you were trying to help! Scotts Miracle-Gro knowingly sold birdseed tainted with chemicals toxic to birds, fish, and other wildlife. Would using organic birdseed have been better? Probably. [Personally, I won’t be buying ANYTHING* from Scotts Miracle-Gro. EVER.]

Before despair sets in, let’s turn around and look at the positive side of things. As I said at the beginning, organic farming and organic agriculture are on the rise. Sales of organic foods and textiles are also increasing. As more certified organic farms become established, the prices of organic foods drops, making them affordable for more people. That’s all really good news. Also, for every food item that you grow for yourself, you will have a far better idea what went into that plant before you eat it.

In the world of organic gardening and farming, the bottom line is: who do you trust with your family’s health?

​* Scotts Miracle-Gro sells the following product lines: Scotts, Miracle-Gro, Ortho, RoundUp, Tomcat, nature’s care. Osmocote, Substral, Evergreen, Nexa, Celaflor, KB, Fertiligene, Naturen, Weedol, Earthgro, and Hyponex, just so you know what I won’t be buying. What you do is up to you.

Cousin to bees, ants, and sawflies, wasps come in an astounding variety of good, bad, and indifferent garden insects. There are over 100,000 different types of wasps (Vespidae) around the world and only some of them will hurt you. But, ass anyone who has ever been stung knows, once is more than enough!

Wasp description

Wasps tend to have relatively long, slender bodies with the telltale wasp-waist, between the thorax and abdomen. Most wasps have two pairs of wings, though some are wingless. The variety is really pretty amazing. It’s a shame they are so painful. Did you know that wasps dangle their legs as they fly?

Why the sting?

Male wasps do not sting. Much like carpenter bees, it is the job of the female to protect and defend. As she hunts down food for herself and her colony, she will protect herself, her family, and her food sources with extreme prejudice. The stinger is actually a modified egg-laying organ. A wasp can sting multiple times and it really hurts. As a child, I would get them caught in my long hair. It was terrifying at the time! Swarms can be deadly.

Wasp lifecycle

There are social wasps and there are solitary wasps. Social wasps live in colonies, led by a queen. Some wasps burrow in the ground, some use mud to create apartment complexes, while others build paper nests. In these nests, the queen begins laying eggs. These eggs hatch into female workers. In late summer, some eggs hatch into male drones, whose sole purpose (in their very short lives) is to mate with the queen, after which, they die. Most social wasps are predators, killing many garden pests each year. As resources become scarce and colony size grows, these wasps become scavengers. Those are the ones that cause the most problems for us.

Yarrow is a trouble-free plant that offers many benefits in your garden or landscape.

Chickens, jays, and mockingbirds can wreak havoc on your fruit and nut tree crops unless you provide protection. 

Floating eye balloons, hanging old CDs, motion-sensing sprinklers, and noise cannons are just a few of the countless methods ‘guaranteed’ to protect your fruit and nut crop from marauding birds, but most of them do not work; not for long, anyway. Caging your tree is the only way to be sure that you get the lion’s share of your fruit or nut crop.

The netting used over your tree cage will still allow pollinators easy access. Unfortunately, it also allows codling moths and other flying insect pests to reach your fruit and nut trees. Even so, birds and squirrels can take a big bite out of apple, apricot, almond, nectarine, fig, and other crops. Tree cages can stop that damage before it even starts. Plus, these cages stay up, year round, so there's no wrestling with netting every spring and fall.

Store bought vs. DIY tree cages

Store bought tree cages can be astronomically expensive and most of the really nice ones are in the UK. The added shipping costs make it impossible or unrealistic for most of us. Luckily, it is surprisingly easy to make a tree cage yourself for less than $50. If you can scrounge old tree supports, it’s even cheaper.

Make your own tree cage
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This tree cage design is intended for dwarf variety trees that will be pruned to 6 to 8 feet tall and 8 feet wide. You can adjust the measurements for bigger trees, but longer lodge poles can be harder to find and more expensive.