Pea plants

Peas (Pisum sativum) are legumes, which means they have a tidy little business arrangement with certain soil bacteria, called rhizobia, which allow them to use atmospheric nitrogen. Pea seeds develop in pods, making them a pod fruit. Peas are either green or yellow and pods can be green, brown, or purple.

Peas are very easy to grow. They prefer cooler weather, making them excellent winter crops. While peas grow best in full sun, they can also work well for shade gardening and container gardening. Many birds love pea seeds, so you may have to protect your crop with netting until the seeds germinate.

Seeds should be planted 5” apart and 1" deep in rich, loose, moist soil. As they grow, vining pea plants will use tendrils to grasp and climb, so you will want to provide stock panels, tuteurs, or trellising for them to climb. As tempting as it may be to let your peas climb up netting, don’t do it. You’ll have a mess on your hands at the end of the growing season. Take my word for it. If peas are being grown in a container, a tomato cage works well.

Water regularly, allowing the soil to dry out between waterings, and be sure to harvest pods as soon as they are ready. This will keep the plant producing. Peas left of the vine will become too tough and starchy to eat, but they can be saved for planting or cooking. Succession planting can provide many months of harvestable peas.

Pests and diseases of peas

Fungal diseases, such as Ascochyta blight, basal stem rots, damping off, downy mildews, Fusarium wilt, powdery mildew, and root rot cause lesions and blackened areas on stems, roots, and leaves. Viral diseases include pea enation mosaic and pea streak, both transmitted by aphids. These diseases cause distorted pods and leaves. Pests include aphids, armyworms, cucumber beetles, leaf miners, nematodes, pea leaf weevils, pea moths, spider mites and thrips.

Forget the mushy peas of your childhood. Grow your own peas for a delicious treat!

Squash plants can have huge, healthy leaves and ripening fruit when suddenly everything wilts.

Slow wilting is usually the result of too little or too much water or a symptom of vascular diseases, such as Verticillium wilt and Fusarium wilt. When the leaves of cucurbits droop suddenly and the entire plant collapses, it may be due to a fungal disease called sudden wilt. Or it may be squash vine borers.

If you live east of the Rockies, squash vine borers can kill a plant within a few days unless the borers are found and removed. If you live west of the Rockies, and see a squash vine borer, contact your local County Extension Office immediately.

Squash vine borers frequently attack Hubbard squash, pumpkins, gourds, and zucchini. Butternut, cucumber, and melon plants are usually safe from squash vine borers. So far, anyway. 

Squash vine borer identification

Squash vine borers go through complete metamorphosis from caterpillar to moth. The adult moths look like black and red wasps. They are approximately 1/2” long with transparent hindwings and metallic green front wings. Borer larvae look like fat, wrinkled, white caterpillars with dark heads. Squash vine borer eggs are tiny, flat, brown, and oval.

Squash vine borer lifecycle

Adult borers overwinter underground in pupal cocoons. Adult clearwing moths emerge early to midsummer to lay eggs near the stems of favorite foods. These eggs hatch one or two weeks later, and the larvae burrow into plant crowns, stems, and occasionally fruit to feed for 2 - 4 weeks. One sign of squash vine borers is the appearance of piles of frass that look like wet sawdust.

Squash vine borer control

If you see a borer in a stem, you can cut it out with a sharp knife using a vertical cut or insert a sturdy wire into the burrow to kill the larva.

According to companion planting research, planting radishes near your squash plants mat repel squash vine borers. Interplanting squash and corn may disorient squash vine borers because of the different leaf shapes and stalk heights.

These tips can also help reduce the chances of squash vine borer infestations:

• Plant squash in a different location each year.
• While vines are small, sprinkle the area with diatomaceous earth (reapply after rain).
• Dispose of vines as soon as plants have finished producing fruit.
• Use row covers.
• Place a yellow bowl filled with water where borers are suspected. (Adults are attracted to the color and drown.) Yellow sticky sheets can also be used to trap squash vine borer moths.

I hope you never see squash vine borers in your garden.

Squirrels can inspire peanut generosity or thoughts of genocide.

These frisky little rodents can devastate a fruit tree crop, devour bulbs before they ever see daylight, and spread dangerous diseases. They are thieving, lying pests. And they are too cute for words.

Squirrel diet

Everyone knows that squirrels commonly eat nuts and acorns, but these pests have a far more extensive diet. A normal squirrel diet includes many garden favorites, such as citrus, pears, apples, avocados, and other tree fruit, mushrooms, crocus and other flower bulbs, and green vegetation. They also eat small birds, young snakes, insects, eggs, and smaller rodents.

Squirrel damage

In addition to damaging crops, squirrels also chew irrigation lines, electrical lines, PVC pipes, window frames, door frames, decks, and attic insulation. As squirrels move through an area, they mark their territory by urinating. (That’s the twitchy tail maneuver often seen on fences, trees, power poles and your roof.) Rodent urine can carry Leptospirosis and Tularemia, which can, in turn, lead to encephalitis, meningitis, kidney failure, or liver damage. The fleas and ticks that live on squirrels can also carry diseases, such as Bubonic plague and Lyme disease. Squirrels can carry leprosy and rabies.

Squirrel control

Unless you live in an area where shooting squirrels is legal, you are going to have a difficult time controlling these pests. If poison baits are used, June is the most effective month to use them, but poisoning is cruel and it runs the risk of poisoning non-target wildlife and pets. Personally, I encourage my dogs to chase the squirrels away and I built tree cages around my fruit and nut trees. I also use a liquid squirrel repellant that seems relatively effective. Mostly, I resign myself to some crop loss. Some people use live traps and then relocate trapped squirrels. The problem with this method is that, as long as there is a food supply, squirrels will continue to find your garden.

Some gardeners have resigned themselves to providing the local squirrel population with a steady supply of peanuts to protect their crops. To me, this simply increases the squirrel population even more, 

How do you protect your home and garden against squirrels?

Wilting is a common symptom of too much heat or insufficient water, but other factors can result in wilting.

​In healthy plants, water is used to hold them upright. Plants conserve water by closing their water stress. Plants fall over if they do not contain enough water. Surprisingly, too much water can cause the same symptoms.

Understanding the root cause of wilting can help you correct the situation and provide the proper treatment. Here are some other common causes of wilting:

• Bacterial wilt diseases—Wilting from bacterial infection is caused by Clavibacter, Erwinia, and Xanthomonas in tomatoes, cucumbers, corn, and cruciferous vegetables, respectively.
• Boring insects—Some boring insects, such as squash bugs, may damage vascular tissue, indirectly causing wilt.
• Fungal girdling—The Sclerontina and Botrytis fungi attack and girdle stems, which can cause wilting.
• Fungal wilt diseases--Fusarium wilt, onion white rot, and Verticillium wilt are just a few fungal diseases that block vascular tissues. These blockages prevent water from reaching stems and leaves, causing plants to wilt and, ultimately, die.
• Natural toxins—Some plants, such as walnut trees, produce toxins that cause other plants to wilt. Tomatoes are particularly susceptible to this form of territorial chemical warfare.
• Nematodes—Nematodes feed on root tissues, causing wilt.
• Transplant shock—Seedlings transplanted too early in their development into an unforgiving environment will often exhibit wilting. Underdeveloped root systems cannot absorb water and nutrients as readily as mature plant structures.
• Unnatural toxins—Many chemicals, especially herbicides, can cause wilting.

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Once the cause of wilting has been identified, treatments or solutions can be found.

Parts of the vascular bundle

Vascular bundles are made up of the xylem and the phloem. The xylem carries water and dissolved minerals up from the soil, through the roots, to stems and leaves. The phloem carries dissolved food, especially sugars, down, from the leaves, to storage tissues in the stems and roots.

There are various arrangements of vascular bundles, depending upon the type of plant. ​

Diseases of the vascular system

The flow of water and nutrients is critical to a plant’s health. Many pests and diseases take advantage of this fact. Damage to the vascular bundle can cause wilting, chlorosis, or even death. Common pests and diseases of vascular bundles include:

• Fusarium wilt (Fusarium oxysporum f. sp. chrysanthemi and f. sp. tracheiphilum)
• Verticillium wilt (Verticillium dahliae)
• Hollow stem (Erwinia carotovora)

Fun with the vascular system

You're never too old to enjoy this one and your kids are sure to enjoy it - put some celery stalks in a cup of water with food coloring and watch the dye move through the stalk's vascular system. Try it with other plants and show us pictures!  ​

Tomato spotted wilt is a viral disease spread by thrips.

Besides tomatoes, this virus can infect chili peppers, eggplant, lettuces, radicchio, peanuts, and fava beans.

Sunny days and cool nights make the best strawberries.

Like many other edible plants, strawberries grown and harvested at home tend to have much better flavor than store-bought varieties. While strawberries are grown commercially as annuals, they are actually a perennial plant.

Technically, they are not berries at all! Strawberries are actually aggregate fruits, along with raspberries and blackberries. And those tiny seeds are a special variety of seed known as an achene, which is actually a dried fruit!

How to grow strawberries

Strawberries make excellent container plants. They grow very well in towers, raised beds, narrow planter boxes, and even rain gutters can be used. Ideally, containers should be 6 - 8” deep and at least 18” long. Potting soil mixed with aged compost or organic fertilizer should be used to provide plenty of nutrients. Use these steps to successfully grow strawberries in the ground:

• Select a sunny location where members of the nightshade family (tomatoes, peppers, eggplants) have not been planted in the past 3 years.
• Clear the planting area of all weeds.
• Amend the soil with aged compost or manure and fertilize with alfalfa meal.
• Build rows that are 6” tall and 10” wide, with each row being 28” apart.
• Cover the planting area with straw.
• Plants should be placed 10 - 14” apart. 
• Crowns should be at or just above the soil line after watering.
• Drip irrigation is ideal because it keeps the soil moist.
• Prune any runners the first year to encourage fruit and root development.

Strawberry varieties

Strawberries are classified as either “day-neutral” or “short-day” varieties. Day-neutral strawberries, also known as “everbearing", flower and produce fruit year round, peaking April through October. Aptos and Fern are popular everbearing strawberry plants. Short-day varieties, such as Pajaro, Seascape, Tioga and Chandler, produce more as days become shorter, in fall, through early spring. 

Strawberry pests & diseases
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Slugs and snails, earwigs and sowbugs will eat fruit that is lying on the ground, which is why a barrier of straw is used to cover strawberry beds. Keeping fruit off of the ground will also reduce berry rot. Powdery mildew, Botrytis fruit rot (gray mold), Verticillium wilt, and leaf spot diseases are common on strawberries.

Strawberries occasionally undergo a process called vivipary, in which each tiny seed sprouts a leaf.

Stolons are one way a plant can regenerate. Stolons send new roots down at the nodes and new stems up at the buds. Strawberries and potatoes grow from stolons.

New plants produced by stolons are clones of the parent plant, or genet. Some turf grasses, such as St. Augustine grass and various bent grass species, grow from stolons. Other grasses, such as Kentucky bluegrass and red fescue, grow from rhizomes. In either case, this growth habit makes it possible to grow new plants from plugs. It is also why some weeds are so difficult to eliminate.

Every year, around July and August, gardeners begin seeing the effects of aphids, leafhoppers, spider mites, thrips, and other pests. In most cases, these insects have piercing mouthparts with a built-in straw. Pretty convenient, if you’re an insect. Sucks if you’re a leaf.

Leaf stippling won’t seriously harm an otherwise healthy plant, but it can interfere with photosynthesis and may compound water-stress.

If leaf stippling is visible, be sure to inspect plants for the cause. By knowing what you and your plants are up against, you can select the most effective treatment.

Hint: many sap-sucking bugs can be dislodged with a powerful stream of water from the hose.

Sap is carried up the trunk or stem of a plant in the xylem and down through the phloem. Sap has different components, depending upon where it is found. Xylem sap carries water, hormones, and minerals from the roots to the leaves. Phloem sap conducts sugars, hormones, and minerals from leaves, where carbohydrates are produced through photosynthesis, to where they will be used or stored. Within the tiny cavities (vacuoles) of each plant cell, cell sap can be found. Cell sap contains sugars, waste, and minerals.

Who and what eats sap?

Well, we do, for one. Sap from sugar maple trees is boiled down to make maple syrup for our pancakes. Most living things, however, have a hard time eating sap. This is because they lack certain gut microorganisms that aid digestion. That being said, members of the Hemiptera order, or true bugs, have no such problem.

Aphids, leafhoppers, sap beetles, spider mites, scale, and mealybugs all enjoy feeding on the sweet, sugary sap of your garden plants. In addition to these pests, there are many living things that feed on sap indirectly, by eating the honeydew excreted by the sap eaters, including ants and whiteflies. [You may be surprised to learn that honeybees also collect honeydew and use it to make a unique, darker honey that is prized in Europe.] Sap from the aloe vera plant is widely used to help heal burns and other skin conditions.
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What sap is not

Plants produce other liquids besides sap. These include latex, resin, and gums. When you pluck a ripe fig from your tree, or tug a dandelion from the lawn, the white milky ooze you see is not sap. It is latex and many people have skin sensitivities to it. Ten percent of all flowering plants (angiosperms) produce latex in response to injury or invasion. Latex is made up of sugars, oils, starches, alkaloids, resins, proteins, and gums. Gums are made from decomposed cellulose, while resins are made from essential oils. Fossilized resin is the gemstone amber. [Our word for electricity comes from the Greek word for amber because the stones create static electricity when rubbed.]

Redhumped caterpillars are pests of ornamental and fruit trees.

Redhumped caterpillars (Schizura concinna) most often attack sweet gum (liquid amber), plum, and walnut trees, but they can also be found on pear, apricot, cherry, almond, apple, birch, prune, and willow.

Redhumped caterpillar lifecycle & identification

Redhumped caterpillars are 1" to 1-1/2" long and yellowish, with an orange or brick red head. The fourth segment is also red, with a distinct hump and two black spines (tubercles). Other segments have their own tubercles, but they are less visible. You may be able to see longitudinal stripes of white, brown, brick, or black along the body. In autumn, these caterpillars fall to the ground and spin themselves into a cocoon. The pupa is often found when working the soil. It is 1/2 inch long and reddish brown. In April and May, the moths emerge. Adult moths have a wingspan of 1 to 1-3/8 inches. The forewings are gray to reddish brown and the hind wings are pale white, gray or brown. A dark line may be visible along the back of the forewings. After mating, female moths lay clusters of 25 to 100 spherical, white eggs on the underside of young leaves. There can be 4 or 5 generations each year.

Rutabagas look funny, their name sounds funny, and, let’s face it, they have a rather odd family history.
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Imagine deciding to cross a cabbage with a turnip. What would you get? A rutabaga! The name comes from the Swedish words for stumpy root and it was first noted as growing wild in the early 1600s. Rutabagas are also known as swedes, yellow turnips, and Russian, Canadian, and Swedish turnips. The scientific name, Brassica napobrassica, tells us that it is a member of the cabbage family, which includes broccoli. 

Rutabaga description

Rutabagas are biennial plants, which means they take two years to go through their complete lifecycle. The first year is dedicated to vegetative growth and the second year is used for seed production. The root we eat is actually made up of the base of the leafy stem (think cabbage) and the hypocotyls, which is part that grows between the true root and the first seedling leaves (cotyledons). You can tell the difference between a turnip and a rutabaga by the ribbed neck seen on rutabagas. Rutabaga flowers are small and pale yellow.

How to grow rutabagas

Rutabagas grow and ripen best in cool weather, making August and September the best time to start seeds. Rutabaga seeds should be planted 1/2” deep in rich soil. They transplant well, so starting them in small containers is a good way to give them a head start. Seedlings should be placed 12-18” apart. Rutabagas grow a little larger than turnips and need a few extra weeks to reach maturity. They are normally ready to harvest within 80-100 days. Rutabagas can grow pretty much anywhere, but their flavor and texture improve significantly when they are grown in soil treated with compost and watered regularly. Insufficient watering can cause a woody texture and splitting can occur with irregular watering. Soaker hoses are an excellent idea for rutabagas. Rutabagas prefer a pH of 5.5 to 7.0 and a rock-free environment. Like other brassicas, rutabagas should not be grown in the same spot for more than 2 years at a time.

Rutabaga pests and diseases

Rutabagas actually provide good weed suppression with their thick, broad, blue-ish colored leaves. Rutabaga leaves are frequently eaten by cutworms, caterpillars, root maggots, wireworms, flea beetles, aphids, and slugs, but I've never noticed any damage to the roots themselves. Using row covers while the plants are small can protect them from many of these pests as long as the covers are in place before the pests arrive. Planting mint, garlic, nasturtium, fennel, or marigold nearby can either repel or act as a trap crop. Clubroot is a fungal disease found in poorly drained, acidic soils. This fungus can remain viable in the soil for up to 20 years, so keep your rutabagas away from any areas that have ever been infected.

How to harvest and store rutabagas

One of the reasons rutabagas are an important fallback food in times of starvation is that they store well. Rutabagas should be harvested when they are about the size of a grapefruit. When rutabagas are small, they are more tender. As they mature, they become sweeter. To harvest rutabagas, simply pull or dig them from the ground. You can leave them in the ground for longer periods of time by trimming the leaves and heavily mulching the area with straw. Harvested rutabagas can be stored for months by trimming all but the top inch or two of greenery and storing in a cool, moist location, as close to 32-degrees F as possible, without freezing. Commercially, rutabagas are dipped in paraffin wax to prolong storage.

Rutabagas as food

Rutabagas are grown for the their roots and leaves. The roots are a starchy equivalent to potatoes in soups, stews, and casseroles. In Scotland, potatoes and rutabagas are boiled and mashed separately to create ‘tatties and neeps’ - now’s there’s a fun menu item! An interesting note, thanks to genetic research: some people find rutabagas, as well as watercress, horseradish, and broccoli, extremely bitter-tasting, compared to the rest of us. This is due to a specific gene that affects the bitter taste receptor. So, if someone says they really can’t eat members of this group, they may be telling you the truth! In our family, we have discovered that roasted rutabagas are surprisingly delicious!

A serving of rutabaga roots contain 42% of the RDA for vitamin C. The tender new greens can also be eaten, just be sure to only remove a few leaves per plant. They can add a zesty bite to salads.

Their tiny leaf-shaped feet may looking charming, but these cousins to stinkbugs can cause almonds, tomatoes, pistachios and pomegranate fruit to be aborted.

Leaf-footed bug description

Leaf-footed (or leaffooted) bugs are medium-sized insects with long, sucking mouthparts. Adults are normally 3/4” to 1” long, with a narrow brown body. Leaf-footed bugs (Leptoglossus) are easy to identify because of the leaf-shaped bits sticking out of their hind legs. There are three species of leaf-footed bugs native to the western United States:

• L. zonatus 
• L. clypealis
• L. occidentalis (western conifer seed bug)

The three species look very similar, except that zonatus has two yellow spots behind the head and clypealis has a thorn-shaped plate on the front of its head called a clypeus. All species of leaf-footed bugs have white zig-zags on their wings.

Leaf-footed bug lifecycle

Leaf-footed bugs overwinter in wood piles, citrus or juniper trees, or buildings. They can also be found under tree bark. In spring, adults fly in search of winter weed seeds, young fruit, and a place to lay eggs. Leaf-footed bugs that have survived the winter can carry 200 eggs. These brown, cylindrical eggs are laid in a line, end-to-end, usually on a stem or leaf midrib. Nymphs emerge from the eggs and can be identified by the dark head and legs, and orange to reddish-brown body color. Leaf-footed bug nymphs are often confused with nymphs of the beneficial assassin bug (Zelus renardii), which have lighter colored legs and antenna. Also, assassin bug eggs are barrel-shaped and laid together in groups that are protected with a white cone covering.  

Leaf-footed bug damage

Leaf-footed bugs generally do not do a lot of damage. This changes when populations are especially high, due to mild winters. Adult L. zonatus feed on tomatoes, pomegranates, almonds, pistachios, and watermelon. L. clypealis prefers palm trees and yucca, while L. occidentalis feeds primarily on conifer trees. All three species feed on many ornamental trees and shrubs. Leaf-footed bugs have mouthparts that pierce fruit, shoots, and leaves, to suck out plant juices. Leaf-footed adults are able to probe deeply enough to reach fruit seeds. When a seed is found, digestive enzymes that liquify the seed are excreted. Damage to the seed often causes the parent plant to abort that particular nut or piece of fruit. Leaf-footed bug mouthparts are also known to carry a fungal yeast (Eremothecium coryli). As the bugs feed, this yeast is introduced into the fruit or nut, causing depressions or discoloration, but no other damage. Of course, like most bugs, they do poop on your fruit.

Generally, control measures are not needed. If leaf-footed bugs have become a problem, these sanitation measures will help:

• Keep wood piles away from buildings and eucalyptus and conifer trees.
• Dispose of culled fruit.
• Eliminate seed-bearing weeds.
• Use row covers.
• Inspect plants daily and handpick. Bugs can be crushed (they stink!) or dropped in a can of soapy water.
• Encourage predators, such as birds, spiders, tachinid wasps, and assassin bugs by providing water and natural habitat.
• Avoid using broad-spectrum pesticides that can kill predator insects.

When it comes to perennial herbs, rosemary, oregano and thyme are the stuff of Italy’s finest. Rosemary is a fragrant woody herb that takes little to no care to provide decades of lovely color, fragrance and landscape structure.

Rosemary was thought to be a member of the mint family. This fragrant evergreen can produce purple, pink, blue or white flowers that are favorites of honey bees.

​Rosemary as companion plant

According to companion planting research, the astringent characteristics of rosemary have been found to repel cabbageworms, carrot flies, Mexican bean beetles, slugs and snails.

How to grow rosemary

Rosemary thrives in hot, dry weather, providing pollen and nectar for honeybees and other pollinators, without consuming a lot of water. This drought-tolerant perennial can be sheared into decorative shapes, used as a fragrant hedge, or allowed to fill an area naturally. It can also grow well in cooler, cloudy places. Rosemary is easily grown in containers, indoors or out. Rosemary prefers a slightly alkaline pH (7.0 - 7.8) and well-drained soil. Rosemary can be propagated by taking 6" of new growth and planting it.

Rosemary pests

Very few pests or diseases bother rosemary. Spittlebugs may be found on rosemary but they are easily displaced with a spray of water from the hose.

The most obvious perennial plants are trees, some of which live for hundreds, or even thousands, of years. You won’t get that kind of longevity from shrubs, bulbs, or other perennial plants, but you will get the other benefits of growing perennial plants.

Advantages of perennial plants

The single biggest benefit of perennial plants is that they do not have to be planted each year. Perennials are able to develop more extensive root systems, making them less susceptible to drought and able to reach more nutrient resources. This makes them more resilient to water stress and more resistant to pests and disease than more tender annuals.

Perennial flowers

Flowers add more than color to a landscape. Nectar and pollen attract beneficial insects that attack pests and increase yields through improved pollination. Perennial flowers, such as lavender, hydrangea, daisies, echinacea, hollyhocks, phlox, crocus, and tulip can either add year round structure or seasonal splashes of color to the garden.

Perennial herbs

Most herbs are tenacious perennials. Planting rosemary, thyme, bay laurel, chives, fennel, lemon balm, oregano, lemongrass, marjoram, mint, ginger, parsley, sage, and tarragon can provide many years of culinary delight with very little effort on your part. The only exception is parsley, which is technically a biennial. Biennials take two years to complete their lifecycle, although I have had parsley plants last 3 - 4 years.

Perennial shrubs & trees

By definition, all shrubs and trees are perennial, but a few varieties provide the added benefit of being edible. Edible shrubs include blueberries, currants, gooseberry, hazelnut, pineapple guava, and dwarf pomegranate. Trees can provide a wealth of fruits and nuts in practically any landscape.

Perennial vines & cane fruits

While grape vines are most productive during their first 20 years of life, they can continue for over 120 years, making them one of the longer-lived perennials. While they may not look neat and tidy in a landscape without a fair bit of effort on your part, blackberries, raspberries, dewberries, loganberries, and boysenberries also deserve consideration for the delicious fruit they provide year after year.

Other perennials

Aside from herbs, trees, and shrubs, there is another perennial that deserves mention: stonecrops. Stonecrops are a family of succulents that come in a wide range of amazing shapes and colors. Succulents can survive even the worst neglect and still plump right back up after a light rain or watering.

Perennial weeds

Of course, the same strengths that make perennial flowers, trees, and shrubs so durable also makes some weeds harder to get rid of in the garden. Annual dandelions may require some effort to dig out, but perennial bindweed roots can go 14 feet deep or more!

Adding perennials to a landscape creates a stronger sense of continuity between the seasons and the passing years. Unlike the fleeting acquaintances of annuals, perennials establish themselves as durable members of the landscape.

Common stonecrops

While all stonecrops have fleshy leaves with a thick, waxy cuticle, the variety of shapes and colors make these plants excellent low-maintenance additions to practically any landscape. Their geometric patterns can be quite lovely. While Jade plants are one of the most common stonecrops, many sedum plants are recognized for their beauty and ease of care. The shapes of these amazing plants is so striking that potted collections can often be sold for well over $100. As easy as these plants are to
propagate, however, there is no need to spend that kind of money. Find a friend who already has a few specimens, trade some of your own, and get creative with a container or garden location!

Scale insect identification 

There are dozens of scale insect species. They can be found in a variety of sizes, shapes and colors. Generally, however, females and nymphs live under a circular shell, or scale. They have no discernible head or appendages. Adult males are almost never seen, being tiny winged insects. Some scale species have only females that can reproduce without mating. Most armored scale insects (Diaspididae) feature a 1/8” flattened cover with concentric rings and a slight nipple-shaped center. If the cover is removed, the animal will remain on the plant. Euonymus, oystershell, cycad, and San Jose are common armored scale species. Soft scale (Coccidae) insects can grow to 1/4” and they have a humped, waxy surface that cannot be removed. Soft scales feed on phloem sap. Common species include Kuna, Lecanium, Tuliptree, black and brown soft scale.

Identifying scale damage

Scale insects often go unnoticed until the damage is extensive. In some cases, scale insects can practically cover a plant without causing ill effects. Normally, plants infested with scale appear water-stressed because the pests are draining the plants of their bodily fluids. Chlorosis (yellowing) may also occur. Some varieties of scale produce honeydew that attract ants and provide habitat for sooty mold. Armored scale species do not secrete honeydew. 

How to control scale infestations

Control measures depend on the type of scale insect, as well as environmental conditions and the overall health of the plant. In some cases, no treatment is needed. Sago palm and other cycads, however, can be infested with the cycad scale, which can kill mature plants. Applying fixed copper combined with horticultural oil when the plants are dormant or when these pests are in the crawler stage (late winter to early summer) can help control scale insects.

​There are many natural enemies that help control scale, as long as broad-spectrum pesticides are not used. Inspect infested areas to see if the scales are being parasitized. If a small hole can be seen in the shell of a dead scale, it has been killed by a parasitic wasp and treatment is probably not needed. Applying sticky barriers around the trunks of heavily infested trees and shrubs can stop ants from protecting soft scale insects from their predators.​

Sap beetle description

Sap beetles are tiny (0.1" to 0.2" long), flat, and usually brown or black. They are active and move quickly. There may be spots on short wings and the antenna are clubbed. Larvae are white with a tan head, 3 pairs of legs and 2 horn-shaped structures on their back end. There are several varieties of sap beetle, also known as dried fruit beetles. These most common varieties are:

• Dried fruit beetle (Carpophilus hemipterus)
• Freeman sap beetle (C. freemani)
• Confused sap beetle (C. mutilatus)

Less common varieties include:

• Carpophilus marginellus
• Haptoncus luteolus
• Urophorus humeralis

Sap beetle damage

Sap beetles damage fruit by feeding, transmitting disease, and making fruit more appealing to other pests. Sap beetles create a hole near the stem of ripening fruit, where they enter and begin feeding. They begin by attacking fruit that has fallen on the ground, but ripe and overripe fruit left on trees can draw these pests upward. Sap beetles can act as disease vectors, spreading brown rot, Fusarium wilt and other fungal diseases. As damaged fruit begins to rot, other pests, such as navel orangeworm and vinegar flies, are attracted to the tree.

How to control sap beetles

Sanitation offers the best control of sap beetles. This means removing all fruit as soon as possible, including fruit that has fallen or mummified on the tree. Before fruit starts ripening, containers of fruit, water and yeast may be used to attract and drown sap beetles. 

What is salt?

Most people think of salt as the ‘and pepper’ variety. Table salt (NaCl) is the crystalized form of equal parts sodium (Na) and chlorine (Cl). Salt is necessary for human life and we’ve been processing it for over 8,000 years. In fact, as Roman Legions were sometimes paid a salt stipend (salarium), the word evolved into “salary”. But in the garden, salt is more of a chemistry class than a history class. Chemically, a salt is any compound that is formed when an acid reacts with a base, bumping all or part of the acid’s hydrogen atoms off and replacing them with a metal or other cation. This neutralizes the acid. [Don’t panic - keep reading]

Chemistry 101: anions & cations

In case it’s been too long (or never) since you had a chemistry class, everything is made up of atoms. Atoms have a nucleus with neutral neutron(s) and positively charged proton(s) and negatively charged electrons flinging themselves in semi-orbit around the nucleus. If the number of protons and electrons are equal, the atom is stable. If an electron gets bumped out of orbit, the atom becomes positively charged and it is called a cation [KAT-i-on]. If an extra electron is lured into orbit, the atom becomes negatively charged and it is called an anion [AN-i-on]. The reason this is important to gardeners is because the electrical charge of the atoms and molecules that make up the soil determine how many nutrients are available to plants. This is called the Cation Exchange Capacity. 

Salts in the soil

There are many ways salt can make its way into garden soil. Ocean breezes, de-icing and over-fertilizing can all cause salinity levels to rise. Drought is another major factor in soil salinity. As ground water reserves are depleted, the mineral content increases and that means more salt. Ammonium and nitrate are excellent sources of nitrogen and they are commonly found in fertilizers in salt form. Gypsum and lime also contain salts. Normally, salts are leached out of the soil by rain and carried below the level of most plant roots, but not always.

Plant reactions to salt

Normal healthy soil contains many dissolved salts. These include:

• sodium (Na+) 
• calcium (Ca2+)
• magnesium (Mg2+)
• chloride (Cl-)
• sulfate (SO4 2-)
• bicarbonate (HCO3-)
• boron (B)

As plants absorb water and nutrients through their roots, the water extraction can increase salt levels in the soil. Salt in the soil can stress plants, reducing root growth. If too much salt is absorbed, the plant is unable to perform photosynthesis and it will die. This is because of osmosis.

​Osmosis is the process by which a liquid (water) flows through a semipermeable membrane. Minerals (solutes) held in that water, and their electrical charges, pull water across the membrane, from areas of low mineral concentration to areas of high concentration. When this happens in plants, the sugars and organic compounds normally found in plant cells attract water from the soil and pull it into the plant, along with important nutrients. When there is too much salt in the soil, this process is reversed and plants are deprived of important nutrients and water. Too much salt in soil can also lead to other elements, such as boron (B) reaching toxic levels. Symptoms of this toxicity include burnt-looking leaf edges, especially in older leaves, yellow streaking, and wilting. [I learned that the hard way when I watered my house plants with a batch of brine shrimp that died overnight. I lost over 180 of my 210 plants.]

To prevent excess salt in the garden, minimize the use of chemical fertilizers during drought and use rain barrels to collect low-salt rain water. Water from rain barrels can help offset the higher salt levels found in tap water.

The crisp, slender stalks of scallions are easy to grow and they take up very little space in a garden or on a windowsill.

Scallions, also known as green onions or spring onions, can either be immature onions before they set bulbs (spring onions), or a specific variety of Allium that never forms significant bulbs.

Scallions in the garden

Scallions can be grown in window boxes, indoor planting containers, hanging planters, or in the ground. They can be grown in full sun or used in shade gardening. The spiky forms of newly growing scallions add a pretty accent to many plantings.

​How to grow scallions

Seeds can be started at any time of year and seedlings can be grown indoors or out. Seeds should be heavily planted, 1/2" deep. Scallions can grown in clumps, so there is no need to thin transplants. Scallion seeds require moisture to germinate and they can take a month to get started. Keep the soil moist and be patient. Like other onions, scallions have a shallow root system, so proper irrigation and frequent, gentle weeding are important. Scallions are heavy nitrogen feeders, so feed regularly with fish emulsion, blood meal, or alfalfa meal. Planting a new batch of scallion seeds every three weeks will keep you supplied with scallions year round. Also, each time you snip the base off of a scallion, those roots can be replanted to grow a new scallion!

Scallion pests and diseases

Scallions may be attacked by thrips. Thrip damage gives the leaves a white streaked look. Thrips can be reduced by spraying plants with soapy water. If tunnels are found in the underground portion of the plant, it may be onion maggots. Most members of the onion family are susceptible to onion white rot and other fungal diseases, such as onion rust. If nematodes are feeding on the root system, plants will appear stunted or deformed.

Onion white rot lifecycle

Sclerotium cepivorum fungi strike onions, garlic, and other Alliums. Onion white rot can stay viable in the soil for over 20 years. Unlike other fungi, this one does not produce spores. Instead, it survives in the soil as sclerotia (dormant fungal structures with stored food). These sclerotia can travel by piggybacking on equipment, people, tools, plants, and wind. 

A single sclerotium in 20 pounds of soil will infect nearby plants. One or two sclerotia in one pound of planting soil will cause all plants to be infected. The sclerotia will stay dormant in the soil until Allium comes on the scene. As part of their growth, these plants discharge certain chemicals into the soil around their roots. These chemicals stimulate the fungi to germinate. Soil temperatures of 50° to 75°F allow the fungi to grow, peaking between 60° to 65°F.

Onion white rot symptoms

Onion white rot first appears as a cottony growth around the base and sides of onion or garlic. These fungal mycelia are vegetative growths that become compacted. These poppy seed-sized black spots are visible to the naked eye. Other signs of infection are yellowing lower leaves, wilting, and leaf dieback. Older leaves will begin to rot at the base, and roots will decay, making it easy to pull infected plants from the soil. Host plants die soon after infection. Onion white rot travels sideways, from plant to plant, using intertwined roots as a pathway. This problem thrives in cool, damp soil.

Onion white rot control

This disease is persistent in the soil. And there are no known chemical controls. Once an infection has occurred, sanitize all tools and equipment that may have come into contact with it and avoid planting Alliums in that location for at least 8 - 10 years. If that is not an option, starting onions from seeds rather than sets (transplants) may help. The seeds will have minimal root growth while the fungus is most active. Onions grown from seed take two seasons to mature, so the problem may not be avoided entirely. Also, spacing onions 12 or more inches apart may halt the spread of this fungus. You may be able to save some of your onions with deficit irrigation. Leeks are the least susceptible members of the Allium family.

Due to the direct link between onion and garlic chemical exudates and fungal germination, research is underway to see if applying Allium plant hormones to infected soil without a host crop might trick the sclerotia into germinating when there is no food for them. Since this is not an option for the home gardener, prevention is the best bet.

Plant only certified pathogen-free onion sets and garlic cloves to avoid infecting your soil with white onion rot. Since onions and garlic purchased from grocery stores are not guaranteed pathogen-free, keep them out of the garden and the compost pile.