Most other plants are referred to as passive selenium accumulators. These plants can absorb too much selenium and suffer toxicosis. This is especially true for grasses and cereals, such as barley.


Toxic soil can be corrected with something called phytoremediation. Phytoremediation takes advantage of the fact that some plants absorb toxins through their roots. Before plants can cough those toxins into the atmosphere through their stems and leaves (transpiration), the plants are harvested and disposed of safely.


Signs of selenium toxicity

Selenium toxicity appears as stunting, early leaf death, and chlorosis. Leaves of affected plants may wither and dry up. High selenium levels in the soil can also cause copper, iron, and zinc deficiencies. Of course, these symptoms can mean several other things, as well. You will have to consider symptoms, location, and the presence of the aforementioned plants in your analysis.


Too much selenium in the soil can make your edible plants toxic. This can be the result of native bedrock. It can also be caused by industrial runoff. If you suspect high selenium levels in your soil, contact your local County Extension Office or Department of Agriculture.

Predatory mite lifecycle

The life of a predatory mite is short. Once the eggs hatch, they quickly go through a 6-legged larval stage and two 8-legged nymph stages before reaching adulthood. In her 30-day life, an adult female predatory mite will lay up to 21 eggs on the underside of leaves, in flowers, and within the crevices of buds. Depending on the weather, those eggs will hatch in 1 to 4 days. There can be up to 10 generations each year.


It is difficult to know if predatory mites are present because of their size, but you can buy them. They will help protect your avocado, citrus, grape, plum, strawberry, and many other crops. Before you release your predatory mites, be sure to reduce dust in the area by giving everything a quick rinse with the hose. You’ll want to avoid broad-spectrum pesticides and miticides, as well.

Organic mite control

Diatomaceous earth (DE) can also be used against mites and spider mites.  It desiccates them and kills them without leaving any chemical residue. Other food-grade dusts that also kill these pests without chemicals. These other dusts have an advantage over DE in that they do not contain silica. Breathing in silica dust is bad for us, too.


There are also predatory mites that prey on mites and spider mites.

Whichever treatment you decide to use, don’t apply it on a windy day. It and your money will simply fly away on the breeze. To be effective, sprays and dusts must coat the underside of all the leaves affected by mites or spider mites.


Now, about those rhinos

​Rhino poaching is being deterred by drilling holes in the horns of sedated rhinos and packing those holes with miticides. It doesn’t hurt the rhinos, but it brings on nausea, diarrhea, and convulsions in anyone who eats the horn, thinking it will provide them with some magical powers. And it won’t kill them. I think it’s the least punishment they should have to suffer for needlessly killing an endangered animal, don’t you?

Pea leaf weevil identification

Pea leaf weevil adults are one-fifth of an inch long, grayish-brown, and rather slender in physique. If you look closely, you may be able to see three pale lengthwise stripes down the thorax. Larvae are milky white with a dark head. Like other grubs, they tend to hold themselves in a C-shape. These larvae have no legs and are about the same size as adults. Eggs are white at first but turn nearly black just before hatching.


Pea leaf weevil lifecycle

These pests tend to have one generation each year. After overwintering in protected feeding grounds, adults fly and walk to new territories where female pea leaf weevils will lay 1,000 to 1,500 eggs on or near young legume plants. When those eggs hatch, the larvae enter the soil where they go through five developmental stages or instars. They feed heavily on the nodules that allow legumes to convert atmospheric nitrogen into a form they and neighboring plants can use for food. While these pests feed on all legumes, they only reproduce on peas and fava beans.


Pea leaf weevil management

Commercial growers apply insecticidal seed treatments before planting, but that’s probably not an option for the home grower. The good news is that black clock beetles, ground beetles, and rain beetles all love to eat pea leaf weevils. By mulching and applying aged manure and compost around your legumes, you can encourage these beneficial insects. This will also provide your legumes with any nitrogen they may need.


As always, avoid using broad-spectrum pesticides. Those chemicals end up killing off all your helpers. Bacillus thuringiensis (Bt) can also be used against these pests, but it only works on the weevils it touches. Eggs and larvae will be unaffected. These other tips can help protect your peas and other legumes from pea leaf weevil damage:

• Buy certified pest- and disease-free seeds and seedlings.
• Employ crop rotation.
• Reduce soil compaction with aged compost and mulch.
• Plant early-maturing varieties suitable to your microclimate.
• Grow peas away from other legumes, including alfalfa and clover.
• Use row covers.
• Keep plants properly fed and irrigated to help them recover from any damage that may have occurred.
• Completely remove pea plant debris at the end of each growing season and compost it or trash it.
• Handpick pea leaf weevils and drop them into a container of soapy water or feed them to your chickens.

 
I hope that pea leaf weevils never find your garden.

I thought I saw a whitefly on my apartment windowsill, but I was wrong. It was a dustywing.

Unlike whiteflies, which can carry diseases and suck the sap from your garden plants, dustywings are beneficial predators. They prey on slow-moving invertebrates, such as aphids, mites, and scale insects. They also eat arthropod eggs, including corn earworms, mealybugs, and tomato hornworms.


Dustywing identification

These net-winged hunters are very tiny. Their wingspan can range from one-twentieth of an inch up to one-fifth of an inch wide. They are covered with a whitish or grayish powdery wax. They secrete that wax from glands on the abdomen, head, and thorax. [Imagine being able to create your wardrobe that way!] They have tan-colored translucent wings and short antennae. Eggs are oval, yellowish-pink to orangish, and somewhat flattened. Larvae are red and white.

Dustywing lifecycle

Dustywings are commonly found around woody plants. They are mostly active at dusk (crepuscular) and attracted to lights. Each female can lay up to 200 eggs. These eggs are laid singly on nearby leaves and on the bark. There are two generations each year. Each larva goes through four instars. And all that growing requires a lot of food. A single dustywing larva was recorded as eating 226 red mites. That’s what I call helpful!

​
You can encourage dustywings to stay in your landscape by providing woody shrubs for them to live in and avoid using broad-spectrum pesticides. Have you seen dustywings in your garden? I released mine into the Seattle wilderness.

The papaya ringspot virus (PRSV) mutated, traveled, and expanded its diet to include several common garden plants. These include members of the squash family, tree spinach (Chenopodium amaranticolor, aka C. giganteum), peas, castor beans, and quinoa (C. quinoa). Currently found in the U.S., Europe, India, the Middle East, and South America, it is safe to say that papaya ringspot falls under the plant pandemic category.

​
Papaya ringspot symptoms

Like many other viral plant diseases, papaya ringspot looks like infected cucumbers and melons have developed measles. A mosaic of scattered dark green or intense yellow spots appears all over the fruit surface. Blisters may also be seen. Leaves of infected plants are chlorotic and distorted and may develop shoestringing. Stems and petioles may have oily streaks. This disease looks a lot like watermelon mosaic. In both cases, infected plants should be removed and tossed in the trash.

Papaya ringspot lifecycle

This virus congregates around the mouths of aphids, never actually entering the pest. As the carrier aphid feeds on sap, the virus moves from the aphid’s face to the plant’s veins. Wouldn’t that make an interesting video?


The papaya ringspot virus can also travel on seeds and seedlings.


Papaya ringspot prevention

There is no cure for papaya ringspot, and it can spread to neighboring healthy plants. Quarantining new plants and investing in certified pest- and disease-free seeds and seedlings are the best ways to prevent the papaya ringspot virus from attacking your garden.

Barley yellow dwarf host plants

Barley, corn, and the ryegrass and fescue in your lawn are not the only plants that can become infected with this disease. All members of the grass family (Poaceae) are susceptible.This means that your millet, oats, rice, rye, ryegrass, sorghum, sugarcane, and wheat can also become infected with barley yellow dwarf.  It is the costliest disease worldwide of all cereal crops. ​

Barley yellow dwarf prevention

Fungicides are ineffective against barley yellow dwarf. Instead, good cultural practices are your best plan of attack. Since aphids are the vectors for barley yellow dwarf, planning your planting schedule around aphid migrations can help reduce the likelihood of disease occurring. I know that aphid migrations aren’t usually mentioned on the evening news. But regularly monitoring your plants for aphids will make it very clear when they arrive and start reproducing. Planting seeds at times when aphids and seedlings are less likely to occur at the same time will help reduce disease. These other tips will also help keep your garden plants healthy:

• Plant resistant cultivars.
• Eliminate grassy weeds and volunteer cereals.
• Spray heavy aphid infestations with insecticidal soap.
• Encourage beneficial predators and parasitic wasps with insectary plants.

All aphids are bad, but invasive black citrus aphids can kill your orange tree.


Well, not exactly.

Black citrus aphid identification

Also known as oriental citrus aphids and brown citrus aphids, they get the different color names because they change color as they develop. Adult black citrus aphids are black and shiny. Like other aphids, they can be winged or wingless. Nymphs are reddish-brown. And there are no eggs unless they live in Japan.


Black citrus aphid lifecycle

All black citrus aphids are female, and all of those females give birth to live young unless they live in Japan. For some bizarre reason, black citrus aphids occurring in Japan do lay eggs. In either case, those populations can explode in record time. It is estimated that a single black citrus aphid can produce more than 4,400 offspring in three weeks. Those offspring can start reproducing on their own when only one week old. You can see how things could quickly get out of hand. The network effect of all that reproduction can result in 600 billion aphids in a single season, all starting with one aphid.


Managing black citrus aphids

One way to reduce aphid problems is to only feed nitrogen to plants at the appropriate times and avoid shearing citrus trees. Shearing and nitrogen both stimulate vulnerable new tip growth. Also, ants protect aphids. You can eliminate that protection by wrapping the trunks of citrus trees with sticky barriers. You can also use sticky sheets hung in your citrus trees to monitor for winged aphids and other pests.


Natural predators, such as ladybugs, and parasitic wasps will help reduce aphid populations. You can attract these beneficial insects to your garden by installing insectary plants, providing water, and avoiding the use of broad-spectrum pesticides.


A powerful stream of water from your hose can dispatch large clusters of aphids which are then unable to return to the tree, but this treatment won’t get them all, and it only takes one. Insecticidal soap can also be used, but that treatment is only effective on the aphids it touches.


Monitor your trees regularly for signs of black citrus aphids and report any potential sightings to your local County Extension Office right away.

Citrus sadness is not a case of lemon tree depression. But citrus growers around the world are pretty sad about this plant pandemic.

Citrus sadness, more scientifically known as citrus tristeza virus (CTV), is the costliest citrus virus. It has killed more than 80 million citrus trees and made an added 40 million more citrus trees useless for growing edible fruit. And it spreads quickly.


First seen in South America in the 1930s, this disease was called “tristeza” which means sadness in Spanish and Portuguese. Citrus sadness attacks several citrus species and passion flowers (Passiflora gracilis).


Symptoms of citrus sadness

Symptoms of citrus sadness vary depending on the infected plant species. They are generally grouped into one of three categories: decline, seedling yellows, and stem-pitting. In each case, viruses populate the phloem, causing chlorosis, vein clearing, leaf speckling, fruit dwarfing, and stem dieback.

If you suspect citrus sadness has found its way to your tree, contact your local County Extension Office right away.

​Cucurbit scab management

Prevention is your first line of defense with any disease. Buying certified disease-free seeds, seedlings, and mature plants can help keep spores out of your landscape. Spores are spread by insects, tools, clothing, splashing rain, and the wind, so you’ll still have to be on the lookout.


You can prevent cucurbit scab from occurring with some simple cultural practices:

• Remove and dispose of any infected plants.
• Do not leave old vines or seeds in the field where spores can overwinter.
• Use three-year crop rotations for all of your cucurbits.
• Apply common fungicides, such as fixed copper, when conditions favorable to this disease are present.

​I hope this information helps you keep your cucurbits healthy and productive.

There are actually three different moth species called winter moths in the U.S. In addition to our invasive Operophtera, there are also the native Bruce spanworms (O. bruceata) and linden loopers (Erannis tilaria). These native species feed on deciduous hardwoods.​

Those buds provide her babies with plenty of food, but that’s bad news for the tree. After burrowing into and feeding on new buds, winter moth caterpillars start feeding on leaves. When they get big enough, they spin silk strands in ‘balloons’ that carry them to neighboring trees. Caterpillars continue eating leaves until mid-spring when they abandon their tree and enter the soil where they will pupate. In late autumn and early winter, adult moths emerge, and the cycle continues.

Anyway, sharp-nosed leafhoppers (Scaphytopius magdalensis, also known as Platymetopius magdalensis) are invasive pests found throughout the U.S. They feed on cranberry, huckleberry, and other members of the heath family (Ericaceae), as well as soybeans, potatoes, willows, and grasses. This feeding doesn’t cause much in the way of damage besides stippling, but these pests are also vectors for blueberry stunt disease, soybean bud proliferation, and western X-disease.


Sharp-nosed leafhopper identification

Sharp-nosed leafhoppers are small, brown, and quick. They are narrow and less than one-quarter of an inch long. Like other leafhoppers, they tend to hide until disturbed, then they leap to safety. Very often, leaf stippling and this sudden leaping are the only clues that leafhoppers have arrived. If you catch one on a yellow sticky sheet, you can see that they are brown with white markings on both body and wings. And they have pointy, anvil-shaped heads. Nymphs are off-white with dark, hourglass-shaped wingpads.


Sharp-nosed leafhopper lifecycle

Eggs are laid in leaf tissue, where they overwinter. A second generation is started in mid-summer. Wingless nymphs tend to emerge just as blueberry buds are beginning to open. Sharp-nosed leafhopper nymphs go through five instars before reaching adulthood.

Sharp-nosed leafhopper management

Sharp-nosed leafhopper feeding isn’t particularly damaging. The leaf stippling they cause can slow photosynthesis, but leaf stippling can also be caused by aphids, spider mites, thrips, and other pests, so it’s important to look closely and try to catch a specimen if you can. The real problem is the diseases these pests can spread as they feed. Yellow sticky sheets are the best way to monitor for sharp-nosed leafhoppers. If they become a problem, you may have to apply insecticidal soap.

Both lowbush (Vaccinium angustifolium) and highbush blueberries (V. corymbosum) are susceptible to the blueberry shoestring virus.


Blueberry shoestring virus symptoms

The leaves and stems of a plant infected with the blueberry shoestring virus are red and deformed. Young stems may show red streaking and leaves become significantly thinner than normal, hence the name. Ultimately, leaves become crescent-shaped and fruit production is all but eliminated.


Other symptoms of blueberry shoestring virus include an oak-leaf pattern of red surrounding leaf veins, flowers of infected plants tend to be pinkish-purple, rather than white, and discolored berries do not turn blue.

Blueberry shoestring virus lifecycle

The blueberry shoestring virus may take up to 4 years to start expressing itself. This allows the disease to spread silently as aphid vectors move from plant to plant, feeding and infecting. Since this disease is spread by aphids, monitoring for and controlling these pests is the best way to keep your blueberry plants healthy.


Infected aphids spread the disease as they feed. They also lay eggs at the base of blueberry buds where they overwinter. As spring temperatures begin to rise, the eggs hatch, and a new generation of infected aphids continues the problem. These eggs tend to hatch when temperatures reach 38°F, so that’s when you need to start treating blueberry plants for aphids.


Blueberry shoestring virus management

Natural predators, such as ladybugs, especially seven-spotted lady beetles, and parasitic wasps provide significant protection against aphid-borne diseases, so avoid using broad-spectrum pesticides. Also, starting with certified pest- and disease-free plants is always a good idea. Infected plants should be bagged and removed immediately. There is no cure for the blueberry shoestring virus.


To protect your plants against the blueberry shoestring virus, do your best to keep aphids under control.

If the tips of your blueberry stems suddenly start wilting, it’s probably blueberry tip borers. Blueberry tip borers (Hendecaneura shawiana) are the larvae of moths. These are not the same thing as blueberry stem borers (Oberea myops), which are a type of beetle.


Blueberry tip borer description

I couldn’t find photos that I could use, but these mottled brown moths look like they have a white saddle and their antennae tend to be long and thin. If you get your hands on one, you may be able to see that they have orange marks near the tips of their wings and a one-half-inch wingspan. The larvae are somewhat yellowish and the eggs are translucent.


Blueberry tip borer lifecycle

Eggs are laid on the underside of leaves. Once they hatch, larvae burrow into canes, usually within half an inch from the tip of the shoot. These larvae feed all summer while inside the plant and then overwinter in their protected space, before pupating in spring.


Managing blueberry tip borers

If new shoots suddenly start wilting, take a closer look. You may be able to see tiny pinhole entries. Tunneling and feeding by blueberry tip borers result in stem wilting and leaf browning, especially around leaf edges.


If you suspect blueberry tip borers, remove an affected shoot and cut it open lengthwise. If you see borer larvae, it’s a good idea to prune out any infested shoots. If you can catch the larvae between hatching and boring, you can apply Bacillus thuringiensis (Bt). Once inside a plant, these pests are pretty safe from whatever you might want to spray.


Like most other blueberry pests and diseases, this one is still mostly found on the East Coast. As more people around the world start growing blueberry varieties that need fewer chill hours, those problems will also spread, so be forewarned.

Symptoms of blueberry stunt

It should come as no surprise that stunting is the most common symptom of this disease. Closer inspection shows that infected stems have much smaller internodes [spaces between nodes] than healthy stems, which makes the plants look smaller than normal. Leaves may be cupped slightly downward and chlorotic leaf margins may be present.


Blueberry stunt disease cycle

As carrier sharp-nosed leafhoppers feed on blueberry plants, they allow stunt phytoplasmas to move from their host’s gut to your plants. Once inside a plant, these tiny beasties move to the sapwood, where they feed on sap, live, and reproduce.


Blueberry stunt control

Starting with certified disease-free rootstock is one way to reduce the odds of bringing blueberry stunt disease into your garden. Also, use yellow sticky sheets to monitor for signs of sharp-nosed leafhoppers and start treatments as soon as they are seen. Once a plant is infected with blueberry stunt disease, it must be removed and destroyed.


Luckily, so far anyway, blueberry stunt is only found on the East Coast. For now.

Unfortunately, this disease is spread by honey bees as they collect pollen. It can also be seed-borne, though this is rare. As far as I could learn, blueberry leaf mottle is currently only found in Michigan, Canada, and South Korea. Of course, things can change in a single day. Case in point, this virus has decided that blueberries are no longer their only host. Grapes are now on the menu.


Blueberry leaf mottle symptoms

True to its name, leaf mottling is the primary symptom of blueberry leaf mottle. Infected leaves are often lighter in color and smaller than healthy leaves and may be puckered or otherwise deformed. Stunting and dieback may also occur. Infected grapevines exhibit delayed budbreak, elongated fruits, and sparse fruit clusters.


How to manage blueberry leaf mottle

The kicker about this disease is that symptoms don’t appear until three or four years after the plant is infected. And there are no known treatments. This makes prevention your only option. To prevent blueberry leaf mottle from occurring in your garden, be sure to only buy certified disease-free rootstock. Infected plants must be removed and thrown in the garbage.


I hope your blueberry bushes stay healthy and productive.

You may not be able to see blueberry bud mites, but they can be devastating to your blueberry and huckleberry plants.

Commercial growers apply miticides directly after harvesting when blueberry bud mites are detected. Once buds have formed completely, the mites are safe from chemical treatments. Many of the miticides used against blueberry bud mites are not available to home growers. Those that are available require careful timing. Other options include pruning infested shoots and tossing those shoots in the garbage. Predatory mites and predatory thrips provide a little protection, so avoid using broad-spectrum pesticides and plant a few insectaries near your blueberries.


Blueberry bud mites are currently only found east of the Rocky Mountains, but that can always change as more people grow blueberries and huckleberries on the West Coast.

plant-food.htmlUnlike gravity watering systems that use inverted bottles that drain into the soil, pot irrigation uses moisture tension to irrigate plants.


What is an irrigation pot?

Irrigation pots are unglazed clay jugs that have been buried in the soil with only the upper edges above the soil line and covered with a ceramic lid or plugged with a cork. Water can seep through these unglazed pots. If the soil is already wet, the water stays in the pot. If the soil is dry, plant roots and the soil pull water from the jug, providing a steady source of water. Over time, plant roots will grow toward and wrap around the irrigation pot.


History of irrigation pots

Irrigation pots or “ollas” have been used for thousands of years. Archeologists have found them around the world, from South America to China. I can imagine that carrying water every day was quite a chore. Being able to fill irrigation pots every few days instead of watering daily would be a big attraction. In fact, I wish I had heard about pot irrigation while I still had my raised beds! I would’ve put one pot right in the middle of each 4x6 bed and saved myself a lot of time and water.


​How to use ollas

Inexpensive unglazed ceramic jugs and pots are often available at yard sales and thrift stores. They can be a bit pricey in retail stores, but you have to ask yourself what your time and water are worth. You can also use standard ceramic planter pots. Simply plug the drainage hole with a cork and use the saucer as a lid. If you want to, you could create a system of connected ollas. But that’s beyond this post.


Ollas can be filled every few days, depending on the weather and the size of your irrigation pot. Put simply, bigger pots need to be filled less often, will water larger areas, and take up more space. Generally speaking, a 3-gallon pot will water a three-foot diameter area for 3 to 7 days. In 2013, Ecology Action used five 5-gallon ollas for a 100-square-foot garden plot. Their ollas had caps that reduce evaporation and collect rain.


The important thing to keep in mind when using ollas is that they water the subsoil. Seeds and new transplants will need extra water at the surface to get established. Also, plants should be installed at least one foot away from the olla to keep young roots out of the heavily saturated soil.


Benefits of pot irrigation

Pot irrigation is said to conserve 50% to 70% of your irrigation water. That’s a lot of water! Watering from the soil also significantly reduces fungal diseases and you don’t have to mess with the garden hose as often. You can also add fertilizer to your olla, allowing plant roots to absorb those nutrients at a gentle pace while preventing up to 66% nutrient loss due to evaporation and inaccessibility. Finally, clay pots are earth-friendly. There are no plastics or chemicals to leach into your soil or food supply. You may have to monitor for slugs, however.

Crazy ant lifecycle

Crazy ants are not as well-organized as other ant species. Instead of building nests, they live in piles of plant debris, tree cavities, under rocks, and in electrical equipment. Very often, as temperatures drop, these pests move indoors and into your stereo. Instead of a single queen lording over her countless minions, crazy ant colonies tend to be small with several queens. As many as 20 queens may be hiding under a rock. And these single colonies network with neighbors. A single collection of a few hundred crazy ants can quickly become a “supercolony” of hundreds of millions of ants.


These crazy ants search far and wide for food. They do it quickly, and they eat pretty much anything: living or dead insects, nectar, honeydew, seeds, plants, grease, and sugar are just a few of the snacks these pests will bring home for the colony.


Crazy ant control

First found only in southern states, these pests have moved northward to Massachusetts and west to California and Hawaii. Controlling crazy ants is difficult because of their networked colonies. Standard ant baits and over-the-counter pesticides do not work against crazy ants.


If your house, garden, or vehicle are infested with crazy ants, call a professional exterminator. In 2008, the Environmental Protection Agency authorized the use of fipronil against these pests. Unfortunately, fipronil is considered one of the worst causes of colony collapse disorder in honey bees. It’s best to leave those treatments to the pros.