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Garden Tips

Archive for September 2009

NEW APPLES

written by

Marianne C. Ophardt

WSU Extension Faculty

for the Tri-City Herald, Kennewick, WA

I love fall. It’s when tart , juicy apples are ready for harvest. Imagine my dismay when the only apple varieties I could easily find when I moved to Washington in 1980 were Red and Golden Delicious. My “apple palate” was developed in the northeast part of the country where apples had more flavor, more tart balanced with sweetness. Red Delicious apples just didn’t measure up for me, but it was the predominant apple found in local orchards and grocery stores.

However, market preferences change with time and the Red Delicious trees in many Washington orchards have been replaced with newer varieties, such as Gala, Fuji and Granny Smith. Within the last several years, even newer varieties, such as Cameo, Honeycrisp, and Pink Lady, have also made an entrance. Soon you may come across SweeTango, one of the newest apple varieties on the market.

SweeTango is hitting market shelves this week in a few big cities, like Seattle. This new variety was developed at the University of Minnesota by the same breeders that developed Honeycrisp. Trademarked by the University of Minnesota, the breeders are hoping SweeTango will be as successful as Honeycrisp, one of SweeTango’s parents..

SweeTango is a blush type apple with a deep red blush over a yellow background. I haven’t had the chance to taste it yet, but it’s reported to be crispy, “juicy and sweet with hints of fall spices, balanced by vibrant acidity.” David Bedford, one of the breeders that developed SweeTango, says it has the “same wonderful crispy texture of Honeycrisp and even more flavor than its parent.” If you don’t find one in Seattle, you’ll probably have to wait until 2011 or 2012 when more SweeTango trees come into production and their fruit becomes available nationwide.

A new apple variety from Minnesota, why not from Washington? After all, Washington state is the top apple producer in the country and at least 45 per cent of the apple varieties in production here are considered passe. Be patient, you will probably see one or more new outstanding varieties being released from WSU within the next year or so.

Traditional apple breeding takes time. Last year in the WSU apple breeding program over 18,000 new hybrid seeds were produced from 18 crosses. Some 20,000 seeds from the crosses made the year before were planted and 14,000 seedling from the 2005 crosses were budded onto dwarfing rootstock. Getting closer to testing and tasting, over 6,200 seedling were planted in evaluation orchards in 2008 and the best selections from earlier trials were propagated for regional trials. They’re also testing “elite” selections in grower trials.

What do breeders look for when developing a new apple? Obviously they want an apple that has super eating quality, one with the right firmness, crispness, juiciness, and a balanced sweet-tart flavor. It must also be attractive with desirable color, size, and appearance. On the production side, a stellar apple variety must bear early, produce well, not be prone to sunburn, and have disease resistance. In addition, it must store well and taste great when it comes out of cold storage. It’s a lot of work, but before long there will also be new unique WSU varieties being released for growing in central Washington.

By the way, my favorite apple varieties are Empire and Ida Red, not usually available in our region, but I am becoming a fan of Cameo, Honeycrisp and Pink Lady.

Published: 9/12/2009 11:37 AM

BARBERRIES POSE A THREAT

written by

Marianne C. Ophardt

WSU Extension Faculty

for the Tri-City Herald, Kennewick, WA

The “terrorist” or invasive plant threat level has been raised to “red.” They’re popular plants in our landscapes and seem so innocuous. It’s shocking to find that common ornamental shrubs that have been around for years are a threat to the native plant and wildlife in our country.

One of these invasive “terrorists” is Japanese barberry (Berberis thunbergii), a native of Japan. It first infiltrated this country in 1875 when some of its seeds were sent to the Arnold Arboretum in Massachusetts. In 1896, Japanese barberry shrubs were planted at the New York Botanic Garden. It was later promoted as a substitute for the common barberry (Berberis vulgaris), also a non-native from Europe.

The common barberry was used by European settlers for creating hedgerows, as well as for making jam and dyes. Unfortunately, common barberry was discovered to be an alternate host for black stem rust, a devastating fungal disease of wheat in this country. After two serious wheat stem rust epidemics in the early 1900s, the U.S. Department of Agriculture initiated a program to eradicate common barberry in wheat producing states. By 1933, more that 18 million barberry shrubs had been destroyed. It wasn’t easy. This European native shrub, planted by European settlers, had escaped its original planting sites and had become invasive, just like it’s Japanese cousin has done more recently.

The eradication program was a success with 98 per cent of common barberry shrubs eradicated in the targeted areas by 1972 and in 1981 this successful federal program was discontinued. If it hadn’t turned out that the Japanese barberry was stem rust resistant and didn’t pose a hazard to wheat, it might not have become a popular landscape shrub. Rust resistant, it became a replacement for common barberry. Because of this, plant breeders have worked with Japanese barberry, creating numerous colorful cultivars available for today’s landscape plantings.

Over the years, the Japanese barberry’s popularity has grown. Unfortunately, that’s not good news. Jil M. Swearingen, M.S., the Invasive Species Management Coordinator for the National Park Service, points out that Japanese has become invasive in twenty states in the northeastern U.S. Swearingen notes that Japanese barberry forms dense thickets in many different natural habitats, including canopy forests, open woodlands, wetlands, pastures, and meadows. By displacing native plants, the Japanese barberry reduces wildlife habitat and forage.

How does it spread? You know those clusters of little bright red berries that develop after the pale yellow flowers fade in the spring? Birds and small mammals eat the berries and spread the shrub via the seeds in the berries. The shrubs also multiply from parts of roots left in the soil when the plants are removed.

Is it a problem in Washington? Not so far. Japanese barberry is not currently on noxious weed lists in Washington, however it has the potential of becoming a problem in some areas of the state. It has become a problem elsewhere because it’s very adaptable. It prefers full sun, but is shade tolerant. It’s drought resistant, but will also grow in wetlands.

Should we stop selling, buying and planting Japanese barberry here? I think in our local area with the arid climate, it should not be considered a serious threat. Personally, I’ve never been a fan of Japanese barberry. I don’t like plants with red-brown leaves and I can’t abide with any spiny, thorny shrub, except for roses.

Published: 9/5/2009 11:30 AM

PRAYING OR PREYING MANTIS?

written by

Marianne C. Ophardt

WSU Extension Faculty

for the Tri-City Herald, Kennewick, WA

I noticed a large green mantis hiding amongst the leaves of my potted herbs. He was patiently waiting for a large grasshopper to come to him. The grasshopper came closer and closer and then suddenly the mantis pounced, trapping the grasshopper with its forelegs and taking a big bite out of the still struggling captive. I just couldn’t keep watching this gory display, even if the grasshopper had been nibbling on my herbs.

The two species of large green or brown mantises that are sometimes found in local yards and gardens are aliens. These non-natives, the Chinese mantis and the European mantis, were introduced into this country about 75 years ago to provide natural control of crop insect pests. These vicious predators didn’t turn out to be good pest managers, but the mantises have prospered and spread throughout the U.S. and Canada. While not very effective in controlling pest populations, gardeners still buy mantis egg clusters for release in their gardens.

Why aren’t they effective? As vicious “meat” eaters, the mantises eat insects, but they attack both bad guys, like aphid and moth pests, and good guys, like bees and spiders. Another reason for their lack of effectiveness is that mantis populations are slow growing, making it difficult for them to keep up with quickly burgeoning pest populations.

One reason mantis populations grow so slowly is that there is only one generation a year. The other reason is that mantises are territorial and cannibalistic. Oh my! This nasty predilection prevents a buildup of the mantis population. If gardeners try to help out by placing numerous egg cases here and there, the mantis numbers still don’t seem to grow significantly larger. That’s because the hatching mantises either eat each other or quickly move to where there is enough food and places to hide.

Hiding is what mantises do well despite the rather large three inch elongated body of the European mantis or the even larger Chinese mantis. Their lanky green to brown bodies easily blend in with plant leaves and stems.

In the fall, female mantises lay 30 to 300 eggs, enveloping them within a frothy gummy substance and gluing them to plant stems or other objects. The gummy substance turns hard, protecting the eggs over the winter. The adults die a little later, leaving only the eggs to survive the winter. In the spring, the eggs hatch and tiny baby mantises emerge from the tan colored shingled egg cases. The babies or nymphs eat and grow, molting numerous times until they reach maturity.

While the mantises that gardeners like me encounter are usually the introduced aliens, there is a native species found in the wild sagebrush areas of eastern Washington. The native “ground mantis” is gray and about one inch long.

How did mantises get the common name of praying mantis? That’s simple. When they lie in wait for their prey, they hold their front legs together at an angle that makes them look like they’re praying. I think they look like they’re rubbing their “hands” together in anticipation of dinner. Maybe they should be called preying mantises instead.

Published: 8/29/2009 11:25 AM

ALL IN THE CUCURBIT FAMILY

written by

Marianne C. Ophardt

WSU Extension Faculty

for the Tri-City Herald, Kennewick, WA

Knowing when and how to harvest members of the “cucurbit” family can be a bit tricky. This garden veggie family includes watermelons, cantaloups, pumpkins and winter squash.

Gardeners can use a combination of indicators to tell when their watermelons are ripe for the pickin’. It’s important to harvest watermelons only when they’re fully ripe, because they don’t get any sweeter after picking. The first sign of maturity is the curly vine tendrils close to a particular fruit turning from light green to dry and brown. As the fruit matures its skin becomes rougher and harder to pierce with a fingernail.

While some gardeners still insist on thumping their watermelons and listening for a hollow sound, the color of the bottom spot where the melon touches the soil is more reliable. As the fruit ripens, the bottom spot changes from greenish white to a buttery yellow or creamy white.

The ripeness of muskmelons and cantaloupes with netted skins is a little easier to determine. These melons are ready for harvest when they “slip” or are easily pulled off the vine. Other indicators include feel, color, and aroma. The netting becomes rougher and the skin between the netting changes from green to yellow, golden orange, or tan. The flower end of the fruit (the end opposite of the stem end) will be slightly soft. Finally, a good sniff of a ripe melon will reveal its tantalizing aroma. Like watermelons, cantaloupes don’t increase in sweetness after picking, but will soften a bit and develop better flavor if held at 70 degrees for several days.

There is no trick involved in telling when a pumpkin is ripe. When its skin turns hard and uniformly orange (except for some specialty varieties), it’s ready. It’s important to harvest pumpkins before a hard frost because the freezing temperatures can damage the skin and lead to rot in storage, although they usually can tolerate a light frost without trouble.

Pumpkins are “picked” by cutting them from the vine, leaving at least a three to six inch portion of stem attached to the fruit. Handle carefully to avoid scratching and bruising. Do not carry them by the stem. Wash off dirt with clean water and then “cure” the pumpkins. (Some gardeners like to wipe them with a ten per cent bleach solution or diluted household disinfectant to help protect against rot before curing them.)

Curing toughens the skin and allows for longer storage. To cure the fruit, place them in a warm (about 80 degrees) location for about a week or two and then store in a cool, dry place. All is not lost if your pumpkins haven’t turned completely orange by the time frost kills the vines. The curing process may encourage mostly green pumpkins (those just starting to develop some orange color) to turn orange.

Pumpkins are easy, but it’s more difficult to tell if the many other types of winter squash are mature and ready for harvest, especially if you’re not familiar with their mature color and size. Refer to the variety description to insure the fruit has reached the typical size and color for that variety. Also, their stems should be hard and the skin difficult to puncture with a fingernail. Like pumpkins, they’re cut from the vine, washed and cured.

Knowing when to harvest the cucurbit family may be a bit tricky, but there’s no trick involved in enjoying what we harvest. Yum!

Published: 8/22/2009 10:43 AM

WHAT’S BUGGING YOU TODAY

written by

Marianne C. Ophardt

WSU Extension Faculty

for the Tri-City Herald, Kennewick, WA

What’s bugging you? An entomolgist will tell you that all bugs are insects, but all insects are not bugs. “True bugs” belong to a particular order of insects called Heteroptera. True bugs have piercing, sucking mouthparts that allow them to feed on plant sap or animal body fluids. True bug adults typically have a flattened body and when at rest their wings form an X-shaped pattern on their backs.

One group of true bugs is referred to as seed bugs because they feed on the seeds of plants. Most are relatively small, no more than one-quarter to one half inch in length, with narrow, elongated bodies. There are both native and introduced species of seed bugs that feed on plants in our area. Their appearance varies from species to species, with most being an indistinct gray to brown color.

Many seed bugs give off an offensive odor when threatened or crushed and a few may even “bite” (actually they pierce the skin with their sucking mouthparts). In our area there are seed bugs that feed on sagebrush, birch and sycamore trees.

Because seed bugs can be present in large numbers in a yard and garden, they may cause concern. However, they aren’t considered a plant pest since they feed predominantly on the seeds of plants. It’s when seed bugs come indoors that they can become a problem.

This past week an area resident brought in a sample of a newly introduced exotic species of seed bug known as the tuxedo bug (Raglius alboacuminatus). His family was unhappy because a number of these tiny bugs were invading their home. Seed bugs don’t enter homes to harm people or pets or to infest food or clothing. They’re simply lost. Because the bugs are small, they easily enter buildings through small openings such as those found in vent screens, around window and door framing, and other openings.

Control is most easily achieved by vacuuming up the bugs and then disposing of the vacuum bag in the outside garbage can. Look for places they may be entering the home and try to exclude them in a practical way, such as with caulking or screening.

Stink bugs are another true bug found causing problems in local gardens. Both the Say stink bug (bright green with orange around the bottom edge) and the consperse stink bug (light brown)

are about one-half inch long, roundish and shield-shaped. While sucking plant sap, the stink bugs introduce saliva into a plant. The toxins in this saliva can cause plant reactions, such as the cloudy white spots found just beneath the skin of ripe tomatoes. Stink bugs also cause problems with their “stink” that can give an unpleasant taste to raspberries and other small fruit they feed on.

To help control stink bugs in the garden, remove nearby weeds that serve as overwintering hosts. Continue to practice good weed management during the growing season in and around the garden area. Sprays of insecticidal soap may be helpful if applied directly to the bugs when they are present. Check in the evening for them on garden plants and nearby host plants.

So is anything else bugging you?

Published: 8/15/2009 10:31 AM

MASTER GARDENERS HELP WITH GARDEN PROBLEMS

written by

Marianne C. Ophardt

WSU Extension Faculty

for the Tri-City Herald, Kennewick, WA

Having a garden or landscape problem? WSU Extension Master Gardener volunteers are ready and willing to help you with them. All you need to do is ask and they’ll try and help you determine the cause of the problem and recommend a research-based solution. This service is available to everyone in Benton and Franklin counties at no charge. Because the number of Master Gardener volunteers are limited and there are so many folks with plant and insect problems, the volunteers staff clinics where you can come to them with your questions… or you can call them at the Benton County WSU Extension office. (I’ll tell you where and when they’re available later.)

It’s been a tough summer for gardens and gardeners. The WSU Extension Master Gardeners have been busy helping diagnose scads of problems. You might be curious to know the current “top five” problems that they’ve been seeing in the clinics:

1. Leaf scorch is characterized by crispy brown edges on leaves of trees and shrubs. The complaint is most common on trees and shrubs planted within the last several years. Leaf scorch tells the Master Gardeners that the leaves aren’t getting enough water, but a lack of adequate water is just one of the causes. It’s also often related to how it was planted and a lack of root growth after planting.

2. Excessive lawn thatch becomes a problem in mid-summer when temperatures get hot and large areas of lawn start to turn brown no matter how water is applied to the lawn. When samples are brought into the Extension office clinic, the presence of thatch can be confirmed.

3. Blossom end rot where the bottom of a tomato develops a brown, leathery area. We discussed this here already a month ago, but it’s still plaguing gardeners. This is a calcium deficiency within the fruit, but is usually not a caused by a lack of calcium in the soil. This is most often related to watering problems, either too little or too much… or fluctuating between the two. Even soil moisture is the best prevention. Other veggie garden problems are heat related woes, such as bitterness in cucumbers, lack fruit set, and uneven ripening of tomatoes

4. Squash bugs are elusive, but they’re the most likely cause of the suddenly wilting and dying of squash, cuke, and melon plants, especially if the soil moisture is adequate. At dusk, check at the base of the plant and vines. Although, it’s important to note that these vines will normally wilt during mid-day extreme heat and then perk back up as temperatures cool off in the evening.

5. Lawn and garden weeds are a common problems seen by the Master Gardeners. The two most common ones in the clinics right now are crabgrass and bentgrass.

Published: 8/8/2009 10:11 AM

IT’S HOT FOR PLANTS TOO

written by

Marianne C. Ophardt

WSU Extension Faculty

for the Tri-City Herald, Kennewick, WA

Can you believe the sweltering weather our region has been enduring? With predictions of continued intense heat, health experts have been warning us about the dangers of this weather and telling us what precautions to take… drink plenty of water, don’t over exert yourself, and try to stay indoors.

Hot weather is not only stressful to us, it’s also stressful to our garden plants. Unfortunately, there’s not a lot we can do to help our plants “beat the heat” other than checking the soil and making sure it stays moist.

You may think you’re applying plenty of water to your plants, but the water may not be reaching deep enough. To check, I recommend about six hours after watering that you use a trowel or shovel to check the soil for moisture.

When checking the soil moisture, consider that soil should be moist to a depth of 24 to 36 inches for trees and large shrubs, 18 to 24 inches for moderate sized shrubs, 12 to 18 inches for small shrubs, perennials, vegetables and annual flowers. Especially during this long spell of extreme heat, you’re likely to find that you need to irrigate your lawn, landscape and garden for longer periods of time and more frequently to keep the soil moist.

Here are some other ways to help your plants cope with the hot weather:

1. Apply an organic mulch to decrease the evaporation of moisture from the soil surface. An adequate layer of organic mulch can reduce evaporation from the soil by as much as 70 per cent.

Organic mulches, like bark and compost, protect plant roots from damaging temperatures by reducing soil temperatures below the surface as much as 10 degrees. Rock mulches absorb heat, raising soil temperatures in the root zone. In addition, rock mulches hold and then radiate heat at night, increasing plants’ water needs. Light colored rock mulches reflect light back onto plants, also causing additional water demands on a plant.

2. On a hot, dry summer day a mature tree can use as much 100 gallons of water per hour or 2400 gallons per day! Because trees use more water during hot weather, you should apply more water. Trees and shrubs have deeper roots than your lawn and need deep watering. Short, frequent irrigation of the lawn can not provide adequate amounts of water to your trees. It’s bothersome, but you should hook up a soaker hose and use it to give your trees and shrubs a deep watering once a week during the summer.

3. When you deep water your trees, keep in mind that the water absorbing feeder roots of established trees are not located at the base of the trunk. Instead, they’re located from the drip-line of the canopy outward, extending as much as 1.5 the diameter of the canopy past the drip-line.

4. Container gardens and raised bed plantings dry out more quickly than “in-ground” plantings because of the reduced soil volume and the soil mixes. Check the soil in these situations and water when needed. You may find you’ll need to water more than once a day during the hottest times of the summer.

It’s looks like the hot weather is going to continue, so make sure both you and your plants have enough water to drink!

Published: 8/1/2009 10:01 AM

UPSIDE DOWN TOMATOES

written by

Marianne C. Ophardt

WSU Extension Faculty

for the Tri-City Herald, Kennewick, WA

I’ve been asked what I think of the upside down planters “as seen on tv” and even sold in local stores. Having not succumbed to the hype, I have to rely on my knowledge of plants and what other gardeners have told me about their experiences with these planters.

If you stick a plant in the bottom of a container and expect it to grow straight downwards as shown in the deceptive ads, you’re fooling yourself, not the plants. Plants simply won’t grow that way. In response to gravity, the plant roots grow downwards and shoots grow up. If you try to grow a plant upside down, the stems will turn upwards and the roots will grow down. This response to gravity is a phenomenon known as “geotropism” or “gravitropism.”

What gardeners can’t see in their upside down planters is the roots responding to gravitropism. Roots will be concentrated near the bottom of the planter and not growing upwards and filling the vertical tower of potting soil.

Now, let’s review comments from folks actually growing tomatoes in these planters. The first thing to know is that once you get the planters assembled and filled with moist potting mix they’re extremely heavy. Very sturdy hardware and strong support is required wherever you hang them. Users advise hanging the planters before watering them, as they become even more weighty after watering.

Users also note that during hot summer weather it’s hard to keep these planters watered. The planters tend to dry out quickly, especially if located in full sun. Many found it difficult to keep the plants alive unless they could water the planters several times a day. Others noted the problem of the water running out the bottom, a common problem with many hanging planters.

Perhaps the most critical reviews come from gardeners that went to all the trouble of planting, hanging, watering, fertilizing and caring for their upside down tomato planters but ended up with none or very few tomatoes. To be fair, some gardeners have been successful with the upside down planters. It seems that about half the gardeners using them have some success and the other half don’t. So here are what gardeners say about their good and bad points:

Good Points

– a novelty and something fun to try

– allow growing tomatoes where space is limited, such as on a patio or balcony

– no need to dig in the dirt, bend over to pull weeds, or cage the tomatoes

– ripe fruit are easy to find and pick

Bad Points

– extremely heavy (about 60-70 lb.) when filled with potting soil and water

– needs to be watered frequently (two times a day or more) during hot, sunny weather

– hard to water, you may need a ladder or a pulley system to assist in watering

– plant roots can get very hot, stressing plants

– lack of success… many gardeners’ note plants don’t produce a bountiful harvest or plants rot at the base of the stem and die

One gardener who had success noted that the upside down planters needed more watering and care than typical in-ground tomatoes. So much for the “easier” aspect of growing in these planters. Based on what I’ve heard, I’m pretty sure I won’t be buying any of the upside down planters, but they might be fun for others to try. Good luck.

Published: 7/25/2009 9:52 AM

BECOME A SMART WATER MANAGER

written by

Marianne C. Ophardt

WSU Extension Faculty

for the Tri-City Herald, Kennewick, WA

I’m not sure many of us could get to the million dollar level in the “Are You Smarter than a Fifth Grader?” game show, but we definitely could go back to “school” to become smart water managers. Here are some short lessons on how to water your yard and gardens more intelligently.

1. DON’T SET IT AND FORGET IT: If your irrigation system runs on a timer, don’t set your controller in the spring and then forget it. During different parts of the growing season, plants have different water needs. They need less water in the cooler parts of the season, and more when it’s hot… like now! Adjust your timer for the time of year and your plants’ needs.

2. OBSERVE AND ADJUST: Adjust and fix sprinkler heads so you aren’t watering sidewalks, driveways, and building walls. If you have dry spots in your lawn, check to see that those areas are receiving adequate water. You can do this by placing straight sided containers (such as soup cans) in both the dry spots and areas that aren’t dry within a zone. Run that zone for a set amount of time and then compare the amount of water in each of the cans. If the depth is significantly different, you need to troubleshoot and fix the cause.

3. AVOID RUNOFF: Water running off down the street isn’t helping your yard and garden. If you get run-off soon after your sprinklers go on, find out why. Perhaps your system applies water faster than the soil can absorb it. This is often a problem on slopes. This can be avoided by “cycling” which involves splitting the irrigation time into two or three shorter application times. Water should be turned on until run off starts and then stopped. Allow time for the water to soak in and then turn the water on again for the same amount of time. Keep repeating until the soil is moistened to a depth of at least eight inches.

4. WATER DEEPLY, LESS FREQUENTLY: Deep watering consists of moistening the soil to a depth of 8 to 12 inches for lawns and 18 to 24 inches for perennials flowers, shrubs, and trees. If you only apply a little water to your lawn or garden every day, the plants will not develop deep roots. As a result, the roots will stay near the top of the soil where they can get water. Watering deeply, encourages deeper, more extensive root systems that can take advantage of water and nutrients deeper in the soil. (Take note: Do not abruptly change your watering practices from shallow to deep watering in the hot part of the summer. Gradually change to deeper, less frequent irrigation.)

Published: 7/18/2009 9:44 AM

ROOT WEEVILS NOTCH PLANTS

written by

Marianne C. Ophardt

WSU Extension Faculty

for the Tri-City Herald, Kennewick, WA

Tomato hornworms gorge themselves on tomatoes. Colorado potato beetles devour potatoes. The corn earworm feasts on corn. Root weevils nosh on over 100 plant species including lilac, strawberries, peony, rose, raspberry, phlox, rhododendron, azalea, cotoneaster, Euonymus, clematis, yew, many different weeds, and more. The numerous small (no more than one-eighth of an inch wide) notches are characteristic of the feeding damage caused by these snout-nosed beetles, commonly called root weevils. They feed only on the edges of leaves because their snouts gets in the way, making it impossible for them to eat holes out of leaves.

Root weevils are nocturnal feeders, so these culprits are usually not found when sought during the day. If “seeing is believing,” you can go out on a summer evening after dark with a flashlight to look for them. During the day the root weevils hide under mulch, plant litter, or in crevices in the soil.

There are numerous different types of root weevils, but the two most commonly found in our area are the black vine weevil (BVW) and the strawberry root weevil. The adults of both have a shiny brownish-black to black oblong body. Their head elongates into a snout and their abdomen is covered by hard wing covers with parallel ridges. The BVW is up to one-third inch in length, but the strawberry root weevil is only about one-quarter inch or less in length.

The notching caused by adult root weevils is often considered only cosmetic, not causing significant harm to the plant. However, a large population of root weevil larvae do injure and kill young woody plants by feeding on the roots and the bark of stems close to the soil.

If you want to manage a root weevil problem without traditional chemical pesticides, you can utilize several approaches:

– Go out after dark and hand pick the adults off the plants and drop them in a container of soapy water or try placing a white cloth beneath each plant and gently shaking the branches. The root weevils will drop onto the cloth.

-Trap root weevils by tying corrugated plastic or cardboard (with the grooves facing inward) around stakes and laying them in the garden. They will hide in the corrugation groves during the day. Open up the traps and dispose of the roots weevils regularly.

– In some areas, parasitic nematodes applied as a drench can be used to manage a root weevil problem, but they work best when applied to very wet soils in late summer or early fall. Experts are doubtful that success can be achieved with these nematodes in our region .

Earth-friendly bio-insecticides include Beauveria bassiana (an insect killing fungus), azadirachtin (an extract from the neem tree that disrupts insect feeding), and spinosad (a soil bacteria byproduct). Chemical pesticides that will work include acephate, cyfluthrin, bifenthrin, and malathion. If applying materials to food crops such as strawberries, be sure the crop is listed on the pesticide label. Not all materials mentioned here are safe and labeled for use on food crops.

To be effective, both bio-insecticides and chemical insecticides should be applied as a spray when new foliar notching is noticed when the adults first emerge in early summer. The weevils feed for three or four weeks after they emerge before they start laying eggs. Each BVW female can lay 200 to 500 eggs and all BVWs are female! Applying controls early in the season, will help reduce a potentially burgeoning population.

Published: 7/11/2009 9:06 AM

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