Category: Pest Management

Thrips continue to be a problem through the summer months. They can infest a variety of flowering plants including hibiscus, hydrangea, and roses. Continue to look for signs of damage such as curled leaves, stunted growth, and white streaks on the foliage. Monitor your plants with a simple beat test. Tap the branch onto a sheet of white paper and look for small, thin, brown or orange thrips on the paper. Five or more thrips per beat may warrant spraying with an insecticide labeled for thrips, but first look closely for signs of the minute pirate bug, a natural predator of thrips. These small, black insects feed on thrips and also on pollen, so look for them on the flowers.

Beware of yellow jacket nests in the ground. These insects are beneficial when they feed on insect pests and are important pollinators, but when drought shrinks their food supply, they become dependent on trash, food crumbs, and sweet liquids found around our homes. They defend their food sources by stinging repeatedly at the slightest provocation. Keep your living areas clean of food debris and keep your trash and food containers covered.

Take the time to inspect your pine trees for pine sawflies. The larvae are an inch long and yellow-green with black dots. They consume all of the needles on a single branch before moving on to the next one. Small trees can be completely defoliated in a few days, so check them often. These insects are easy to remove by hand since they feed in groups. Horticultural oil can be used if the infestation is severe.

August is the time to monitor your garden for the presence of Oriental beetles. In the larval stage, the white grubs can be very damaging to plants as they feed on the roots of annuals, perennials, shrubs, and trees. Very similar to the Japanese beetle grub, the grub of the Oriental beetle can be identified by the pattern of bristles on the underside of the abdomen. Oriental beetle grubs have two straight lines of bristles; in Japanese beetles they appear in a “V” shape. You can monitor for the grubs by first observing the appearance of your plants. Oriental beetle grubs prefer plants indigenous to Asia such as flowering cherries and Chinese elm. Observe these plants for signs of stunted growth, which is the result of a loss of feeder roots. In the fall, look for grubs in the top few inches of soil. If there are more than a few per square foot, you may want to consider treating the area with a pesticide to control the grubs in the coming spring.

Be on the lookout for the Asian longhorned beetle. Native to China, the beetles were first spotted in Brooklyn, NY in 1997. They have since been detected in nearly every other state with port facilities. The large white grubs of this beetle feed on the heartwood of a variety of trees including maple, horsechestnut, boxelder, poplar, black locust, white mulberry, willow, and elm. They are particularly fond of sugar maple. The adult beetle can be seen from July to September and is easy to spot. The adult is an inch or more in length, glossy black with white spots, and long black and white segmented antennae. Besides the unmistakable appearance of the adult, look for signs on your trees such as sap flow, large holes, and sawdust. If you think you have spotted this pest, notify your state department of agriculture immediately.

Mid to late August is a good time to plant your salad greens such as lettuce and spinach. The shorter days and cooler nights of late summer and early fall make ideal conditions for a second crop of these cool season vegetables. The summer heat and drought conditions we’re experiencing this year have reduced the slug populations, so damage from these slimy pests should be minimal.

Hawthorn lace bugs plague many plants in the rose family including hawthorn, apple, cotoneaster, and firethorn. Adults have partially transparent wings with an intricate lacy pattern and opaque areas. Look for a whitish speckled appearance on the tops of leaves. The lower surfaces of the leaves are often discolored with excrement and cast skins of the developing nymphs. Use horticultural oil or a pesticide containing acephate and be sure to spray thoroughly on the underside of the leaves if large numbers of lace bugs are present.

During periods of dry weather, allow your lawn to go dormant to avoid turf diseases and to discourage weeds. If a green lawn is a must, water early in the morning and adjust your mowing height above two and a half inches.

Adult Japanese beetles feed on the foliage and flowers of over 300 different plants during the hot, summer weeks of July. These beetles have a metallic green body with reddish-bronze wing covers and are the size of a coffee bean. After mating, adult females lay eggs in turf. Dry soil conditions kill many of the eggs, so avoid watering lawns in July and August. To prevent serious damage, handpick the beetles daily in the early morning when they are less active and drop them into a bucket of soapy water.

Powdery mildew, a fungal disease that attacks the leaf surfaces of many flowers, shrubs, and trees, is a growing problem for dogwoods. Look for white powdery patches on the upper surface of new growth. This disease can cause the new growth to be curled and deformed, and often reduces the growth of very small trees. Loss of photosynthesis can also weaken the trees making them more susceptible to dogwood borers and canker diseases. To prevent powdery mildew, avoid heavy doses of nitrogen fertilizer, overhead watering, and excessive pruning. These practices can force tender new growth that is more susceptible to the fungus. Provide your trees with good air circulation, prune out dead wood, and place a thin layer of mulch over the root system. There are disease-resistant flowering dogwood cultivars available also such as ‘Cherokee Brave’ and ‘Sweetwater’.

Monitor your boxwoods for boxwood mites. These spider relatives are small, red, and slow moving. Yellowish stippling in a linear pattern appears on old foliage when mite populations are high. Beat test by tapping a stem onto a piece of white paper. Consider spraying with horticultural oil when the count exceeds twenty or more mites per beat. Do not spray if faster moving predatory spider mites, or small, jet-black mite destroyer ladybugs are present.

Monitor your plants for thrips. These very small insects may be found in the flowers and leaves of many plants. Thrips are orange to brown in color and they scrape leaves and petals with their mouthparts. Look for white streaks, curled leaves, and stunted growth. Find thrips by using the beat test. Gently tap a branch of the plant onto a piece of white paper and look for the thrips on the paper. If you count more than five thrips and the foliage shows signs of damage, you may want to consider spraying with a pesticide labeled for thrips. Before spraying, look for minute pirate bugs, small black insects that feed on thrips. They also feed on pollen, so look for them on the flowers. Refrain from spraying if these predators are present.

Look for bagworms toward the end of the month. Early detection is important; caterpillars are cleverly disguised and can quickly defoliate plants before they are noticed. Bagworms prefer evergreens such as arborvitae, cedar, juniper, and pine. Tap a branch over a sheet of white paper; look for small, green caterpillars with a small cone of plant debris attached to them. As they grow, they enlarge this cone until it is two inches long. Fully grown caterpillars anchor the bag they constructed to a branch before they become adults. Females fill their bags with as many as 200 eggs after they mate. Hand pick the bags before the eggs hatch to prevent damage. Remove the tough silken threads attaching the bags to the plant. If left on, they can girdle the branches as they grow. Spray infested plants with Bacillus thuringiensis as soon as the caterpillars hatch if bags are too numerous to remove.

Don’t overfertilize your plants. This practice encourages aphid populations which feast on the tender, new growth that results from the abundance of nutrients. Heavy, frequent fertilization usually results in nitrate contamination of ground and surface water as well.

Be aware of your plants’ watering needs during periods of drought. Plant roots, particularly those of shrubs and trees, extend one to two feet below the ground. Deep, infrequent watering is the best approach. This can be done by laying a hose at the base of your plants on a slow drip or programming your automatic drip system to run for an extended period of time at infrequent intervals.

Watch for signs of Seiridium canker on your leyland cypress. Increasingly popular in the southeastern states as a fast growing windbreak and privacy screen, this hybrid evergreen can be easily stressed by prolonged drought or extreme cold, making it susceptible to canker. Watch for signs of resin oozing from cracks in the trunk or branches, dark brown to purplish patches on the bark, and yellow-brown foliage above the canker. Keep plants healthy and vigorous. Aside from adequate moisture, leyland cypress need at least 15 feet of space to minimize competition with other plants; existing plantings can be thinned by removing some of the plants. During drought provide deep, infrequent watering and avoid overfertilizing. Prune wilted or discolored branches or tips, cutting back to a healthy part of the branch. Severely infected trees should be removed and destroyed.

Keep an eye out for a new scale that has been attacking spruce and other conifers. Fiorinia japonica, a scale similar to the more commonly known elongate hemlock scale, has been found in increasing numbers in the Eastern U.S. The males are white and the females are tan or grayish with a dark area in the center. Crawlers begin emerging in May and continue to emerge sporadically through September. Avoid using chemical pesticides to control this insect which will harm beneficial insects. If control is necessary, use horticultural oil when crawlers are present.

Keep algae growth down in your garden pond. Too much light and excessive nitrogen and nutrients create conditions for algae to flourish. Sources of nitrogen include fish and other animal wastes, uneaten fish food, and decaying plants. Provide your pond with good plant coverage to filter out excessive light and avoid overfertilizing the plants and overfeeding the fish that inhabit the pond.

Monitor your conifers for the presence of spider mites. Mites have piercing mouth parts and their feeding results in a stippled appearance on the foliage. Beat test plants by tapping the plant over a white sheet of paper. Look for small green, black, tan, or red mites about the size of a speck of pepper. More than 20 mites per beat may indicate serious damage. You can remove the mites with a jet of water from the hose or treat plants with horticultural oil. You can also buy predatory mites and release them to feed on the pest mites.

Now is a good time to check your ground cover junipers for off-color or brown foliage. These dead or dying branches may be infected with juniper tip blight and should be pruned out completely. This will remove some of the spores, improve the appearance of the plant, and increase air circulation. Junipers growing in the shade are more susceptible to this fungal disease and can be replaced with Siberian cypress, Microbiota decussata, a shade-tolerant evergreen ground cover that looks like juniper.

When the first temperate days of late winter arrive it’s time to check your hemlocks for eriophyid rust mites. These tiny, yellow mites are wedge shaped and cause needles to turn bronze and drop prematurely. The easiest way to check for these mites is a beat test. Place a piece of white paper under a branch and tap the branch vigorously. Use a magnifying glass to check the paper for the tiny pests that are no larger than pollen grains. Also check for the larger, fast-moving predatory mites that may be feeding on the eriophyid mites. If there are more than fifty eriophyid mites per beat test and you don’t see any predatory mites, you may want to treat the tree with insecticidal soap or horticultural oil.

Carefully examine the small branches of your apple, crabapple, and cherry trees for shiny, black masses that look like styrofoam. These are the egg masses of the Eastern tent caterpillar. Prune them out or scrape them off now. This will prevent the eggs from hatching into caterpillars in the spring and defoliating your trees.

Although some experts recommend the widespread use of dormant horticultural oil in late winter to control pests like scales, mites, and aphids, it is not considered a sound IPM practice. The best time to treat for these pests is in early spring when they have just hatched. Check plants regularly for pests and only treat those plants that are seriously infested. If you apply a dormant oil now, you will destroy any beneficial insects that may also be overwintering in your landscape.

This winter’s ice storm did serious damage to many trees. Take the time to evaluate the trees in your yard. If any of your trees lost more than half of their main branches, and especially if they lost their tops, you should consider removal. When a tree has many large wounds it is very difficult for it to heal, and it will probably never fully recover. The same can be said for trees that have started to lean due to storm damage. Young trees can regrow their root system if braced properly, but adult trees can’t and should be removed before they topple.

Wood ashes from your fireplace are high in potassium, a major plant nutrient that is easily leached from the soil by rain. Work your ashes into the soil around plants like peonies and roses that use a lot of potassium. Wood ashes can also serve as a lime substitute and will raise the soil pH to make other nutrients more available to plants. Wood ashes generally are a good soil additive, but be sure to spread them thinly and do not use them on acid-loving plants like azaleas and blueberries.

Winter annuals like chickweed, annual bluegrass, and wintercress produce large quantities of seeds in the first warm days of spring. Take the time to remove these weeds now.

When planting amaryllis bulbs this winter be sure to check for red sunken spots on the bulb surface. These spots indicate the presence of a fungus called Stagnospora curtisii which can cause leaf scorch. Infected plant tissue turns red, the leaves and stalks may become bent, and in severe cases the stalks dry up without ever producing flowers. A surface sterilization can prevent the infection from moving into leaves and flower stems as they emerge from the bulb. Soak your bulbs in a one percent bleach solution for one hour to contain the infection.

Now that freezing temperatures are upon us, be sure that pesticide containers are in good condition and stored properly. Never store your pesticides in an area that may reach freezing temperatures. If you have pesticides that are old or that you no longer need, call your county government to find out about disposal procedures.

Take advantage of winter downtime to get your gardening tools prepared for spring. Clean and sharpen your hoes for better and easier control of weeds. Sharpen or replace the blades on your pruning implements. Sharper blades give you cleaner cuts, which in the long run will give you healthier plants. This small amount of effort will save you time and energy in the spring.

Want to provide a wonderful service to the trees and woods around you while getting free holiday decorations at the same time? Remove English ivy that is growing up trees and structures. Once English ivy begins to grow upward it matures from the juvenile to the adult state and produces berries. Birds consume the berries and spread the seeds into the woods. Although many people find English ivy attractive, it is very invasive and can choke out native trees and shrubs if it escapes your garden. Not only will you be helping native plants by pruning your ivy, you can also use the foliage to create wonderful holiday decorations.

Give your houseplants a healthy winter treat–give them a shower! Rinsing the leaves thoroughly with tepid water gets rid of accumulated dust that blocks out the weak winter sunlight. It also washes away any mites or other pests that may be using your plant as a home.

Prune your boxwood to prevent the development of Volutella, a fungal disease that causes stem dieback. Remove any branches that are dead or discolored, then cut some of the other small branches back to the main stem. When you’re finished, you should be able to see part of the inner branch structure. This thinning will improve air circulation and sun penetration which helps prevent fungal infection. The trimmings also make a nice addition to your holiday decorations.

If you’re considering a living Christmas tree this year, be sure to plan ahead. Although they may only be six to seven feet high in your home, trees like white pine and Colorado blue spruce can grow to be anywhere from forty to a hundred feet tall. Dig your hole ahead of time so you don’t have to try to dig when the ground is frozen or covered in snow. Make it large enough to accommodate the tree’s root ball and be sure that it’s at least twenty feet away from any other plantings and structures, including telephone and electric wires. Try not to keep your tree inside for more than a week and be sure to keep it cool. Place it near a window and away from any heat sources if possible. Keep the root ball slightly moist and mist the foliage often.

It takes your houseplants a little while to adjust to being inside. Don’t worry if the foliage becomes lighter in color or some of the leaves drop. Your plants are just trying to get used to less light and lower humidity. Avoid fertilizing and water less frequently during this adjustment period.

It’s never too early to start planning next year’s garden. Take a walk around and note which plants did well during this summer’s drought and which ones suffered. A landscape is a constantly evolving thing and you shouldn’t be afraid to pull up something that didn’t do well and fill the space with a drought and pest resistant replacement. If plants that you value look dead, wait until spring to remove them. It is especially hard to tell if deciduous trees and shrubs are dead; failure to leaf out next spring is the only true test.

Now is a good time to plant new trees and shrubs. If the plant comes out of a pot be sure to break up the roots and remove any that are circling the root ball, since they will girdle the trunk as the plant matures. Remove any wrappings and twine from balled and burlapped trees. If the rootball cracks or threatens to fall apart, cut away as much of the burlap and rope as you can after the tree is in the hole. Be careful not to plant too deeply. Scrape away the top dirt and plant so that the flare of roots is just visible at the soil line. If your soil drains poorly plant a couple of inches higher to compensate. Apply two to three inches of mulch and remember to keep the mulch at least six inches away from the trunk of the tree. Mulching too close to the trunk encourages the growth of decay organisms and rodents that damage the tree’s protective bark. Be sure to keep the ground around your new planting moist, watering once a week if rainfall is scarce until the ground freezes.

Once all the leaves have fallen it’s time to prune your deciduous and evergreen trees. Remove any suckers and thin out the canopy. This will help improve air circulation and sunlight penetration to lower branches. Take out all diseased and dead branches. Check the tree’s form and remove any branches that are rubbing on others. Lower branches that are failing because of lack of light should also be removed.

Large groups of Asian ladybird beetles are beginning to congregate on the sides of houses, garages, and sheds. They especially like white houses and warm, sunny days. Their appearance varies from pale yellowish-brown to bright orange-red and they may have no spots or up to twenty spots. Like other ladybird beetles these are beneficial and you should avoid destroying them even though hundreds or thousands may congregate. Be sure to caulk your doors and windows and screen attic and exhaust vents. If they can’t find a way in they will move on. If they do make it inside put a new bag in your vacuum and suck them up. Store the bag in your unheated garage or shed until mid-April, then release them into your yard. They will appreciate the winter shelter and you will appreciate their spring appetite as they feed on your garden pests.

Now is the time to check your lilacs for lilac borers. Look for dead branches and small holes near the base of the stems or in the branch crotches. Cut off any dead or infested branches. If necessary you can cut the entire plant down to the ground. Next season it will produce vigorous new growth and the lilac borers will be eliminated since they only attack mature branches one inch or more in diameter.