Master Gardener: Examining insects, weeds and other garden problems | Lifestyles

It’s been a busy couple of weeks on the Master Gardener Helpline.

Now that we are in the garden regularly and things are starting to grow, we are also finding insect, weed and disease issues. The Master Gardeners can help identify what’s bugging you and come up with a solution following Integrated Pest Management best practices.

n Sticky bedstraw (Galium aparine) has been the star of the garden when it comes to weeds. It seems to be appearing everywhere this year, even in beds where it was not last year.

Sticky bedstraw is a winter or spring herbaceous annual. It can germinate late summer into fall and puts on several inches of growth before winter.

Come spring it is ready to leap into weedy action, quickly outgrowing surrounding plants. It can easily grow 3 feet long or more and engulf a plant with its sticky stems and leaves.

Bedstraw often forms dense, tangled mats that spray on the ground or over neighboring plants.

Be on the lookout and pull this weed the minute you see it. It is getting ready to distribute its crop of seeds for next year.

You may be able to take a rake and carefully lift it off plants, so it doesn’t damage them.

Plants start to wither once the seed has set but they are still a sticky nuisance. If mature bedstraw is composted the seeds will survive, so once it has flowered dispose of plants in the garbage.

n We’ve had several questions come in about plants that have small, circular discolored areas on the leaves, or leaves with curled edges that look crispy. If you have strawberry plants, you might find that your fruit is misshapen.

These are all signs of two common insects — Tarnished Plant Bug (Lygus lineolaris) and the Four-Lined Plant Bug (Poecilocapsus lineatus).

Both are members of the Hemiptera order of insects and feed on a wide variety of plants. They feed by inserting their piercing-sucking mouthparts into plant tissue and sucking out the sap.

It is thought that they also inject a toxic substance — possibly digestive enzymes — into the plant when feeding which breaks down plant tissues.

Tarnished plant bug adults are about 1/4 inch long, oval shaped, bronze to dark brown, with white marks behind the head and sometimes along the front wing. The immature stage, or nymph, is wingless, and they are usually green, while some younger ones can be yellowish.

Older nymphs will have black spots on their backs.

Four-lined plant bug adults are a quarter to a third of an inch long. The body is a greenish yellow with four black stripes running down the wings, hence the name.

The head is orange-brown, and the legs are a yellow green.

Newly hatched nymphs are bright red with black dots on their abdomen and black wing pads. Older nymphs are more of a reddish orange with a light-colored stripe on the wing pads.

Both adults and nymphs can damage plants.

If populations are high and damage is serious, spraying with an insecticidal soap may be necessary. Identify which you have so that you can institute other IPM practices.

n When you are weeding have you found some small, white, wingless insects that appear to have a white powdery wax over them? You have likely found a colony of root aphids (Pemphigus species).

I frequently find them on dandelion taproots.

When they are on a weed, no worries. Off to the compost pile or garbage (depending on the weed) they go.

However, they can cause problems in desirable plants.

Symptoms include plants that wilt during the day; leaf yellowing; and taproots that are short, limp, and rubbery with many root hairs. You might notice, during dry periods, that a small circular patch of plants has collapsed.

In a garden setting they are usually not a big problem.

If you find them in your vegetable garden remove and destroy infested plants. It is recommended to till the soil before planting and rotate susceptible crops.

Managing root aphids with an insecticide is challenging for homeowners because the soil must be soaked. Their waxy coating can also protect them from insecticides.

n If you have crabapples, you are probably familiar with apple scab.

A common disease of apples and crabapples, infected trees are currently experiencing leaf drop.

Apple scab is caused by the fungus Venturia inaequalis. It overwinters on fallen diseased leaves and spores are released in the spring.

Infected leaves develop round, olive-green spots that can be up to half an inch across. Fruit can also become infected.

The olive-green spots turn brown and then corky over time. Fruit can also become deformed and cracked.

Fungicides can be used to protect susceptible trees, but it must be applied before the tree is infected.

Sanitation is an important part of helping to prevent this disease. Clean up fallen leaves and fruit.

Annually prune trees to open the canopy and allow for better air circulation. If you are adding a crab apple to your landscape, look for scab-resistant varieties. Trying to time sprays every year can be aggravating.

n I found this really big bee/wasp. Did I find a murder hornet?

Probably not, but send us a photo or bring it into the office for identification. In all likelihood what you found was a queen European Hornet (Vespa crabro).

The Asian giant hornet (Vespa mandarinia), first detected in the Pacific Northwest in 2019, has not been found on the East Coast. However, European hornets are well established in the area.

Queens can reach 1.3 inches and are rather intimidating. The head is red and yellow, and the thorax (middle region) is red and brown.

The abdomen has two large brown sections by the waist and a mostly yellow posterior with brown tear-drop markings.

European hornets build annual nests, usually in hollow trees or possibly a wall void. Only fertilized queens survive the winter to start a new colony the next year.

Queen hornets need a safe place to over winter and if they happen to do that in your attic, they may find their way into your house in the spring when they wake up.

The best option to keep them out is to seal cracks that can give them access to your house. Like other hornets they prey on insects such as grasshoppers, flies, and even yellowjackets.

They do have a sweet tooth in the fall and might be found around fallen fruit. They are also known for stripping bark off shrubs to get to the sap.

Remember if you have a gardening question, Master Gardener volunteers are in the CCE Genesee office Monday through Friday, 10 am to noon. You can stop in at our CCE office at 420 East Main Street, Batavia, or call (585) 343-3040, ext. 127.

You can also e-mail questions or photos to them at Helpline volunteers are happy to help you solve your garden and landscape problems.

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