Articles in this newsletter written by Martha Smith, David Robson and Elizabeth Wahle

Act Now to Control Tent Caterpillars

Remember the caterpillars that made silk tents in the twig crotches and ate the leaves of your crabapple tree last spring? This insect, the eastern tent caterpillar, has hatched and may be feeding on your trees. The eastern tent caterpillar prefers wild cherry, apple, and crabapple, although it also feeds on ash, birch, willow, maple, oak, poplar, cherry, plum, and several other tree species.

This is one of the first insects to hatch in the spring, closely following bud break on the host tree. The young caterpillars gather at a branch fork or crotch and spin a white silk tent about 1 inch in diameter. The caterpillars stay inside of this tent at night and during rainy weather.

During the day, the caterpillars crawl out onto the branches, spinning out a single strand of silk as they move away from the tent. Before nightfall, after feeding on the leaves during the day, they retrace their steps along the silk strand back to their nest.

As the caterpillars grow, they enlarge their silken tent. They develop a white stripe down the back with a row of blue spots bordered with longitudinal yellow lines on either side of the stripe. Around the end of May, these caterpillars separate and each one spins a white silken cocoon on the tree trunk or some other object. The adult moths emerge in June.

After mating, the females lay their eggs on twigs that are usually about the diameter of a pencil. The egg mass is dark brown and usually extends completely around the twig. Each egg mass is about ¾ inch and contains 150 to 350 eggs. These eggs do not hatch until the following spring.

Control of the eastern tent caterpillar can be accomplished by several methods. On small trees, such as crabapple, the silken tents can be removed at night when the caterpillars are inside. The caterpillars can then be squashed or dropped into the trash. The trees can be sprayed with the organic insecticide Bacillus thuringiensis (Dipel, Thuricide) to kill the larvae as they feed on the leaves. For other chemical options, contact the local U of I Extension office for up-to-date recommendations.

Spring into Lawn Care

Spring isn't the best time to improve the lawn, but it's a close second. Fall is the ideal time to renovate or improve lawns due to a longer period of cool temperatures. However, spring temperatures may be more ideal for sowing grass seed and controlling annual weeds.

Most lawns in southern Illinois are composed of cool-season grasses. These grasses include Kentucky bluegrass, perennial ryegrass, and fescues. Temperatures in the range of 50 to 80 degrees are ideal for root growth and shoot development of plants. Temperatures on the cool side tend to encourage more root development while warmer temperatures favor shoot growth.

Spring lawn care should be looked at as a means of ensuring a good stand of grass capable of surviving summer's temperatures and moisture conditions. Roots are the most crucial elements to survival. While summer heat and drought may kill shoots, an unaffected root system should have the ability to generate new plants in the fall. All spring lawn care activity should be aimed at increasing the plant's root system and shoot density. However, many traditional spring practices do the opposite.

Fertilizing in April is considered normal, but it is actually one of the worst things to do. Fertilizing stimulates top growth at the expense of root growth. The lawn will develop an attractive color and thicken, but the root system will lag behind. As long as temperatures remain on the cool side, no noticeable effect is viewed. But, when temperatures warm, the root system struggles to provide adequate moisture to keep blades and crowns alive.

In southern Illinois, it's generally agreed to forego spring fertilizing until mid-May. Around Mother's Day, supply the lawn with 1 pound of actual nitrogen per 1000 square feet to increase shoot growth for the summer. It may take time to adjust to the concept of late spring fertilizing especially when the neighbor's lawn may appear greener and thicker. But like all landscape care, the long-term results are better than the short-term ones.

The first week of April is the time to apply crabgrass control. Crabgrass is a warm-season annual weed with a leaf blade three to four times as thick as bluegrass. The difference in appearancecontributes to crabgrass's weedy nature. Crabgrass germinates when temperatures are above 55 degrees for 5 to 7 consecutive days. Pre-emergence herbicides provide the best weed control. Follow directions on the package and water in because pre-emergence chemicals have little effect if they are not near the weed seed as it germinates. Avoid using pre-emergence controls if overseeding is necessary. Most chemicals are unable to distinguish between weed seed and grass seed. While pre-emergence weed control and fertilizer combinations are available, it's still best to wait until May before fertilizing.

Other spring practices to consider include de-thatching, aerating and overseeding. Finally, start mowing the lawn as soon as it needs it. Before you start up the mower, be sure to pick up debris such as sticks and twigs.

Spring Lawn Care Guide

When the lawn care questions start coming in, be sure to refer clients to the Spring Lawn Care Guide. You can get copies at the local Extension office or download the fact sheet from the Southern Illinois Lawn and Garden website:http://web.extension.uiuc.edu/regions/lawnandgarden/hort.html

Handpick Bugs Now to Reduce Bagworm Problems

Bagworms, which are really moth larvae or caterpillars, feed on the foliage of many trees and shrubs in our area. The individual caterpillars are not as noticeable as the dangling, 1- to 3-inch long bags they create from bits of dead foliage and twigs interwoven with silk. In the summer, they drag these silken bags along as they feed. When feeding, bagworms usually start from the top and work their way down a branch. When all the leaves are eaten off the branch, they move to the next one.

By late August, the larva attaches its bag to a twig and pupates. In a few days, the winged male moths emerge in search of bags containing wingless females; they mate, and the male moth dies. After laying up to 1000 eggs, the female dies. The eggs then spend the winter months in the mother's bag. In the spring (late May to early June), the small brown caterpillars hatch and disperse to feed. They are blown from tree to tree on thin threads, spreading and starting the cycle all over again.

A heavy attack by bagworms may stunt deciduous trees or kill evergreens. Taking time now to handpick the bags off your valuable landscape trees and shrubs is a worthwhile and environmentally friendly way of reducing bagworm damage come May. The more thorough you are now, the better control you will have this summer. Once removed, the bags should be burned to assure the caterpillars inside will not hatch out elsewhere in your yard or garden.

Trees and shrubs infested with bagworms may be sprayed with an insecticide containing acephate, Bt, or carbaryl. Spray applications will only be effective when applied sometime from late May to mid-July when the young caterpillars have hatched and begun to feed. You must re-spray after seven to 10 days if leaf damage is still occurring. Bt, Bacillus thuringiensis, is a bacteriumthat is effective against several caterpillar pests when they are young. After eating Bt treated leaves, caterpillars die within two to three days. Spraying plants with Bt, a biological control, is the preferred control when handpicking is not an option. As with acephate and carbaryl, Bt is sold under many trade names that can be found at most local nurseries and garden centers. If you choose to spray for bagworms, be sure you read and follow all label directions.

Using Ash in the Garden

Often, clients ask whether they can use ash from their fireplace or wood stove in the garden. As with many gardening practices there are pros and cons for using ash in the garden.

Applying small amounts of wood ash to most soils will not adversely affect garden crops, and the ash does help replenish some nutrients. But because wood ash increases soil pH, adding large amounts can do more harm than good. It is not recommended to use ash around acid-loving plants.

Encourage clients to find out what the soil pH in their garden is before adding ash.

Notes from Sharon

As I write this Wednesday afternoon, the sun is shining and March is coming in like a LAMB. So you know how that saying goes and what could happen by the end of the month. Of course, it could change by the end of the day too–this is Illinois.

The Master Gardener training is proceeding in Effingham. There will be one change in the schedule. Graduation and Tour Day are being reversed. This will allow the County Directors (used to be called Unit Leaders) in the area to participate in the graduation event. The spring County Directors meeting for the state is scheduled in Quincy on the original graduation date. We do hope to get the Coles County mentors and trainees matched up by the end of March.

Ann and her committee have been busy filling sunflower seed bags and planning the annual display for the Mall Show this weekend. U of I Extension is having a manned display this year---maybe we will be close together. I'm working the Saturday evening shift, so hopefully will get to see some of you then.

I'm assuming those of you who have grow lights or greenhouses, are already playing in the dirt, excuse me 'soil.' Herb Fest will be here before you know it. Try to remember what interested customers last year and make sure MGs are able to provide those plants again this year.

There is a teleconference coming up next week that some of you may be interested in attending for education hours. Dave Shiley, U of I Extension Natural Resources Educator will discuss 'Wildlife Nuisance Control' on March 14. The teleconference will be held from 6:00 – 7:30 pm at the Extension office. The teleconference fee is $3 and registration is limited to 12 participants. The deadline is Friday, March 10. I'll have a few flyers available at the meeting.

The Advisory Board of Master Gardeners (all committee chairs and the officers) will meet at the office on Tuesday March 21 for the semi-annual meeting. Please reserve 3 – 4:30 on your schedules.

Spring officially arrives this month! YEA!

Sharon