37April 25, 2019

I noticed that the leaves are beginning to unfurl on the maple trees in my backyard. As those leaves unfurl, we will probably be seeing one of the first pests of the season. The winter moth caterpillars will be hatching from the egg masses that were laid on the trunk of the tree last November or early in December.

This tiny green and white caterpillar loves to dine on the leaves of your maple trees. The winter moth caterpillar also likes to eat the leaves of many of the ornamental fruit trees. We had a flowering cherry that they loved to dine on each spring. The caterpillars will feed for – give or take – about 4 to 6 weeks. Yet in that 4 to 6 week period they can do a lot of damage to the leaves of your trees.

In the last few years, the winter moth caterpillar stopped feeding at just about the time that the Gypsy moth caterpillars began to hatch out and feed on trees. This one-two punch of caterpillars attacking the trees did weaken some trees. Years of repeated attacks could cause the trees to weaken to the point that the trees may die. The question is what can you do to stop the damage from these caterpillars.

Many people have used a product called Bt to control the winter moth caterpillars. Bt is a bacterium spray that is deadly to caterpillars but is not harmful to most other organisms. If the bacteria in a Bt spray infected a caterpillar and a bird came along and ate the caterpillar, the bird would not be harmed. What you need to do is to mix the BT spray with water and you would then spray that solution onto the leaves of your trees. As the caterpillar feeds on the leaves, it ingests the bacteria and soon the caterpillar stops eating and soon after that the caterpillar dies. If you can do a repeat application at about the time the gypsy moth caterpillar hatches, you can kill off many of the gypsy moth caterpillars too.

Bt can be used against all types of caterpillars including the tomato hornworm and those pesky green caterpillars that get into your broccoli and cabbage plants. Many of the hard-to-control caterpillars that destroy your petunia plants will be killed by an application or two of Bt. Generally speaking if it is a caterpillar feeding on your plants, Bt is the first control method that you should be using.

With the warming weather, I have had people asking me about planting tomato plants. Tomato plants need warm soil to grow properly. If the soil is still cold, the plants will be stunted. If they are exposed to a late frost, they will die. The old timers always said to wait until Memorial Day to plant tomato, pepper, cucumber, squash and eggplant seedlings. I will grant you that the month of May appears to be warmer earlier in the month nowadays, but I have said for years that people who plant tomato plants too early have a name: Repeat customer.

The forsythias are in bloom and that means that if you are going to be trying to control crabgrass in your lawn, now is the time to apply a pre-emergent crabgrass control to your lawn. The crabgrass plants that were in your lawn last years dropped 100’s of seeds before the plants were killed by the first frost The pre-emergent control kills the crabgrass seed before the seed can turn into new crabgrass plants.

Well, that’s all for this week. I’ll talk to you again next week.

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