Protect your plants from spring insects

Hopefully, this past week's cold weather will be the last that we have until fall. I know many gardeners who had to cover their plants a couple of nights to protect them.

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However, the frost and cold weather didn't take care of the insects that are attacking our plants. These past few weeks, I received many calls on insects that are showing up on our plants.

This time of the year, we are in a transition time in the garden. We have winter vegetables finishing up their growing season, and at the same time our summer vegetables are starting. So we can have insects that move from one vegetable as it matures to another young plant and continue the cycle.

There are many insects that can be active in the winter and summer gardens.

I have received more calls about cutworms this year than I have in many years. Cutworms are caterpillars that live buried in the soil during the day and come out at night to feed.

They get their name from the damage that they do. They wrap themselves around a small plant and cut it off about half an inch above the soil.

There are several ways to protect your plants from cutworms. The first is to use a barrier to keep them from encircling the stem of the plant. You can do this by putting a piece of aluminum foil around the stem of the plant. The aluminum foil needs to be wrapped loosely around the stem so that one inch is below ground and two inches above. When the stem of the plant reaches one-half inch or greater in diameter, you can remove the foil. Also, you can place twigs or toothpicks around the stem of the plant to keep the cutworm off the plant.

You can use insecticides to control cutworms as well. Some of the better products to use are bifenthrin, cyfluthrin and Sevin. You can apply these products to the stem of the plant, and repeat as needed.

Another pest in the garden is the fire ant. Most of the fire ant products used in lawns and shrubs are not labeled for use in the vegetable garden, so we have to look at other ways of controlling them.

If they have mounds present in the garden, you can use products such as bifenthrin, malathion and cyfluthrin as mound drenches to control them. However, read the label to make sure that the vegetable near the mound is on the label of the insecticide. To drench the mound, start pouring the insecticide two to three inches around the outside of the mound. Then pour over the mound. This will cut off the escape route of the fire ants.

For an organic control, try club soda. This treatment was brought to my attention last fall, and a few of our master gardeners tried it and said it worked. Apply two cups of club soda to an averaged-sized mound. The way that this works is the carbon dioxide in the club soda is heavier than air and replaces the oxygen in the mound -- so the ants suffocate.

If you are seeing fire ants on your plants, this is an indication that you have aphids. Aphids produce a sweet, sticky substance called honeydew. The ants use this as a food source. The ants are not harming the plants, but the aphids are. One of the best ways to control aphids is to let beneficial insects populations build up to take care of the problem. Ladybugs are one of the best insects at controlling aphids.

Another option is to use insecticidal soaps. Insecticidal soaps work well on soft-bodied insects, but don't harm beneficial insects. You can use insecticides to control aphids. Some of the more commonly used insecticides are malathion and bifenthrin. If you use insecticides, use them late in the day. This will help protect the bees.

One of the biggest problems on tomatoes is the tomato hornworm. This is large caterpillar that will eat all the foliage on a tomato plant. One of the best ways to control them is pick them off. You also can plant basil around your tomato plants, and the basil will repel the moth that produces the hornworm.

Columbia County Extension Agent Charles Phillips can be reached at (706) 868-3413 or by e-mail at charlesp@uga.edu. The Extension Web address is www.ugaextension.com/columbia.