Volume 13, Issue 31 ~ August 4 - 10, 2005

Dr. Gouin's Bay Gardener

Once these bandits have had a taste, there’s little to deter them

Raccoons know exactly when your sweet corn is ready to harvest. Matter of fact, they will invade your garden before you can even detect that the corn is ready to pick — and there are no fences that can keep raccoons out. I have not as yet seen a commercial product capable of repelling raccoons.

However, raccoons are very suspicious of flashing lights at night. A single 60-watt bulb mounted over a flasher inserted in the light bulb outlet and surrounded with a cone of aluminum flashing, to reflect the light toward to corn patch, will deter raccoons from entering the garden. Using pop-rivets, 14-inch-wide aluminum flashing can easily be fashioned into an effective reflector. While the corn is in its final stages of ripening, the flashing light can be activated by a 24-hour timer to go on after sunset and to turn off just before sunrise. If the corn planting is larger than 30 feet in depth or if you have multiple plantings, you may be required to install two or more such flashing lights. I have my lights mounted on six-foot-tall, three-quarter-inch pipe so I can move them from place to place as each planting of corn matures.

Don’t wait to install the flashing lights until after the raccoons have attacked the corn. Once they have had a taste, the flashing light is less effective in deterring them. Soon after the silk on the ears has turned brown, check a few ears of corn for maturity. Activate the light as soon as the kernels at the tip of the ears start to fill in.
Plagued by Bagworms

Q Great article on bagworms in Bay Weekly [Vol. xiii, No. 28: July 14]. I’m surrounded by bagworms every year. So far they have not won; my trees are still standing but show the infestation. I have questions I’ve wondered about for a very long time and I am at a loss for what to do.

  • Why are they on my trees and not my neighbor’s? My neighbor has a lawn service. Does this prevent them?
  • Is there a preventative to use before they appear?
  • If spraying has a time limit and I should pick off the large bagworms, what do I use or do with the bagworms 20 feet up?
  • Does soapy water spray really work?
  • Is there a book or detailed article I can read about bagworms?

—C. Knicley

A Bagworms tend to prefer some trees over others. We do not know why. I have 2,500 Christmas trees growing on my farm, but only a couple of dozen trees are infested with bagworms. Those are the only trees that I have to spray.

If your neighbor’s lawn service is applying systemic insecticides to control lawn insects, it could be that the tree roots are absorbing some, but without information on what is being applied, I cannot give you a complete answer.

Insecticidal soaps do not kill bagworms.

You will find it impossible to control bagworms on a 20-foot-tall tree without using a hydraulic sprayer. By now, BT will no longer control them because they are too large. You will need to use Sevin.

There are lots of articles on bagworm control as it is a very common pest. Visit a garden center where there is an information corner or book rack.

Professor Emeritus Francis Gouin retired from the University of Maryland, where he was the state’s extension specialist in ornamental horticulture. Follow his column of practical gardening and plant advice every week, only in Bay Weekly. Ask Dr. Gouin your questions at [email protected].

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