Summary: Slugs are common pests during wet weather and can damage many types of plants in the garden. The slug feeds mainly at night, preferring cool, moist hiding places during the day. Cool, wet spring conditions will result in large slug populations.
A reader asks: Slugs travel across my very large back yard lawn and make their way each night to the back porch. By 8 PM there are at least 5-10 slugs at my back door. There is no food source there. I just wonder why the journey there and how can I stop it?
Dear Reader: The slugs you are finding at your back door are seeking the moisture that gets trapped along the foundations of most structures. The east and north sides of structures usually provide the most shade and that is where most slugs will be found.
Slugs are common pests during wet weather and can damage many types of plants in the garden. They feed mainly at night, preferring cool, moist hiding places during the day. Cool, wet spring conditions will result in large slug populations.
To keep slug populations in check you'll need to keep the area free of accumulations of leaves, prunings, piles of old boards, stones or anything that can provide a cool, moist hiding place for slugs. Keep the ground as dry as ***image1***possible. Use drip irrigation, soaker lines or other techniques to limit water and decrease the humidity around plants. Use of lawn sprinklers should be done early in the day to allow more time for leaves and soil to dry before the nightly activity of slugs.
Slugs are not susceptible to poisoning by most insecticides, but there are several products that claim to control slugs. Use these products with extreme care. These products usually contain methaldehyde and are sold under the names of Bio Slug Mini-Pellets, Slugoids, Deadline, Slug-it and many more. Read the label carefully and do not allow the material to come in contact with leaves of vegetables.
A safer method of slug control would be via the use of beer traps. Pans of beer or a sugar water and yeast mixture will attract, trap and drown slugs. The slugs love the smell of fermentation and they fall in the can and become trapped. You'll need to freshen the traps every few days to remain effective and you'll need to place enough traps so the slugs can easily find the traps.
Diatomaceous earth, lime or sawdust can be used around bedded plants in wide bands. The band serves as a repellent because the materials dry out the slug and they won't cross over it. The downside is that these barriers need to be replaced after each rain.
Ammonia sprays make excellent contact treatment, but must be applied directly to exposed slugs. Household ammonia, diluted to a 5 percent to 10 percent concentration, is effective for this purpose.
In addition to this information, please see an article written by Dr. Bill Symondson, Cardiff School of Biosciences, Cardiff, UK. He really gets into all the details of every type of control method you can imagine. Click here to see Dr. Symondson's article.