Battle slugs on their home turf

Eeeeeuuuwwwww! We’ve all done it. Picked up a pot or board off the damp ground and put a hand on the bottom only to touch something really slimy. Yep, you’ve found a slug.

Our recent rains are bringing out a bumper crop of the pests to ravage our gardens. It’s time to go on the offense before they go after our hostas, delphiniums, ligularias, lettuce, tomatoes and strawberries to name only a few of their favorites. Their 27,000 (and as much as 57,000 by some estimates) little rasping teeth can shred a plant or a whole row of seedlings in one night’s feeding. They can literally eat twice their weight a night.

Slugs are mollusks and are cousins to the clam, oyster, snail, squid and octopus. Contrary to popular thinking, the slug does have a shell of sorts under its mantle. In our climate, they can grow to be upwards of six inches long over their lifespan of an equal number of years. They can be gray, black, yellow or brown in color.

An adult has both male and female reproductive systems and can produce about 100 white jelly, BB-sized eggs a year. The eggs lie dormant in the soil until the right conditions develop. Slugs are active from early spring until the fall frosts.

They locate food sources by smell and then glide to it by secreting a form of mucus from their “foot.” The mucus allows them to glide over rough and dry surfaces leaving the tell-tale shiny ribbon of slime as a sign of their presence. According to Sarah Ford in her book “50 Ways to Kill a Slug” (Hamlyn, 2003), they can actually move at about .007 mph or about 37 feet per hour.

Slugs are actually an important part of garden ecology. They are found anywhere there is a quantity of living and dead plant material. They feed on the plant material, further breaking it down and returning the organic material to the soil. They are in turn food for ground beetles, birds, ducks and other foraging animals.

That said, they get into trouble when their food sources include our prized garden plants. So what’s a gardener to do?

First, think like a slug. Slugs prefer a moist humid environment. They feed at night to avoid the heat of the day that can dry them out. During the day they hide in soil cervices, earthworm holes, thick mulches or under rocks and pieces of wood.

Remove places and things they can use to hide in or under and cultivate the soil around favored plants to disturb eggs. Trim up low-hanging branches and leaves to increase air circulation and allow drying sunlight to reach the ground. Stake up vegetable plants to keep fruit up off the ground.

Next, take the battle to their turf. Take a flashlight and a can of soapy water into the garden at night and pick the slugs off the plants and drop them into the water. Chopsticks work well as picking tools.

Trap the pests by putting out flat pieces of wood, rocks or anything flat that the slugs might hide under during the day. In the morning, pick the slugs off the bottom of the material and drop them in the soapy water.

Slugs are quite fond of melon and grapefruit so after you have your morning fruit, treat the slugs to the inverted rinds. Pick them up the next morning and knock the slugs into the water.

Set out shallow containers filled with beer, potato slices, lettuce leaves or yeast. Cottage cheese cartons buried a third of their height in the ground with slots cut to ground level work well for this. After filling them, put the lid back on to keep animals and pets out of the container. Place the containers every few feet in problem areas. There is a raging debate among some gardeners as to what kind of beer works best. Regardless, it’s the yeast in the beer that is drawing them in. Empty the trap daily and change the beer every few days.

Copper tape can be used around some plants or containers to prevent slugs from moving in. The copper reacts with the slug mucus and gives the animal a small jolt of electricity when they come into contact with it. The tape is available at most garden supply centers. The band should be about three inches wide.

As a last resort, use commercially prepared baits containing iron phosphate as the active ingredient. Iron phosphate is a naturally occurring compound and has demonstrated good control without danger to other wildlife pets or humans. It disrupts the slug’s ability to feed and they die in about a week. Some of the trade names include Sluggo, Escar-Go and Schultz Slug and Snail Bait.

Do not use table salt to kill slugs. The salt will do the job but it then gets into the soil and can be quite detrimental to plants.