CORVALLIS, Ore. – Just as we begin to think about wrapping things up in the garden for the season, slugs slither out of their homes underground to lay their eggs for next year.
“What slugs want is a place that’s warm and moist,” said Claudia Groth, an Oregon State University Extension Service master gardener. “That’s why spring and fall is when they’re most active. They’ll be coming out soon to lay eggs.”
The eggs hatch fairly rapidly and the fast-growing slugs wait it out, showing up in spring to scrape and shred plant leaves with tongues lined with thousands of tiny, extremely sharp teeth. Eggs will mature slowly over winter and hatch in spring.
“In fall, you’re trying to kill them off before they lay eggs,” she said. “In spring when your plants are poking their heads up, you need to protect them, because once the leaves are nipped, the damage is there all summer.”
Since slugs go on attack at night and look for protected places during the day, you’ll find them under ground covers or mulches and in thickly planted perennial or annual borders.
“Many gardeners grow plants tightly in their beds to keep weeds from growing,” Groth said. “That’s an environment that provides them with a 100 percent hiding place all day.”
“So, the first thing to do when starting a control program is to clean up the garden,” she said. “Don’t leave things all over the yard. They can even hide under garden gloves.”
Raise pots onto bricks or “pot feet” purchased for that purpose. Pull mulch away from favorite plants. Remove weeds where the pests like to nestle down. Tidy under porches and other raised structures.
Although sanitation is the first line of defense, there are plenty of other methods for control. Get started now. Young plants are most susceptible. Here are Groth’s recommendations:
Water in the morning. “If you water in the evening, it’s wet until early in the morning and you’ve given them the best environment when they come out at night hungry,” she said.
Put out beer traps. Use a pie plate or bury a plastic yogurt or margarine container almost to the rim. Pour in beer. Remove dead slugs daily and refill with beer.
Don’t use salt. It can build up in the soil and damage plants.
Attract predators such as frogs, ground beetles and, yes, snakes.
Create an artificial hiding place by placing a board in their favorite places. To make it especially attractive, grind up lettuce and brewer’s yeast (not baker’s yeast) and put that under the board. In the morning, lift the board and remove slugs. Drop them in a bucket of soapy water.