Slugs like a damp, mild climate.
Slugs (and snails) like living in Oregon. Our mild, wet climate seems like paradise to them. There are a dozen important slug species in Oregon gardens (and a couple of snails—the brown garden snail and amber snail). Most of the time, slugs and snails are beneficial because they recycle organic matter and are food for wildlife.
Slugs are most active when the environment is moist. They feed at night when the temperature is above 50°F, wind is low, and humidity is high.
Slugs are common garden pests. They leave slime trails and ragged holes in leaves.
Slugs feed on many kinds of garden plants, such as annuals, perennials, flowers, fruits and vegetables. You can tell slug damage from other pest damage by the slime trails on the ground and on damaged plants. Slugs chew ragged holes with smooth edges between the veins of leaves. The presence of sausage-shaped feces in the garden are also signs of slugs and snails.
Place small boards in the garden and remove slugs every morning.
Slugs seek dark, moist places (such as under mulch and leaves) to hide in during the day. To “trap” them, place small boards or shingles under your garden plants. Every morning, remove the slugs you find under these shelters. Put the slugs in a bucket of soapy water, or feed them to chickens.
Your first chance to control slugs is in September and October, after the first rains begin and before the slugs lay eggs. The next chance to control slugs is early spring.
Slugs and snails lay eggs in the fall when the rains begin, generally at the end of September or the beginning of October. After they lay their eggs, adult slugs usually die or “hibernate.” Reduce the number of adult slugs before they lay eggs, so you will have fewer problems in the future. If there are still many slugs over the winter, control them in early spring before they begin feeding again.
Pick slugs off plants after dark.
About 2 hours after sunset or in the early morning before slugs hide under a shelter, examine your garden plants closely and often. Use a headlamp or flashlight to help see the hidden slugs. Remove the slugs, cut them up, squash them, feed them to chickens, or toss them into a pail of soapy water.
Make a beer trap.
Beer smells of yeast, and this smell attracts slugs. To make a beer trap, use an empty margarine or yogurt container. In the upper third, cut a hole 2 inches in diameter. Bury the container so that the hole remains slightly above ground. Add 2 or 3 inches of beer. Cover the top of the container to keep pets from drinking the beer! Remove the dead slugs each day and add more beer.
Work the ground to reduce moisture and destroy a slug’s hiding places.
Slugs require moisture to live, so anything you can do to get rid of moist, shady places in the garden will help. Slugs hide and lay their eggs in dark, moist places below plants, in cracks, and under plant residue. Work the soil 4 to 6 inches deep to get rid of these sites, and water the garden only in the morning. If you water late in the day, the garden stays moist overnight, and the slugs like that.
Use “trap plants” and check them regularly for slugs.
Slugs love marigolds. If you plant these flowers along the edges of your garden, they will “trap” nearby slugs by attracting them. This will make it easier for you to find and remove slugs and dispose of them.
Protect your plants with copper barriers. They give slugs an electric shock.
When a slug touches copper, it receives an electric shock and backs up. Surround raised beds or individual plants with a 3-inch-wide band of copper. Or, make a cone shape with a spiral of copper wire and wrap it around a potted plant. Stick the point of the cone in the ground and surround the plant with the spiral. Make sure there are no slugs inside these barriers!
Surround plants with a band of diatomaceous earth 1 inch deep and 3 inches wide to create a barrier.
Diatomaceous earth is made from ground fossils. This powder pierces the skin of slugs. Surround the plants with a band 1 inch deep and 3 inches wide.
This powder is not effective when it is wet. You’ll have to apply more after rain or irrigation.
Baits can also control slugs, but you must use them carefully.
There are three common types of baits that are toxic to slugs that can be used in gardens. The active ingredients are metaldehyde, iron phosphate, and sodium ferric EDTA. If you use any of these products, remember that they may also be toxic to children, pets, and wildlife. A bait’s success can be affected by weather, a slug’s age, and the level of slug activity at night. Carefully read the labels before you buy and use them.
To minimize your pet’s access to the bait, bury a milk jug or large yogurt container half-way on its side in the ground. Put a dozen pellets inside the container. Cut a 2-inch hole near the top or side of the container. Most baits contain a feeding attractant that entices slugs to enter. Slugs will die after feeding on the bait, but it may take 1 to 5 days, depending on the bait.
Use pesticides safely!
- Wear protective clothing and safety devices as recommended on the label. Bathe or shower after each use.
- Read the pesticide label—even if you’ve used the pesticide before. Follow closely the instructions on the label (and any other directions you have).
- Be cautious when you apply pesticides. Know your legal responsibility as a pesticide applicator. You may be liable for injury or damage resulting from pesticide use.