13 Ways to Get Rid of Slugs in the Garden
What’s slimy, has a voracious appetite and reproduces like mad? Slugs! Learn what you need to know to get rid of these eating machines.
Slugs are the stuff of a gardener's nightmare. Slippery, slimy and squishy, these soft-bodied pests munch their way through plantings, sometimes leaving behind holey leaves, other times wiping out entire beds of seedlings.
Because they tend to feed at night, it can be tough to diagnose whether slugs in the garden are the culprit responsible for plant damage. The biggest clues are shiny mucus trails they leave behind. Slugs actually follow their trails to help find their way back home, which means you can trace the trails at times to find a slug's hideout.
Slug damage to leaves consists of irregular holes with smooth edges. They prefer to feast on soft plant material — new growth, young transplants, fruit like tomatoes or strawberries, or tender, luscious leaves like you find on basil or leaf lettuce. Slugs are notorious for the way they turn hosta leaves into lace.
You can't afford to ignore slugs in the garden because they reproduce at crazy rates. It takes about two years for a snail to mature, but once it does, it can lay up to 80 eggs at one time — and it can lay eggs up to six times a year. In other words, slugs will never just go away on their own. They'll simply multiply and wipe out even more of your plants.
The good news is that you can control these slimy critters with easy techniques. For best success, don't rely on just one method, but try a few different ways to get rid of slugs in the garden. These techniques work on all kinds of slugs (giant slugs, black slugs, gray garden slugs, etc.) and snails.
1. Give Them Shelter
Slugs lead a simple life, feeding at night and resting in the shade during the day. Exploit their need for sun protection by creating simple slug shelters in the garden. Place some boards or burlap bags in areas where they've been feeding. Lay these items out at dusk so that when the sun rises, slugs can tuck into the shelters for their daytime snooze. You can even prop up one edge of the board to make it easy for slugs to crawl beneath it. At some point before dusk, head to the garden and check your slug shelters. Scrape the offenders from the shelter's underside into a container of soapy water or weak ammonia solution.
Safety tip: When dealing with slugs and snails, wear gloves. Some species carry pathogens and parasites harmful to humans. Also, slugs and snails (and also earthworms and grubs) can carry roundworm and gape parasites, both of which can harm chickens. Avoid giving chickens large numbers of these pests.
2. Grab a Flashlight
As soon as it's fully dark outside, head to your garden with a flashlight or headlamp and a bucket of soapy water. Wear gloves and hand pick any slugs you see feeding on plants. Look for slugs on leaves, stems and fruits. They'll even climb stakes to get at ripe tomatoes, so look up and down as you search.
3. Fill a Spray Bottle
For a hands-off approach, spray slugs and snails with a vinegar solution (1 cup water to 1/2 cup vinegar). The spray literally melts the pests before your eyes. Gardeners who use this method believe that the dead slug bodies help deter other slugs from moving into the area. As long as you're not spraying zillions of slugs every night, the solution shouldn't affect plantings.
4. Welcome Predators
Like any pest, slugs have natural enemies. Toads, turtles and garter snakes enjoy a tasty slug snack, as do possums, hedgehogs and raccoons. Many birds feed on slugs, including domesticated and wild birds, like starlings, blackbirds and killdeer. Insects such as ground beetles and roving beetles also eat slugs.
The trick to hosting slug predators in your garden is to learn what they need to thrive. Ground beetles, for instance, prefer long grass, while toads like nothing better than a shady, moist patch of mulch (or the peat-based potting mix found in a tomato seedling pot, above). Don't rely solely on natural predators to control a slug population, but embrace these enemies as part of your overall slug control plan.
5. Distract Them
Many gardeners swear by putting citrus in the garden to help lure slugs from desirable plants. Simply place citrus halves — uneaten, eaten or squeezed for juice — in a shady spot near plants slugs like. Usually slugs will migrate to investigate the citrus, which they can smell. (Slugs navigate, in part, by their sense of smell.) Leave citrus halves with the cup facing up or down; either way works. Check the citrus halves frequently throughout the day and dispose of any slugs you catch.
6. Zap 'Em
When a snail or slug crawls across copper, a biochemical reaction occurs that basically shocks the pest (their slime acts as a conductor). Garden companies sell copper strips and tape, both of which last for years. For best results, keep copper shiny. If it starts to tarnish, wipe it with a vinegar solution. When using copper strips in a container, make sure your soil is slug-free to start or you may just be trapping the pests inside the copper corral.
7. Grow Resistant Crops
Outsmart slugs by landscaping with plants they dislike — ones with thick, tough, prickly or scented leaves. Lavender, rosemary, wormwood, catmint and sage fit the bill. Slugs also tend to avoid ferns, Japanese anemone, hydrangea, lantana, columbine and euphorbia. Search online for lists of slug-resistant hostas, which include these varieties: 'Rhino Hide,' 'Frances Williams,' 'Blue Mammoth' and 'Blue Mouse Ears.'
8. Change the Scene
Remove the welcome mat for slugs by eliminating their habitat — anything that gives them a place to hide during the day. This includes weedy areas, leafy branches that grow close to the ground, stones, fallen leaves and dense ground covers. Some mulches, like shredded leaves and straw, provide great hideouts for slugs. For shelters you can't remove, like the lowest rail on a fence or a deck, make it a point to trap slugs in those areas regularly.
9. Use Baits
Iron phosphate is a slug bait that acts as a stomach poison in slugs. After they ingest it, they stop eating. Look for it sold under trade names including Sluggo and Slug Magic. Sometimes it might be labeled as ferric phosphate. Iron phosphate baits are safe for use around children, birds and other wildlife.
To use, sprinkle bait on soil in areas where slugs are feeding. Apply in early evening, lightly watering after applying. A good time of year to use bait is in early spring, especially when there's little plant material available for slugs to eat (except your newly planted cabbage seedlings, above). Fall is also a good time to use baits because the garden is less full and you can more easily target where slugs are hanging out. Autumn also gives you a chance to try to reduce slug populations that overwinter. Iron phosphate is an OMRI listed pest control method, which means it's safe for use in edible organic gardens.
10. Water Wisely
Where you can, use drip irrigation to limit the amount of water that pools on plant leaves and soil. Slugs crave moisture and humidity, and not using overhead sprinklers helps reduce the amount of water on surfaces. Try to water close to sunrise so surfaces have all day to dry out before dusk and slug feeding time arrives.
11. Try Liquid Traps
Beer traps are the classic method for eliminating slugs. You can buy these traps or make your own. Bury a deep container with a lid, like a coffee can or cottage cheese container, so it's level with surrounding soil. Make a slug-size hole in the lid, add an inch or two of beer and snap the lid in place. Slugs smell the yeasty aroma and crawl into the trap and drown. These types of traps lure slugs within just a few feet of where they're placed. You don't have to use beer — a mix of sugar, water and yeast works, too. Empty traps regularly and replace the solution every few days. Some gardeners say the traps don't have to be buried to work. Experiment and see what works best in your garden.
12. Create a Barrier
Surround vulnerable plants with a barrier that harms slugs: diatomaceous earth (DE). The diatoms (fossilized phytoplankton) that make up DE shred soft slug bodies, which causes them to dry out and die. Apply DE in a band 1 inch high and 3 inches wide. Replace DE after it becomes damp. Many sources suggest using crushed eggshells or coffee grounds to create a slug-resistant barrier around plants, but studies have shown that these don't work.
13. Harness the Sun
Use solarization to kill slug eggs in planting beds. With this technique, you cover the soil with a clear tarp and let the sun's energy heat up soil. Another way to kill slug eggs is to expose them to air by turning soil over with a hoe or shovel.