They strike in the shadows of darkness – munching on seedlings and chewing irregular holes in foliage – and leave little evidence besides the unsightly damage. Observant garden detectives may detect faint silvery trails of slime left behind during their getaway.
Who are these garden ne’er-do-wells? Slugs.
Most common garden slugs are small – 1/8 to an inch or so long – but they can do an alarming amount of damage in just one night. They cut through foliage with their chainsaw-like mouthparts.
Slugs move across the garden on slime they secrete through their feet. They love cool, moist, shady spots, and their favorite cuisine is the new tender growth of seedlings, leafy vegetables like lettuce, cabbage and salad greens, and hostas.
During the day slugs take cover beneath mulch, leaves, dense ground covers, logs, boards and anything else that shelters them from the sun. This is also where they lay clusters of eggs.
Gardeners, normally nurturing types, turn into revenge-seeking fanatics when slugs prey on their preferred plants. They are willing to try just about anything to rid their garden of the slimy beasts from altering gardening practices and homemade concoctions to toxic chemicals.
If you are in a battle with garden slugs, here are several methods of control you can try. None of them are fail safe but, with some experimentation, you may find a product or practice (or combination of methods) that work for you.
Cultural practices can dissuade slugs.
Reduce the number of slugs by eliminating their hiding places during the day. Remove mulch and clean up garden debris. If you are emotionally attached to mulching, use shredded bark or pine straw. Slugs don’t want to travel across rough terrain.
Invite frogs and toads to take up residence in your landscape. These natural predators enjoy slugs for dinner and their eggs for dessert. Turtles and snakes also enjoy a slug snack. Gardeners who raise chickens or ducks rarely have problems with slugs.
Lure slugs into your trap.
Slugs are drawn to the scent of stale beer. If beer doesn’t last long enough in your house to get stale, boil some yeast and honey in water. Fill a container with either beer or the yeast/honey mixture and bury it so the top of the dish is even with the soil. Slugs, believing they are about to belly up to the bar, get a deadly surprise when they slip in and drown. Get rid of the bodies every morning and refill the container as needed.
Moisten a piece of cardboard (or several layers of newspaper) and set it in the garden where slug damage is apparent. In the morning, flip it over. If slugs are present, throw it away in a sealed plastic bag. Worried about landfills filling up with your slug traps? Drown slugs in soapy water and reuse the cardboard.
Some gardeners report success using dry dog or cat food to ensnare slugs. If I tried this in my yard, raccoons and possums would come from all over the neighborhood to join the slug party.
Send slugs packing.
Slugs do not like copper. It reacts with the mucus on their bodies, feeling like a small electrical shock. Copper barriers work best on the edges of raised beds or containers. Be sure the strip of copper is wide enough so slugs can’t raise up and get over without making contact.
Diatomaceous earth is a powdery substance made up of the fossilized remains of hard-shelled algae. When a slug moves over diatomaceous earth, the underside of its body is cut causing dehydration and eventual death. Diatomaceous earth is only effective when it is dry and must be reapplied on the ground after every rain.
Anything scratchy is despised by slugs. Sandpaper cut into strips, wood ashes and crushed eggshells can all play a part in slug control.
Cook up something special for slug control.
Some gardeners make a homemade brew of one part ammonia to four parts water. Others have tried a concoction of equal parts vinegar and water. Both must be sprayed directly on the slug. I have not tried either of these and would caution spraying plants with either one.
Kill ‘em with your bare hands.
Not everyone can do this, but if enough prized plants get damaged, even the most squeamish gardeners get angry enough to smoosh them, stomp them or drown them.
Hand picking slugs can be done by day if you lay boards on the soil for them to gather out of the sun. Or go on assault at night with a flashlight (or a fashionable head lamp) and catch them in the act. Either way smoosh them, stomp them or drown them.
Use chemicals for slug control.
Iron phosphate is the active ingredient in many products you can purchase for slug control – Sluggo, Slug Magic, and Escar-Go are just a few. Besides iron phosphate, the pellets contain a bait to attract slugs. Sprinkle them on top of moist soil. After slugs eat the pellets, they stop eating and die within a few days.
Products with iron phosphate remain effective even after several rains. They are safe to use around children, pets, birds, beneficial insects and other wildlife. They can also be applied around vegetable plants right up to the day of harvest.
There are other chemical options, but I would not recommend them because of their toxicity.
The best plan to control slugs in your landscape is to start early in the season and keep after them. Grab your flashlight and go slug hunting. Then get ready to garden with me!