We live in an abundant universe. July is the ideal time to contemplate this fact as it relates to the garden. Outrageous displays of beautiful flowers are showing up everywhere as we enter into the peak blooming time of the summer perennial garden. On the other hand, weeds and unwanted vegetation are also growing at a fast clip, smothering buildings and gardens seemingly overnight! Ready to attack all of this lush plant material are the hidden, nightly visitors to every garden…SLUGS!
The most fertile imagination could not have dreamt up a more disgusting creature! Essentially snails without shells, slugs are slippery, slimy creatures that hide in dark, damp places, slithering out at night to munch away at your prized garden flowers. You can tell that they’ve been there because they leave jagged holes in the leaves (it looks like someone took bites out of the foliage) and they leave their telltale slime trails. I have seen them completely defoliate a new planting of marigold seedlings overnight…they have voracious appetites. You’ll be thrilled to know that slugs reproduce rapidly, laying hundreds of eggs a year. The eggs hatch in three weeks and baby slugs will start laying eggs when they’re only a few months old. Murphy’s Law of the Garden applies here: if it’s a “bad bug”, it can take over the universe in one season (somehow I think that the “good bugs” have a harder time of it….) Anyway, enough bad news, let’s getdown to business and learn about how we can save our gardens from these slimy pests!
First of all, clean up all garden debris to remove their hiding places. Remove the mulch from around the base of any plants that are affected. Replace the mulch with a ring of some substance that is sharp and crunchy–slugs won’t crawl over rough, scratchy material as it irritates their disgusting slimy bodies! I have used diatomaceous earth, a crusty white powder containing silica. Other folks that I’ve talked to have used wood ashes, shredded briar stems, human hair, eggshells, sand, sharp gravel or stone dust. Other physical barriers to slugs include copper strips (copper emits a weak electrical charge that shocks the slugs), or collars made of window screen or hardware cloth.
The most effective slug control on the market is iron phosphate, sold by the brand name Sluggo. This is a very safe bait that contains the active ingredient iron phosphate, which occurs naturally in the soil. Sprinkle it around plants that are being eaten. An effective early control to prevent the first generation of slugs from breeding in the spring is to sprinkle Sluggo in a band and cover it with a long board. In the morning, lift the board, discard the slugs, and repeat this process again the following evening. Do this until you don’t see slugs any more. Vigilance in the spring means fewer generations of slugs will survive to breed all summer long! The third line of defense is to spray the slugs with either a 50% vinegar and water solution or with fresh lime juice–both will kill them. Many people simply sprinkle salt directly on all the slugs that they find and watch them melt away like the wicked witch of the west. What fun!
The fourth line of defense is to trap them. Put down halves of grapefruit or orange rinds…in the morning, the slugs will have found them and you can toss them in the garbage. Or you can make the famous BEER TRAPS. Take an old tuna can, sink it in the garden so that the top is at ground level. Fill with the cheapest beer you can buy (or use a little bit of very good, yeasty beer, and drink the rest and toast the slugs goodbye…). In the morning, the can will be filled with dead drunk slugs and then it is your lovely job to discard them and set the trap again. Actually, the slugs don’t care what kind of beer you use; they are really attracted to the yeast in the beer. There are many commercial slug traps on the market featuring yeast baits.
What do I do? Besides using Sluggo, I handpick slugs and sometimes I drop them in a bucket of salt water. Usually though, I put them on a rock and stomp on them, or toss them onto the road…fried slugs, what a concept! It almost sounds like something to be served in a fancy French restaurant!
In an effort to provide horticultural information, these educational documents are written by Nancy DuBrule-Clemente and are the property of Natureworks Horticultural Services, LLC. You are granted permission to print/photocopy this educational information free of charge as long as you clearly show that these are Natureworks documents.