Slugs

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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 plants. 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. 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. What’s an organic gardener to do?

 

First of all, clean up 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 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. All of these methods can affect your plants. Be careful.

 

The fourth line of defense is to trap the slugs. 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 BEER TRAPS. Take an old tuna or cat food 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 slugs and then it is your 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.

 

Strive to create a balanced habitat in your yard. Slugs are eaten by many beetles, toads, snakes, turtles, ducks, and many birds.

 

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.