Each week, we pick a question that we get through our Master Gardeners hotline and write an article for the popular, online magazine Rural Intelligence. Below is this weeks article.
Slugs. Slimy, boneless, legless, and, for the most part, disgusting. Slugs are a type of gastropod mollusk — they are basically a snail without a shell and, like snails, love damp, shaded areas. You know what else likes damp, shaded areas? Hostas! I’ll give you one guess as to who is defoliating and chewing those big holes in your hosta leaves (see example of one plant being terrorized below).
As we all know, this year has been soggy and although we might not like it, your garden slugs are loving life. If you have a slug problem and don’t do anything to get it under control, they can really wreak havoc on not just your hostas, but on the rest of your garden as well. Slugs also like lettuces, strawberries, corn, beans, your flower garden — you name it.
Fortunately, fighting slugs can be done with a number of non-toxic means. Chances are, you aren’t going to completely eradicate slugs, but you can win the war.
Search and Destroy
Slugs eat mostly at night so if you are using this method, get your flashlight and head out after dark. There are a couple of ways that you can do this. Bring a pail of saltwater with you and physically pick off the slugs you see on your plants, tossing them into the salt water to drown. If touching their slimy, cold, grey, freaky bodies grosses you out, mix one part ammonia to six parts water. Put it in a spray bottle, aim, and shoot. The solution will kill them in seconds. If you are going to hunt them, make it easier on yourself by setting out melon rinds or old vegetables and fruits. It will act as bait, luring the slugs out in greater numbers and into one location.
This technique is a lot less hands-on. One of the tried and true methods of slug control is the beer trap. Take a pie plate or similar shallow dish and set it in a hole deep enough that the opening of the container is level with the soil surface. Fill the dish up to about 80% full of beer. The slugs love the yeast and barley in the beer and, unable to resist, will go into the liquid and drown, unable to get out. Check the beer level day to day and add more as needed. Another good trap is to take an old jar (any old mayonnaise or peanut butter jar will do) and put in a couple of tablespoons of cornmeal. The jar keeps the cornmeal dry and the slugs will think it is a delicious treat. The corn meal will expand in their stomachs and kill them. You know what they say, “A moment on the lips…”
Creating a perimeter of unfavorable conditions around the slug infested plants is another effective method. Copper strips are one solution as the static electricity reacts with the slime the slug produces for locomotion, basically electrocuting them. If you’re looking for something less costly, sand works, too, as the tiny sharp edges of sand particles rip open the slugs’ bellies as they pass over the grains. Slugs also prefer alkalinity, so using things like coffee grinds and pine needles around your plants will help keep the slugs off.
If you are using the beer trap method consider this — do you have pets? If so, you might want to put up some type of cover around the trap so that your pets can’t get to it but the slugs can. I put out a beer trap with a generous pour a couple of years ago and my dog found it way before the slugs. It wasn’t long before he was drunk texting his ex, eating old take-out from the fridge, and passed out on the couch watching QVC. I learned my lesson.