Garden Help Desk: Correct watering, traps and more can help alleviate snail problems
We are having a terrible time with snails and maybe slugs in our garden. I see snails sometimes in our home orchard, too. We’ve used snail bait, but it doesn’t last very long, so we need to replace it often. I planted my tomato transplants and the next day the plants had been eaten by snails. There was nothing left but little green stems. I bought new transplants, but I don’t want to have the same thing happen to them. What can we do?
You know you have snails because you’ve seen them, but for readers who may be seeing damage but not the culprits, if you’re seeing smooth-edged, irregular holes in leaves, small seedlings or transplants clipped off or missing, and shiny trails on the soil or hard surfaces, you probably have snails or slugs feeding in your landscape.
There are a few things you can try for slug and snail problems.
First, as much as possible, reduce moisture and shelter in your landscape. With most of the emails I get about slugs and snails, excess moisture from watering is a large part of the problem.
- No plant debris, clutter, coiled hoses, etc., left on the ground.
- No plant foliage resting on the soil. Keep things pruned just enough to prevent this.
- Fix areas where moisture can collect — level soil, redirect water, etc.
Water deeply but very infrequently. For the trees, water deeply but not more than once every seven to 10 days during the summer and less often in the spring and fall. For your lawn, water deeply but not more than once every four to five days during the summer and less often in the spring and fall. For the garden, water deeply but not more than once every three to five days during the summer.
Deeper watering is the key to watering less often. If needed, you can also spread about an inch of compost over the soil to act as a mulch.
When I got a little more information from you, you mentioned that you are watering with pop-up sprinklers. Using drip irrigation in your garden (and in your home orchard next to your garden) will make a difference with your snail problem. You’ll only be putting moisture where your plants need it.
Second, start handpicking snails. You may be tempted to just step on snails when you see them, but snail eggs can continue to mature and hatch even after the parent snail is dead, so handpicking is a better choice. Yes, handpicking is inconvenient and has a high “ick” factor, but it’s a very effective method. Go into the garden with a bucket of soapy water every day and collect as many snails as you can find. After several days, you’ll probably notice that it’s getting harder to find snails. At that point, scouting for snails once or twice a week should be enough. Snails like to feed at night, so going out with a bucket and a flashlight after dark is usually successful.
Third, use traps. Pieces of scrap lumber (broken pieces of wide fence pickets, for example) that are elevated about an inch above the soil, or anything similar that creates shade and leaves just enough room for a snail to get underneath, will provide the shelter that snails seek out. They’ll shelter there during the day, and you can easily collect and dispose of them.
Fourth, continue to use bait, but protect the bait in bait stations. Your sprinkler irrigation dilutes your chemical bait, making it less effective. You can purchase ready-made bait stations or make your own by cutting snail/slug-sized openings in the sides of milk cartons, larger deli containers or other items that will protect the bait from rain and irrigation. Position the openings so they are easily accessible to the snails but don’t admit rain or sprinkler spray. Check frequently and refresh bait as needed.
Place your traps and bait stations where you see plant damage or other signs of snail or slug activity.
Fifth, apply a thin barrier of diatomaceous earth (DE) around your vegetable plants to discourage snail feeding. Refresh the DE whenever it gets wet.
When you replant your small transplants, you might consider protecting them with tall “collars” made from paper or plastic cups that have the bottoms removed. Set the tubes over the transplants and push them just a bit into the soil. Use a rubber band to secure fine mesh or screening over the top of the collar until your transplants are large enough to outgrow the collar and withstand a little slug feeding.