Have you recently observed your vegetable and flower seedlings being devoured overnight?

Or seen large holes in the leaves of your plants, or irregular edges on some of the leaves that you know aren’t supposed to be there?

If so, it may be time to get your hunting gear together. And in this case, you won’t need a hunting license, but you may need a little determination and perseverance. Your garden could very well be infested with snails, slugs or earwigs.

Finding these pests may not be easy. They like to feed at night and hide during daytime. They like to hide in moist places, preferably in protected areas such as under leaves, pots or boards.

Snails and slugs chew smooth-edged irregular holes in the leaves and flowers of a variety of plants. They prefer succulent foliage and flowers.

Earwigs especially like new seedlings or the growing shoots of plants. In fact, the plants may be missing all or part of their leaves or stems or, on older plants, the leaves may have many irregular-edged holes chewed in them.

Snails and slugs are very similar except that snails carry coiled shells on their backs. The brown garden snails are the most common type in our area. They have two long tentacles protruding from their heads to sense their surroundings and two eyes located just below the tentacles.

Snails move by gliding along on a muscular foot containing a large, rasping mouth that chews by grating and scraping. Below the mouth is a gland that continually secretes mucus, thereby leaving a silvery, slimy trail in its path. This slime is a good indication that you have snails in your garden.

Plants that snails and slugs particularly like include basil, beans, cabbage, dahlias, delphiniums, hostas, lettuces and marigolds. They also enjoy ripening fruit such as strawberries, artichokes and tomatoes that are close to the ground. Plants that they rarely bother include begonias, California poppies, fuchsias, geraniums, impatiens, lantana and nasturtiums. Also resistant are plants with stiff leaves and highly scented foliage, such as lavender and rosemary.

One way to trap snails and slugs is to lay flat objects on the ground in the early evening, such as boards that they can crawl underneath when they hibernate during the day. Place the flat object in a moist area, propped up with small rocks or pieces of wood to allow the snails to crawl underneath for protection. The next morning, collect the snails by scraping them into a bucket of water or crushing them.

Another way to catch them is to use a beer-baited trap: a small can sunk into the dirt with the upper edge at ground level and filled partially with beer. The can must have deep sides so the snails can’t escape after falling in. They love beer and aren’t particular about the brand.  

Most people can recognize earwigs by the prominent pair of pincers protruding from their tail. The most common species in our gardens are the European earwigs. They are approximately 3/4 inch long and reddish brown in color. They use their pincers for defense. However, in spite of their treacherous appearance, they do not attack humans. In fact, they can also be beneficial in that they like to eat aphids. They feed at night and hide during the day under loose clods of soil, boards, pots or dense vines.

To trap earwigs, set out flat objects, such as boards, directly on the ground in the evening. They will hide under these traps after feeding at night. However, when you overturn the traps in the morning, you must be quick to capture them, since they rapidly scurry away.

Another technique is to place a low-sided can, such as a cat-food or tuna can, in the infested area. Put 1/2 inch of oil in the bottom, preferably oil from the tuna or cat food. The earwigs will climb in and drown.

Metaldehyde pellets are a particularly effective bait for snails, slugs and earwigs. Sprinkle the pellets in infested areas, especially around the plants themselves so the pests have to encounter the pellets to reach the plants. Do not use pellets in areas accessible to children and pets. Some metaldehyde products also contain carbaryl to increase the range of pests controlled. Most nurseries carry these products.

Silvfast is a Napa County Master Gardener.