Garden Slugs Are Eating My Peppers and Tomatoes

Peppers (​Capsicum​ spp.) and tomatoes (​Solanum lycopersicum​) are two common plants eaten by slugs. Although these plants typically are grown as annuals, tomatoes and some types of peppers, such as the habanero, are herbaceous perennials in USDA hardiness zones 10 and 11. Slugs feed on the lower leaves of young plants and the ripening fruit and are typically found in gardens that have moist or shady conditions. They primarily feed at night or during overcast and rainy days with their file-like mouthparts tearing plant tissue as they chew. Biological, mechanical and chemical controls offer numerous options to assist in eliminating your slug problem and saving your peppers and tomatoes from their slimy attack.

Slugs along snails hold the honor of being one of the most damaging pests gracing gardens with their destructive behavior, according to UC-IPM. Both use a "muscular" foot to glide along and secrete mucus that assists in their movement that dries leaving a silvery slime trail letting you know they were there. The basic difference between a slug and a snail is the slug doesn't have a spiral shell covering like a snail. Depending on the type, slugs mature in around three to six months, laying anywhere from three to 40 round or oval translucent eggs in cracks in soil or other protected locations in the landscape.

Slug damage is identifiable by the irregularly shaped holes they leave on plant leaves. Usually, they feed on leaves that hang closer to the ground and tend to favor younger, more tender leaves. They can, however, crawl further into the plant and feed on upper leaves as well with damage often noted after rains or heavy irrigation.

They are attracted to the scent of ripening fruit and can be found feeding on peppers, tomatoes, as well as other fruits and vegetables throughout the season, as well as ornamental plants. Slugs are actively doing their damage from spring until the season's first frost, according to Clemson University, when they hibernate in the soil. However, those living in areas with mild winters can experience slug activity year-round. Slug activity also decreases during dry and drought-like conditions.

Nonchemical controls for slugs include setting traps and applying barriers. You can make traps from flat boards or wet newspaper baited with a piece of potato or cabbage placed underneath and be sure to remove the slugs attached to the bait daily. Traps can also be as simple as a lid or bowl buried in the garden so that the top is flush with ground level. Water with yeast or beer placed within the trap attracts the slugs and they enter and drown. Barriers of copper or diatomaceous earth spread around the perimeter of a garden prevent slugs from entering as well.

Chemical control includes beneficial compounds such as iron phosphate, which if unconsumed by slugs adds fertilizer to your garden, or nonbeneficial compounds such as metaldehyde. Slug killers that contain the compound mesurol are effective for ornamental applications, but should not be used around edible crops such as tomatoes and peppers due to its toxicity. Always read the product label and use it as directed following any precautions.

Stop slugs eating your peppers and tomatoes by selecting planting sites less conducive to their presence. A well-draining site in full sun is best for fruit production and is inhospitable for snails and slugs. Switching to drip irrigation instead of sprinkler or overhead irrigation also deters slugs by keeping the foliage dry and delivering needed moisture directly to the plant's root system. Remove debris from the garden before planting or after the season by raking out leaves and dead plants as this also helps to remove any slug eggs that would have overwintered in your garden.

You can draw slugs out of their hiding place by watering the area with slug or snail activity in the late afternoon. Once it gets dark go back into the garden with a flashlight and hand-pick all the slugs you find and place them in a bucket of soapy water. Doing this daily will soon have your slug problem under control.