Managing Soil Pests in the Garden is part two of three in the Garden Bugs series.

General Recommendations

Many soil insect pest populations reach high numbers in grass or turf, and home gardens are often established in areas previously covered with grass. To reduce soil insect problems, thoroughly till or spade the area well in advance of planting (30 days or more) and again just before planting.

This will bring up soil pests near the surface where their chances of mortality are increased. In most cases, tilling the soil or sod in fall and early spring will sufficiently control soil insects without the need for a soil insecticide.

If tilling is not an option, apply a broadcast soil insecticide 2 weeks before planting to help control some soil insects like  cutworms, wireworms, and white grubs. Check with your local Extension System office for available insecticides.

Slugs

Slugs like to feed on young seedlings and succulent parts of plants. They leave a trail of mucus on the surfaces on which they crawl. Moist, humid environments favor slug development, and slugs usually overwinter in sheltered locations outdoors. They deposit their eggs in moist areas and require a year or more to mature.

• Spade or till garden area in the fall and again in the spring before planting
• Pick slugs by hand. Using a flashlight, check the garden around 10:00 p.m. for active slugs. If you find any, pick them up with an old teaspoon. Place captured slugs in a container of salt which will kill them. Continue this activity for 3 to 4
  nights in a row to greatly reduce damage.
• Place stale beer in small cups or pans sunken in the soil so the lip of the container is slightly below ground level. Slugs are attracted to the beer, fall into the container, and drown. For best results, replace the stale beer about every 3 days. Setting
  out enough containers early in the spring can greatly reduce slug populations.
• Use diatomaceous earth, lime, or sawdust as a barrier; replace after each rain.
• Pesticide baits are minimally to moderately effective against slugs. To increase their effectiveness, apply them late in the afternoon. Bait in the fall after the first fall rains to target slugs before they can lay eggs. Check with your local Extension
  System office for available pesticide baits.

Slug

Cutworms

Cutworms are active only at night and remain buried below the soil surface near food plants during the day. They emerge to feed at night and often cut seedlings or small stems, causing the plants to fall over.

• Because grass and many weeds are preferred hosts, remove grass and weeds in the garden, and plow the soil well in advance of planting.
• You can also prevent damage by placing a paper or plastic “sleeve” over the plant and pressing the bottom into the soil.
  Place sleeves around newly set transplants or newly emerged seedlings so that 1 inch is below ground and 3 inches above ground. Paper cups with the bottoms removed or 4 inch high sections of 1⁄2 gallon paper milk cartons are ideal. Tuna cans
  with the bottoms removed may also work.
• Check with your local Extension System office for available insecticides.
• Use Sevin bait after plant emergence. Apply Sevin according to label directions late in the afternoon so the bait will be fresh when the worms come out to feed at night.

Cutworm

Wireworms

Wireworms are the slender, yellowish brown, hard-bodied larvae of click beetles. They can survive deep in the soil for up to 5 years and can move up to attack seed or young plants. Several wireworm species prefer plants in the grass family and are
usually not a problem unless the garden is planted into land that previously contained grasses or crops in the grass family.

• Turn over the soil in the fall, and again in the spring well in advance of planting, to help reduce wireworm populations.
• Use a granular insecticide. Apply granules according to label directions, and work then into the soil to a depth of 4 to 6 inches, followed by a good watering.

Pacific Coast Wireworm

White Grubs

White grubs are Japanese, May, and June beetle larvae that are dirty white in color. The tip of their abdomen is a blue-black color. They roll into a C shape when disturbed. Mature grubs may reach 2 inches in length. They live in the soil and sometimes feed on plant roots and tubers. About the only time they are troublesome is when parts of the lawn or sod are turned under in the spring for garden use.

Lined June Beetle

• If you must plant in previously grassy areas, prepare the garden well in advance of planting. As sod is turned over, raked, and prepared for planting, pick up the grubs by hand for the best control.
• Check with your local Extension System office for available insecticides.

Mole Crickets

Mole crickets have brown, velvety bodies with broad front legs for digging in the soil. They have large eyes and are about 1 inch long when mature. As mole crickets tunnel through the soil, they can disrupt the root system of vegetables. They may also feed on plant root and underground stem tissue.

• Avoid planting the garden in previously grassy areas. If you observe mole cricket tunnels around plants, tamp the soil back down to restore support to the root system.
• Check with your local Extension System office for available insecticides.

Mole Cricket

Trade names are used only to give specific information. The Alabama Cooperative Extension System does not endorse or guarantee any product and does not recommend one product instead of another that might be similar.

Garden Bugs Series

• Making Your Garden Vegetables Less Susceptible to Insect Damage
• Managing Soil Pests in the Garden
• Managing Above-Ground Pests in the Garden

Download a PDF of Garden Bugs, ANR-1045.