Sow Bugs, Diatomaceous Earth, and Organic Vegetable Gardens

They are called by several different names-sow bugs, pill bugs, woodlice, doodlebugs, and roly-polies. These bugs are commonly found in small numbers in lawns and gardens. For the most part, they are no problem, but when they breed in large numbers in a small area they can overrun a vegetable garden.

Sow bugs most often live in areas where there are piles of old leaves or in beds covered with garden mulch. They thrive in moist areas and eat dead or decaying vegetation. If there are too many in an area, they will find new young shoots or tender leaves to eat. In a garden, this can spell disaster. Most gardeners want to find a way to keep them out of the vegetable garden.

Diatomaceous Earth for Garden Pest Control

Sow bugs have a great defense against predators. Their shells taste bad and most insect eaters leave them alone. The most likely predator is the woodlouse spider (Dysdera crocata). To keep down the numbers of sow bugs, gardeners are advised leave this reddish spider alone to do its job.

There are pesticides that kill sow, pill, and other crawling bugs. However, most people want to limit the use of pesticides in their gardens, even if the product is labeled as safe for use on edible plants. And pesticides are never used in organic gardens. Organic gardeners look to other types of pest control.

Here are some organic ways to control sow bugs:

• Reduce the amount of moisture
• Remove excess mulch or debris from the area around the garden
• In raised beds, replace wooden supports with stone
• Use corncobs or half cantaloupes to bait and remove
• Dust around the plants with diatomaceous earth.

A Natural Alternative to Chemical Pesticides

Diatomaceous earth is a good alternative to pesticides. This natural mineral substance is mined and then ground up into a very fine powder. It is nontoxic to humans and animals. Any crawling insect that moves over or into the powder picks up the dust. The dust kills the insect by damaging the outer shell and drying out the moisture inside.

Place the powder around the area or the plants that needs to be protected. Surround the perimeter of the garden. Dust the top of the soil or run the powder along borders especially wooden planks. Sow bugs often burrow in the moist soil along the side of a wooden riser. After they’ve burrowed in for the winter, this area can be dug up and removed.

The use of diatomaceous earth has a couple of disadvantages. One is that it must be kept dry to keep it in powder form. Of course, it is difficult to avoid wetting the diatomaceous dust in a garden. The gardener must reapply the powder periodically between waterings or after the dust cakes up. The other disadvantage is that the powder is not targeted just to sow or pill bugs. The use of diatomaceous earth will affect any crawling insect, such as ants.

Controlling Sow Bug Infestations

The presence of small numbers of sow and pill bugs is usually not a problem. They can just be left alone. However, large numbers of them may become a nuisance. They are especially damaging to the new growth of an early spring garden. Understandably, most people do not want sow bugs in their vegetable gardens. Diatomaceous earth is a helpful approach to controlling these garden pests.