If beetles have infested your landscape, you already know that they can make short work of destroying plant leaves. Although some beetles are harmless, and might even be helpful, some types can be extremely destructive. Flea beetles, cucumber beetles and Japanese beetles are especially problematic, destroying both vegetables and ornamental plants. Though it takes extra time and diligence, it's best to deal with them by natural means because insecticides will kill beneficial insects as well as destructive beetles.
Remove weeds and refuse from the planting area. When weeds are allowed to accumulate, they provide a food source for beetle larva. Keeping the area clean is one of the most important ways to control beetles.
Put 3 to 4 inches of mulch on the weeded area. This will prevent larva from moving from the ground to your plants, and will provide nutrients to the soil at the same time. Healthy soil and healthy plants will be more resistant to beetles.
Remove the beetles from the plants by hand. Beetles are slow-moving in early mornings, so this is the best time to find them. Arm yourself with a bucket of soapy water, shake the leaves and let the beetles fall into the water. The soap will keep them from escaping, and they will soon drown.
Remove all dead vegetation and rake any leaves as soon as the growing season is over. This will eliminate one of the beetles' favorite winter hiding places.
Rotate your garden crops every planting season. If beetles are particularly fond of one plant, moving the plant to a new location will discourage them.