Even with an armful of pesticides or the best organic garden plan, the home gardener should not expect that their vegetable and flower gardens will ever truly be "pest proof." Organic gardeners can reduce pest populations by encouraging beneficial predatory insects to take up residence in the garden; other methods include planting "trap crops" which attract certain pest insects away from their usual meal. For larger pests like rabbits and deer, the best deterrent is usually to design the garden at its inception to deny these animals entry to the garden.
Encouraging Beneficial Insects
Attract beneficial insects like ladybugs, lacewings and praying mantis by interplanting the vegetable garden with flowering plants. Good examples include nasturtium, lavender, cosmos, marigold, coneflower and hyssop. Most adult predator insects require a source of nectar for food, but their larvae will feed ravenously on pests like aphids, cutworms and larval forms of beetles.
Resist the urge to use broad-spectrum pesticides, as this will kill beneficial insects as well as pest bugs. Insecticide applications may actually make a pest problem worse over time, as many species of garden pest recover and regenerate much more quickly than their associated predator species.
Handpick cutworms, tomato hornworms, cucumber beetles and potato bugs as you see them. Though very labor-intensive, this method is among the most effective forms of pest control in small gardens.
Trap slugs by setting out dishes of beer or sugar water. Because over-mulched gardens provide excellent slug habitat, apply no more than an inch at a time during warmer months.
Plant a strip of "trap crop" to draw pests away from a targeted vegetable crop. For instance, planting the 'Blue Hubbard' variety of zucchini in close proximity to yellow summer squash draws cucumber beetles and squash vine borers away from the yellow squash. Trap crops not intended to be grown for harvest, and exist only to redirect pests.
Deterring Larger Pests
Erect deer fence around the kitchen garden by installing fencing at least 7 feet in height, angled outward at the top. A single strand of electric wire fence is a good deterrent in areas where deer populations are low; a double-strand at 15 and 30 inches is better in areas with higher deer populations.
Hang bags of human hair, animal waste, bar soap, blood meal, mothballs or commercial deer repellent on the garden fence at regular intervals. As deer become desensitized to the smell over time, bags should be replaced every several weeks with a different type of filler.
Prevent rabbits, moles, voles and other burrowing animals from gaining underground access to the garden by digging a 6- to 8-inch trench and inserting chicken wire or other wire mesh into the ground. Mesh should be bent outwards at the bottom several inches to increase the barrier's effectiveness. Bury the mesh, leaving several inches exposed above ground, and erect a 2- to 3-foot fence around so the mesh and fence overlap at ground level.