It usually does not take long for insect pests to discover your garden. My newly planted asparagus patch lasted about two years before the asparagus beetles showed up. While we often think of spraying to control vegetable insect pests in the garden, both organic and chemical sprays have their disadvantages. They are not always effective and can kill beneficial insects, disrupting the ecological balance in your garden. It is always best to first try more low-tech ways to thwart pests. One way is to create barriers. If you can block insects from reaching your plants, they won’t lay eggs and you’ll reduce the infestation. Here are some barrier methods that have worked well for me over the years:
- Floating Row Covers: This white, cheesecloth like material comes in a variety of weights. Heavier versions are good for frost protection while lightweight versions are best for insect control. The material lets air, water, and light through, but blocks insects. You can grow vegetables that do not need cross-pollination, such as beans, broccoli, greens, and root crops, to fruition under a floating row cover. Simply place it loosely over the plants or use wire hoops to create a tunnel. Fasten it well to the ground so it does not blow away and so insects ca not get in. Check inside periodically for any stray insects.
- Aluminum Foil: I have had varying degrees of success with this method. For squash, you cant use floating row covers after the plants start flowering because the bees need to reach the flowers to pollinate them. To thwart squash vine borers, I place aluminum foil on the soil surface under the plant. The aluminum foil reflects light back into the air, and the flying squash vine borer insect adult can not find the vine to lay its eggs. I have also simply wrapped the stems of squash plants near the base with foil to prevent insects from laying eggs.
- Tarpaper or Cardboard: Cabbage maggot flies love to lay eggs on the base of the stem of cabbage and other related plants. The eggs hatch and the larvae feed on the roots, killing the plant. To prevent this damage, simply place a square of tarpaper or cardboard around the cabbage stem on the soil surface.