Beating the Bugs
by VCE Agent Kirsten Conrad
The information here was originally published in a monthly column on pest control in Between the Rows – A Guide to Vegetable Gardening published by VCE in collaboration with MGNV.
Don’t miss Kirsten’s in depth online class:
What’s Eating My [Cucumbers, Tomatoes, Eggplant, Beans, Squash]? :
Insect Pest Management for the Vegetable Garden
Planning to Prevent Insect Pests & Grow Healthier Plants in Next Year’s Garden
Most of the planning you can do to create happy healthy gardens and prevent insect and disease problems in next year’s gardens starts with what you do in the fall after your garden for this year is done. Your garden’s best defense against plant pests is to have healthy plants! Healthy plants fight insects in several ways: They outgrow insect pests and outlast the life cycles of the pests, they produce enzymes that discourage insect attack, and they partner with companions in combinations that repel the bad guys and in some cases attract the good beneficial insects. Here are some fall and winter cultural controls that any gardener can do to maintain healthy plants; these are well known, but we take them for granted.
Build Soil: The addition of organic matter and other nutrient rich soil improvements will enhance nutrient availability, help build soil structure, and improve drainage and water-holding capacity resulting in healthier, more robust, and better performing plants. In some cases, improving soil health will also help the plants fight off insect pests.
Sanitation: Cleaning up dead leaves removes overwintering eggs that are laid on stems and leaves that die and, if left in the garden, serve to protect the early life stages of pests like spider mites and aphids. Another form of sanitation that we rarely think about is the need to remove adjacent weeds that harbor overwintering insects. Virginia Tech’s Pest Management Guide contains many pest-specific examples of cultural controls. Likewise, if you are willing to monitor them over the winter, you can use trap plants like horseradish or kale to collect populations of harlequin bugs, which can be killed or removed with the plants as they become infested.
Plan Your Crop Selection: Choose your variety with an eye to reducing pest populations. Choose hybrids that are selected for pest resistance. Study seed catalog descriptions. Purple kale has fewer pests than green kale. Butternut squash is most resistant to squash vine borer than other winter squashes. Choose crops like asparagus, beets, or onions that have few pest problems.
Plan for Companion Plants: Combining pungent herbs and flowers with your veggies will not only attract pollinators but will repel some insects and mammals too! Combining multiple kinds of vegetables will sometimes confuse predator bugs. Here are some tables that might help with your planning.
Plan for Crop Rotation: Don’t plant the same plant in the same place year after year. Put squash where your tomatoes were last year. Grow greens where your cucumbers were last year. It confuses the pests and pays dividends in managing crop fertility needs if you alternate crops of corn or onions that need a lot of fertilizer inputs with crops like peppers or beans that have lower needs in the following year.
Finally, experienced gardeners know that optimizing growing conditions will result in healthier plants and healthier plants usually have fewer pests.
Plan for Right Plant Right Place: Do you have an area that stays wetter than the rest of your garden? Put your rhubarb or your asparagus there. There is also an Asian vegetable called skirret carrot if you want to try something new. Do you have an area that stays dryer than the rest of your garden? Choose legumes of all kinds, mustard greens, sweet potato, peppers, and, yes, watermelon to name just a few.
Plan to Reduce Competition: Having to fight for both light and water takes energy that a plant can put into fighting insect pests. If this is a problem for you, consider installing a root barrier around your garden area.