Combining plants in your vegetable garden is both an art and science. The way you intermix plants creates an interdependent relationship that keeps plants healthier, lengthens the growing season, makes the most of the space you have and increases the harvest. Basic planting rules help, such as keeping taller plants behind shorter ones, and leaving the right amount of space between rows so the plants have enough room for root growth. You can also take an additional step, known as companion planting, which pairs crops based on their specific needs and common problems to enhance growth.
Make the most of your garden space with vertical cropping. Train vining plants like peas, cucumbers, pole beans and squash to climb up a trellis or fence. This frees valuable ground space that the vines would sprawl across with a support structure. Provide extra support for heavier crops like squash.
Plant crops in succession. Some like cool weather while others prefer warmer temperatures, and this fact can work to your advantage. Plant a cool weather crop like spinach. After the harvest, when temperatures are too warm for continued growth, plant a fast growing summer crop like beans. When cooler autumn weather arrives, take out the bean plants and sow more spinach. Succession plant makes the most of your garden real estate and increases the volume of your harvest.
Intercropping is another way to maximize your available space. University of Illinois Extension says faster growing vegetables can be interspersed between slow-growing crops for increased yield. Plant rows of lettuce or green onions between tomato plants, for example. The harvest of the slow-growing crops will be complete by the time the tomatoes start bushing out and need the space.
You can also interplant herbs and flowers for insect control. Many common herbs and flowers repel pests that feed on vegetable plants. Coriander, nasturtium, mint and garlic repel aphids, a common enemy of cucumber and pumpkin plants. Horseradish will protect potato crops from potato bugs. Sage and rosemary repel the cabbage moth. (You can also use herbs to repel pests from your patio. Basil, for example, repels mosquitoes and flies. A few pots of basil placed around the deck will keep you more comfortable.)
You can also mix plants in a way that is mutually beneficial. Heavy feeders such as cucumbers and potatoes, for instance, will benefit from the nitrogen that is added to the soil when bush beans are grown nearby. Onions benefit when growing near chamomile; corn and squash benefit from peanut plants; basil and okra enhance sweet peppers; and marigolds enhance the growth of tomatoes and beans.
A few other companion planting tips are in order. Bee balm in the vegetable garden will attract bees, which will help pollinate your food crops. Plant beets, comfrey and chamomile to add beneficial minerals to the soil. Grow basil and garlic near tomatoes to improve flavor. Grow clover to inhibit aphids and cabbageworms in your cabbage patch. Plant caraway for a season or two so its deep root system can loosen compacted soil. A Google search for “companion planting” will provide you with more information on how to benefit your garden.