
Though some may plant their gardens haphazardly (to each their own, I say) I like to create a plan and plant carefully for beneficial growth and insect control. With 40 years of vegetable gardening experience as my guide, here are a few things that I have learned along the way.
- Diversity in the garden (as in most areas of life) is healthier
- Some plants have a positive effect on others
- The results of these relationships are often as beautiful as they are productive
The following is a brief synopsis of what I have gathered on the subject of companion planting from books (Roses Love Garlic is my favorite), online blogs, friends, trial and error, and good old common sense. Some of this material is based on science and some on folklore. Take what works for you, be open to experimentation, and, above all, have fun. Whatever you decide to try, I think you will be pleasantly surprised by the results.
Good Companions
Members from this group of plants play well with others, bolster growth, and prevent disease or infestation from harmful insects. There is no 'wrong' way to go about companion planting (border planting, interplanting, etc.) and whatever you try is bound to produce better results than doing nothing. So be brave and dig in.
Asparagus - Tomatoes, parsley, basil, and nasturtium
Basil - Tomatoes, lettuce, and most garden crops
Beets - Chard, onions, broccoli, cabbage, Brussel sprouts, cauliflower, and bush beans
Bush Beans - Carrots, catnip, potatoes, strawberries, corn, and marigolds
Cabbages - Dill (attracts beneficial wasps) and tomatoes (cabbage moth caterpillar repellent)
Carrots - Radish, rosemary, chives, leeks, lettuce, onions, cabbage, and sage
Cauliflower - Dwarf Zinnias (the nectar attracts ladybugs and other protective predators)
Corn - Beans (fix nitrogen and attract beneficial insects), squash, peas, and pumpkins
Cucumbers - Nasturtium (repels beetles), squash, and corn
Eggplant - Peppers, tomatoes, potatoes, and green beans
Lettuce - Beets, carrots, and tall flowers (to provide protective shade)
Marigolds - All garden crops benefit from this flower's ability to deter aphids, beetles, nematodes, and other harmful insects
Melons - Marigolds
Nasturtiums - Beans, cabbage, potatoes, radishes, and cucumbers
Onions - Carrots, beets, and lettuce
Peas - Corn, cucumbers, radishes, beans, and squash
Petunia - Beneficial throughout the garden
Potatoes - Cabbages, corn, eggplant, peas, Sweet Alyssum
Radish - Lettuce, peas, and cucumbers
Roses - Chives and garlic
Rosemary - Cabbage, carrots, beans, and sage
Spinach - Radishes, eggplant, celery, and strawberries
Strawberries - Spinach, bush beans, and lettuce
Sunflowers - Cucumbers
Swiss Chard - Kale, onions, and bush beans
Thyme - Improves growth and flavor of most vegetable, so plant generously
Tomatoes - Basil, carrots, parsley, cabbages, chives, and marigolds.
Poor Companions
Also know as allelopathic plants, this group does not play well with others and its members should be located well away from other plants. Allelopathic plants release chemicals which can inhibit another plant's health, sometimes causing them to bolt and go to seed too early, retard their growth, or outright kill them or their seed. These harmful substances are released from the leaves, flowers, bark, or the soil surrounding the plant. The list of antagonistic plants is extensive. Some of the more infamous are: Fennel, Shasta Daisy, English Laurel, Elderberry, Eucalyptus, Sycamore, and Walnut trees.