Companion Plants Aid Potatoes

by Ken Lain, The Mountain Gardener, Watters Garden Center

Potatoes grow deep, suggesting the best companions are those with above-ground habits that do not interfere with the potato tubers. Lettuce, radishes, scallions and spinach have shallow roots perfect for occupying the spaces between potato plants.

Potatoes are harvested late in the season. The ideal companion plants around the potato hills are early-season vegetables harvested well before you dig up the potatoes.

Several plants are said to enhance the flavor of the potatoes, including dead nettle, horseradish and marigolds. Beans and other legumes are companion plants because they increase soil nitrogen levels.

Horseradish makes potato plants resistant to disease. Petunias and alyssum attract beneficial insects that feast on nasty bugs that attack potatoes. Colorado potato beetles are a particular problem for potatoes. Among the plants that repel this damaging pest are tansy, coriander and catnip.

Avoid planting these next to your potatoes: carrots, cucumbers, eggplant, fennel, okra, onions, peppers, pumpkins, raspberries, squash, sunflowers, tomatoes, tomatillos and turnips.

Good companions are: alyssum, basil, beans, cabbage, catnip, chamomile, coriander, corn, horseradish, lettuce, marigolds, nasturtium, parsley, peas, petunias, radishes, scallions, spinach, tansy, thyme and yarrow.

Reasons companions help:

Bug prevention: Many plants are famous for repelling insects from potatoes. Marigolds are ideal for this reason. Other plants attract beneficial insects that serve as predators of harmful insects.

Growth: Companion plants have similar plant food, light and water needs, which makes them easier to care for. Pairing plants with high water needs, for example, makes watering more efficient and ensures all plants receive the right amount of irrigation.

No competition: Plants often have complementary habits. Pairing tall upright plants with low-vining plants efficiently use garden space. Pairing deep-rooted vegetables with shallow-rooted vegetables offer similar efficiency.

Nutrient replacement: Some plants improve your gardens nutritional value. Legumes are companions because they make nitrogen in the soil available for many other plants.

Perfects soil: Plants either consume or replenish minerals in the soil, prevent soil depletion and reduce plant food needs. Examples include beans and peas adding nitrogen to the soil; broccoli and cabbage use nitrogen.

Flavor enhancer: Some plants enhance other edible plants’ flavor when grown close together.