Companion planting can be defined as the close planting of different species based on their ability to enhance one another's growth or offer some form of pest protection or other advantages. Sometimes this is a matter of choosing plants with different growth habits that don't compete with one another or those that have different nutrient needs that make efficient use of soil. Strategic companion planting is especially important in small gardens or wherever careful space planning is needed.
Good Neighbors for Potatoes
Potatoes are deep-rooting vegetables, which logically suggests that the best companions will be those with above-ground growth habits that do not infer with the root systems of the potatoes. Lettuce, spinach, scallions, and radishes are shallow-rooted veggies that are a good choice for occupying the spaces between potato plants. Because potatoes are harvested late in the season, the best choices for planting right around the potato hills will be early season vegetables that will be harvested well before you need to stomp around the garden to keep up the potatoes.
There are several plants that are said to enhance the flavor of the potato tubers, including chamomile, basil, yarrow, parsley, and tyme (they also welcome in beneficial insects). Beans, cabbage, and corn all will help potatoes grow better and hence improve the flavor of the tubers.
- Did you know? Beans and other legumes are good companion plants for most other vegetables, as they increase nitrogen levels in the soil. Beans and peas are regarded as the "universal donors" when it comes to companion plants.
Horseradish is said to make potatoes resistant to disease, and petunias and alyssum will also attract beneficial insects that feast on insects destructive to potatoes. Colorado potato beetles are a particular problem for potatoes, and among the plants that repel this damaging pest are tansy, coriander, and catnip.
Neighbors to Avoid
Avoid planting potatoes near anything in the nightshade family, or even in the soil where nightshade plants have recently been grown. This includes eggplant, peppers, and tomatoes. Potatoes are also part of the nightshade family, and hence they are susceptible to many of the same diseases. Planting nightshade species close together (either in space or time) creates optimal conditions for certain fungal and bacterial diseases to thrive. You should allow a full two years before replanting a nightshade plant in the same soil.
There are a number of plants that apparently increase the likelihood of potato blight. These include raspberries, sunflowers, pumpkins, squash, and cucumbers.
And some plants, for reasons that aren't clear, seem to stunt the growth of potatoes. These include asparagus, carrots, fennel, turnips, and onions.
Good Companions for Potatoes