Best and Worst Sweet Potato Companion Plants

Growing sweet potatoes offers a nutrient-dense harvest. To enhance the health and yield of these vining crops, many gardeners use companion planting—a practice where specific plants are grown near each other to create a more balanced garden ecosystem. Understanding which plants work well with sweet potatoes can lead to a more successful harvest.

Benefits of Companion Planting for Sweet Potatoes

Pairing sweet potatoes with the right neighbors offers several advantages. One primary benefit is natural pest deterrence, as certain companion plants release strong scents that can confuse or repel common pests like the sweet potato weevil, reducing the need for other control methods.

Some plants are also effective at attracting beneficial insects. Flowers can lure pollinators and predatory insects like ladybugs and lacewings, which prey on pests and help protect your sweet potatoes.

Soil health is another area where companion planting proves its worth. Legumes, for instance, fix nitrogen in the soil, converting atmospheric nitrogen into a form that plants can absorb. The physical growth habits of different plants can also be used to maximize garden space, pairing low, spreading sweet potato vines with taller, upright plants.

Best Sweet Potato Companion Plants

Aromatic herbs are useful partners. The strong scents from herbs like thyme, rosemary, and oregano can mask the smell of sweet potato vines, making it harder for pests like the sweet potato weevil to locate them. Summer savory is especially noted for its ability to repel this specific pest.

Members of the allium family, such as onions, chives, and garlic, are also effective. These plants release sulfur compounds that deter a range of pests, including aphids and some beetles. Their compact, upright growth means they can be interplanted between sweet potato rows without competing for sunlight or space.

Legumes like bush beans are excellent for improving soil fertility. They perform nitrogen fixation, enriching the soil with nitrogen that sweet potatoes use for foliage and tuber development. It is recommended to use bush varieties instead of pole beans, as the latter can create too much shade and compete for sunlight.

Beneficial flowers serve multiple functions. Marigolds are well-known for their ability to deter root-knot nematodes, microscopic pests that can damage developing tubers. Nasturtiums can act as a “trap crop,” luring aphids away from your sweet potato plants. Additionally, their vibrant colors attract pollinators and other helpful insects.

Root vegetables that occupy different soil levels can be good neighbors. Beets, parsnips, and carrots grow their main edible parts at a different depth than sweet potato tubers, reducing direct competition for space. Planting these alongside sweet potatoes allows for a more efficient use of the garden bed.

Plants to Avoid Planting Near Sweet Potatoes

Just as some plants are beneficial, others can create problems for sweet potatoes by competing for resources or attracting similar pests. Squash should be planted away from sweet potatoes. Both plants are vigorous growers with sprawling vines that will compete intensely for sunlight, water, and soil nutrients. They also attract some of the same pests, which can lead to larger infestations.

Sunflowers are another plant to avoid. They can release allelopathic chemicals from their roots and decaying leaves, which inhibit the growth of neighboring plants like sweet potatoes. Their tall stature also casts considerable shade, depriving the sun-loving vines of the light they need.

Fennel is known for its negative allelopathic effects on many other plants. It releases compounds that can stunt the growth of most garden vegetables, including sweet potatoes. To prevent these effects, it is best to plant fennel in a separate area of the garden.

Garden Layout and Spacing Tips

Sweet potato vines are known for their tendency to sprawl, so it is important to give them enough room to spread without smothering their neighbors. When interplanting, position upright companions like bush beans or onions in the spaces between the sweet potato rows to ensure they receive adequate sunlight.

Creating a protective border around the sweet potato patch is an effective strategy. Planting aromatic herbs or marigolds along the perimeter of the bed can form a defensive barrier. This arrangement helps deter pests from entering the area where your sweet potatoes are growing and keeps the garden organized.