Sweet potatoes are by far one of my favorite crops. They are challenging to grow in the north but not impossible so long as you’re willing to protect from the cold to extend the season. They make a significant long-term storage food source as a crop, so we plant in our vegetable patch them every year to help fill our cold room. But getting that bountiful harvest requires more than a long growing season. Try growing some of these companion plants alongside your sweet potato vines to get the healthiest plants.
The Benefits of Companion Planting Sweet potatoes
Companion plants bring many benefits to the garden. Flowers, vegetables, and herbs can all contribute to the health of an organic garden. These benefits of companion planting sweet potatoes include:
Attract pollinators: Sweet potatoes bright flowers attract bees. Those pollinators will help increase overall yields in your vegetable gardens.
Help improve the soil: The dense foliage of sweet potato plants provide a living mulch to help keep the soil cool and moist.
They help control weeds: Planting sweet potatoes under tall or trellised plants like pole beans creates a living mulch that will help control weeds by not allowing much space for the weeds to grow.
Companion planting can help with disease issues. Diseases are spread more quickly through your garden when plants of the same type are grown in a large grouping. Adding different species throughout the planting can help break up the garden and slow the spread of diseases like powdery mildew or blight.
You can see from this list that sweet potatoes make an exceptional beneficial plant interplant in your garden.
See: Companion Planting
Quick sweet potato Planting & Care Tips
Ipomoea Batatas (sweet potato vine) is a bright orange flesh tuber with a sweet taste and silky cooked texture. These tropical plants originated in Central and South America, so you know they like warm weather.
Planting out: Plant out young potato plant slips two weeks after the last frost in your area when the soil temperature has warmed to at least 80F. I can’t stress enough that they need warm soil. Plant slips 6 inches deep and 12 inches apart. Sweet potatoes take up a lot of space, so don’t crowd them.
Soil requirements: Sweet potatoes produce best in well-drained, light, sandy soil.
Sun requirements: Sweet potatoes require full sun.
Growing season: Sweet potatoes take 90-165 days to grow, and they are incredibly frost-sensitive. Start them in early spring, as soon as the soils is warm enough to ensure as long as possible growing season.
Fertilizer: Work 2 inches of compost into the soil before planting the slips. Sweet potatoes need potassium and phosphorus throughout the growing season, so be sure to use a quality fertilizer that contains both of those nutrients. You can also side-dress your plants with additional compost through the season to ensure healthy, hardy growth.
Harvest time: Harvest the tubers in late fall before the first frosts. In North America, sweet potatoes grow very well in the south, but you will need to use season extenders like greenhouses or hoop houses to grow mature tubers in the north.
The Quick List of Sweet Potato Companion Plants
These are the plants that partner well with sweet potato tubers and vines:
- Green onions
- Summer savory
Companion Planting sweet potatoes in The Vegetable Garden
There are so many wonderful vegetables that you can plant along with sweet potatoes that offer incredible benefits to help keep your sweet potatoes growing healthy and strong.
Nitrogen-fixing plants like pole beans, green beans, peas, and bush beans make great companion plants for sweet potatoes. The plants can be trained to trail along with the sweet potato vines through the garden rows or beds.
You can also plant your sweet potatoes in front of a bean trellis and allow the vines to create a living mulch under the beans. Both plants will benefit significantly from this planting plan – the beans provide nitrogen for growth, and the vines keep the soil cool for the beans.
Spinach acts as an effective ground cover that helps to prevent weeds. The bushy habit of spinach also helps shade the ground around the sweet potatoes keeping the soil cool and moist.
Root vegetables like radishes, carrots, potatoes, and beets make excellent additions to sweet potato beds. The plants all enjoy the same growing environment and can grow side by side without negatively impacting the other.
Radishes can also act as a trap crop for flea beetles, which will help protect the vines.
Alliums such spring onions, scallions, leeks, onions, and green onions are good companion plants to sweet potato. They take up little or no space between rows and do not negatively impact the growth of the sweet potato tubers due to their small root systems.
Companion Planting Sweet Potatoes with Flowers
Several flowering plants work great planted in the vegetable garden interplanted with sweet potato vines.
Nasturtiums are among the best companion plants to interplant with your sweet potatoes for several reasons.
The flowers look lovely twining with the sweet potato vines along the ground. The flowers of Nasturtiums add a beautiful pop of color to the garden that helps to attract beneficial insects like bees.
Nasturtium plants and vines make lovely ground cover providing shade to the soil and helping to prevent moisture loss.
Marigold’s bright colors and abundant food sources attract bees and other beneficial insects to the garden. Those pollinators will help increase yields in your vegetable gardens, which makes them good companions for sweet potatoes.
The flowers also attract helpful insects like parasitic wasps and ladybugs.
Marigolds’ strong scents act as pest control for common garden pests such as the notorious squash bug making them an excellent companion plant. In addition, marigolds attract slugs and spider mites, making them a good trap crop to keep these pests away from your veggies.
Turning the flowers into the ground at the end of the season helps kill pests like root-knot nematodes.
Alyssum creates a dense ground cover that helps prevent weeds and keeps the soil moist.
The shallow roots of the alyssum plants also have no negative impact on the growth of the sweet potato tubers making them a good companion plant.
The fragrant flowers attract beneficial insects like bees and parasitic wasps.
Plus, nothing smells as good as alyssum flowers in bloom!
Companion planting sweet potatoes with Beneficial Herbs
Basil planted with sweet potato is said to improve the sweetness of the tubers. While in bloom, basil also attracts pollinators.
The lush, bushy growth of basil helps to shade the ground, which helps to prevent the evaporation of moisture.
Densely planted, basil will also help prevent weeds.
Thyme is a perennial herb that attracts hoverflies, which eat destructive aphids.
Like basil, thyme will improve the taste of the tubers.
Herbs like dill, chives, borage, summer savory, and oregano make good companion plants for sweet potato vines. Plant these aromatic herbs nearby to ward off the destructive sweet potato weevil.
Herbs in bloom will also attract pollinators and helpful insects.
What not to plant next to sweet potatoes
Although sweet potatoes have an abundant array of companions, a few plants should not be grown near the precious potato plants.
Tomatoes and potatoes planted near each other increase the chances of both plants contracting potato blight.
Sweet potatoes and tomatoes also share many pests like spider mites and aphids. Planting them together creates an environment where pest infestations can take over and destroy plants.
Squash, pumpkins, gourds of any kind makes poor companion for sweet potatoes because they compete for space and nutrients. This competition will negatively impact the growth of both vegetables.
When planted near potatoes, sunflowers increase the chance of potatoes contracting a fatal disease called potato blight.
Sunflowers are allelopathic; that is, they give off toxins (terpenes and various phenolic compounds) from roots, leaves, stems, flowers, and even seeds. The toxins will impede the growth of sweet potatoes.
It is best to plant your sunflowers far away from your sweet potato rows.
Create a healthy garden by planting companion plants
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The key to companion planting is to understand your challenges before planting. You can see from this list how specific plants and plant combinations work well in the garden. But you do need to consider the “why” before you add a companion plant.
For example, there are some wonderful companion plants for sweet potatoes that you may consider first, like basil for flavor or nasturtiums to prevent pests.
Companion planting is more complicated than simply adding in plants; you should consider the specific benefits for your garden before planting.
If you want more information about companion planting, I highly recommend the book ” Carrots Love Tomatoes.”
Looking for more Companion Planting Inspiration?
Nope! Although in the US the terms are used interchangeably, yams and sweet potatoes are completely different vegetables.
Yams are starchier and usually not as sweet as the orange-fleshed sweet potato.
Sweet potatoes are easily identified by the exterior colors. The skins can be rose or purple colored. Yams, by comparison, have copper tan skin with creamy white flesh.
With ideal conditions, you can grow 5-10 tubers per sweet potato slip.