The Best Companion Plants for Sweet Potatoes (and What to Avoid)

Companion planting can make a meaningful difference in your sweet potato harvest—especially when it comes to managing soil, conserving moisture, and reducing pests. Over the years in my Sonoma Valley garden, I’ve learned which plants naturally support sweet potatoes and which ones compete or cause trouble. Sweet potatoes grow vigorously, but they benefit from the right neighbors and suffer from the wrong ones.

Here’s what has consistently worked—and what I avoid—based on my hands-on experience.

Table of Contents

Why Companion Planting Matters for Sweet Potatoes

Sweet potatoes are warm-season vines with two big needs:

Warm, loose soil for developing long roots
Space to spread their leafy canopy

Good companions either improve the soil, stay compact, or attract beneficial insects. Poor companions shade them, steal nutrients, or host pests that sweet potatoes attract.

Best Companion Plants for Sweet Potatoes

These plants pair well with sweet potatoes in my garden and help increase yields, reduce pests, or improve soil health.

1. Beans (Especially Bush Beans)

Beans fix nitrogen—just the right amount for sweet potatoes, which prefer low-to-moderate fertility.

Why they work:

Add mild nitrogen to the soil
Stay compact
Don’t interfere with vine spread

My experience:
Bush beans planted at the row edges help maintain soil health without overfeeding.

2. Herbs: Oregano, Thyme, and Mint (in Containers)

Sweet potato vines can overwhelm small plants. These tough herbs handle the heat and repel pests.

Best features:

Attract pollinators
Discourage flea beetles
Thrive in dry borders around beds

My note:
Mint only works in containers, never in the bed—it spreads even faster than sweet potatoes.

3. Marigolds

A classic companion—and one I rely on every summer.

Benefits:

Helps deter nematodes
Draws in beneficial insects
Stands up to summer heat

I plant marigolds at the corners of sweet potato beds where vines can’t easily swallow them.

4. Alyssum

Alyssum thrives in the heat and attracts hoverflies and lacewings, which help control aphids and whiteflies.

Why I like it:
It carpets the bed edges and doesn’t mind a little vine pressure.

5. Okra

Tall, heat-loving, and deep-rooted—okra pairs beautifully with sprawling sweet potato vines.

Why it works:

Doesn’t compete for root space
Provides some very light dappled shade
Thrives in the same warm conditions

I plant okra along the north edge of sweet potato beds so the vines stay in full sun.

Neutral Companions (Safe but Not Especially Helpful)

Peppers
Corn
Basil
Sunflowers

These plants don’t harm sweet potatoes, but they don’t offer notable advantages.

Plants to Avoid Around Sweet Potatoes

These plants compete for nutrients, create too much shade, or can lead to pest or disease problems.

1. Squash and Pumpkins

Both squash and sweet potatoes are sprawling vines. Together, they become a tangle that’s impossible to manage.

My experience:
I tried it once. Never again. Harvesting either crop becomes difficult, and both suffer from crowding.

2. Cucumbers and Melons

Fast-growing vines that compete for sun and space.

Problems:

Shading the sweet potato vines
Encouraging fungal diseases in crowded areas
Attracting cucumber beetles, which can also feed on sweet potato foliage

3. Tomatoes

Tomatoes demand rich soil and consistent feeding—too much nitrogen for sweet potatoes.

Issues:

Shading from tall tomato plants
Competing for water
Different fertilizer needs

I keep tomatoes in a separate bed where I can feed them heavily without affecting root crops.

4. Root Crops (Carrots, Beets, Radishes)

Root crops compete with sweet potatoes underground.

Why it’s a problem:

Crowded root zones
Forking or misshaped sweet potatoes
Reduced yields for both crops

Sweet potatoes need stretching room below the soil.

5. Anything Tall and Heavy-Shading

Examples: corn (if planted close), sunflowers, pole beans.

Anything that casts deep shade slows sweet potato growth dramatically.

Final Thought

Over the years, I’ve learned that sweet potatoes thrive with light, airy, heat-loving companions—plants that don’t crowd the soil or block the sun. Bush beans, herbs, marigolds, alyssum, and okra make great neighbors, while squash, tomatoes, cucumbers, and root crops should be planted elsewhere. Getting the companion planting right helps create a healthy, balanced bed that supports big, sweet, flavorful harvests every time.