Companion planting with potatoes can help you grow a stronger crop with fewer pest problems, better use of space and less bare soil. The key is choosing partners that either repel common potato pests, attract helpful insects, or simply fit into the bed without competing for light, water and nutrients. This guide covers the best companions, the plants to keep away from your spuds, how to lay out a bed, and the mistakes that cancel out the benefits.
How Companion Planting Works with Potatoes
Potatoes are heavy feeders with a dense canopy and a root zone that spreads outward from the seed piece. Companion planting works in a few specific ways: a strong-smelling herb can confuse pests that find potatoes by scent, a flowering plant can draw in predatory insects, and a shallow-rooted or nitrogen-fixing neighbor can share the bed without taking much from the potatoes. Expect modest gains, not miracles. Good soil, consistent watering and crop rotation still matter more than any companion.
Best Companion Plants for Potatoes
These plants are the most commonly recommended partners for potatoes, and each has a clear reason to be there.
Beans (Bush Snap and Pole Beans)
Beans add nitrogen to the soil through root nodules, which helps the potatoes that follow in rotation and keeps the bed fertile. Plant bush beans 12 inches from potato rows so they do not shade the plants or compete hard for water. Many gardeners report that beans grown nearby see fewer aphids than beans grown alone, though the effect is not well documented.
Marigolds (French and Signet)
Marigolds are a traditional companion for many vegetables. French marigolds (Tagetes patula) are often planted around potato borders in the hope of deterring some soil nematodes and drawing in hoverflies whose larvae eat aphids. Plant them at the bed edges or between every fourth or fifth potato hill, roughly 12 to 18 inches apart.
Horseradish
Horseradish is sometimes planted at the corners of a potato bed because gardeners believe it deters Colorado potato beetles. The evidence is largely anecdotal. Horseradish is also aggressive and spreads by root, so keep it in a contained pot sunk at the bed edge.
Cabbage Family (Broccoli, Cabbage, Kale)
Brassicas are sometimes paired with potatoes because their strong scent can confuse pests that locate host plants by smell. Give them at least 18 inches of space from potato plants, since both are heavy feeders and will compete for nutrients if crowded.
Bush Basil and Thyme
Aromatic herbs such as bush basil and thyme are often grown along potato rows. Keep them low and compact so they do not shade the crop. Their scent is thought to mask potato plants from some flying pests, and they make a useful harvest in their own right.
Onions, Garlic and Leeks
Alliums are frequently recommended as companions because their odor may discourage certain beetles and aphids. Plant them at the bed edges rather than mixed through the hills, spacing them about 6 inches apart.
Nasturtiums
Nasturtiums act as a trap crop for aphids and attract beneficial insects. Plant them at the edges of the bed where they will not crowd the potatoes. Their trailing habit makes them useful as a living border.
Corn
Corn can be interplanted with potatoes in large plots as a windbreak and partial shade for heat-stressed tubers. Keep corn rows at least 24 inches from potato rows, and note that the two crops draw on the same nitrogen, so feed the bed generously.
Radishes
Radishes mature in about 25 to 30 days and can be harvested before the potatoes need the space. Sow them between potato hills in early season. They help use the bed fully while the potatoes are still small.
Plants to Keep Away from Potatoes
Some neighbors cause real trouble, mainly by sharing diseases, competing heavily for nutrients, or attracting the same pests.
- Tomatoes, peppers and eggplant: All are nightshades that share early and late blight, verticillium wilt and several pests such as Colorado potato beetles. Keep them at least 10 to 15 feet apart and never rotate them into the same bed.
- Squash, pumpkins and cucumbers: Their sprawling vines shade and crowd potatoes, and they compete heavily for water.
- Sunflowers: Their allelopathic root exudates are thought to inhibit potato growth, and their height shades the bed.
- Raspberries and blackberries: They can harbor verticillium and spread through root suckering.
- Fennel: Often cited as inhibiting many vegetables, including potatoes, so keep it in its own container.
Companion Planting Layout for a Potato Bed
A workable layout keeps companions at the edges or between hills rather than mixed through the rows. This makes watering, hilling and harvest easier.
- Plant potato seed pieces 12 inches apart in rows spaced 30 to 36 inches apart.
- Place marigolds or nasturtiums at the bed corners and along the outer edge.
- Set alliums (onions, garlic, leeks) about 6 inches apart along one side of the bed.
- Fill gaps between rows with radishes sown in early spring, then harvest them before the potato canopy closes.
- Keep taller companions like corn on the north side so they do not shade the potatoes.
Potato Companion Planting Checklist
Before you plant, confirm the following:
- Seed potatoes are certified disease-free and chitted (sprouted) indoors for 2 to 4 weeks.
- Soil is loose, well drained, and has a pH between 5.8 and 6.8.
- No nightshades, squash or sunflowers are planted within 10 to 15 feet.
- Companion plants are spaced at least 12 inches from potato rows.
- The bed has been prepared and enriched with compost. For soil details, see Preparing Garden Soil for Planting: A Practical Guide.
Companion Planting Quick Reference
| Companion | Main Benefit | Suggested Spacing from Potatoes | Watch For |
|---|---|---|---|
| Bush beans | Adds nitrogen | 12 inches | Shares water needs |
| French marigolds | Draws beneficial insects | 12 to 18 inches | Can attract some pests |
| Garlic and onions | May deter aphids and beetles | 6 inches apart along edge | Competes for nutrients if crowded |
| Radishes | Early harvest uses space | Between hills | Harvest before potatoes canopy |
| Nasturtiums | Trap crop for aphids | Bed edge | Spreads if unchecked |
| Tomatoes | None | Keep 10 to 15 feet away | Shares blight and pests |
Common Mistakes
- Expecting companions to replace basic care. Potatoes still need consistent water (about 1 to 2 inches per week), hilling and pest scouting.
- Crowding the bed. Tight planting reduces airflow and increases blight risk.
- Planting nightshades nearby. Tomatoes and peppers in the same bed multiply disease problems.
- Forgetting crop rotation. Rotate potatoes to a new bed every three to four years to reduce soilborne disease.
- Letting invasive herbs spread. Mint and horseradish should be contained in pots.
Tips for Better Results
- Start with healthy seed potatoes and chit them before planting.
- Hill soil around stems when plants reach 6 to 8 inches tall, repeating every few weeks.
- Inspect the undersides of leaves weekly for Colorado potato beetle eggs and aphids.
- Keep a simple planting map each season so you can track which companions worked.
- For a full seasonal plan, see Vegetable Gardening Basics: Planting to Harvest.
FAQ
What is the best companion plant for potatoes?
Bush beans are among the most reliable choices because they add nitrogen to the soil and do not compete heavily with potatoes when spaced properly. Marigolds and nasturtiums are also widely recommended for their pest-related benefits.
Can I plant tomatoes next to potatoes?
It is not recommended. Tomatoes and potatoes are both nightshades and share diseases such as early blight and late blight, as well as pests like the Colorado potato beetle.
Do marigolds really keep pests away from potatoes?
The evidence is mixed. Marigolds attract beneficial insects and may reduce some nematode populations, but they are not a guaranteed pest control. Treat them as one part of an integrated approach.
How far apart should companion plants be from potatoes?
Most low companions such as marigolds, herbs and alliums do well at 6 to 18 inches from potato rows. Taller or sprawling plants like corn and squash need at least 24 inches or more.
Is garlic a good companion for potatoes?
Garlic is commonly planted around potatoes because its scent may deter some pests. Plant it along the bed edge about 6 inches apart so it does not compete heavily for nutrients.
Should I plant potatoes next to squash?
No. Squash vines spread widely and shade and crowd potato plants, and both compete for water and nutrients.
Can companion planting replace pest control?
No. Companion planting can reduce some pest pressure, but regular scouting, hand-picking beetles and rotating crops are still needed. For guidance on starting your bed, see How to Start a Garden: Site, Soil and First Plantings.
Conclusion
Companion planting with potatoes works best when you choose partners with a clear purpose, such as beans for nitrogen, marigolds for beneficial insects, or alliums for pest deterrence. Keep nightshades and sprawling vines well away, and space everything so the potatoes still get light, water and room to grow. Combine these choices with good soil, steady watering and rotation, and your potato bed will be healthier and more productive.
