Potato Companion Plants
Solanum tuberosum · nightshade family · rotation group: nightshade
The best companion plants for potato are Bush bean, Horseradish, Cilantro, Sweet alyssum, and Sweet corn. Avoid planting potato near Tomato, Pepper and eggplant, Sunflower, Squash and cucumber. Of the 11 pairings recorded here, 2 are supported by published research and 8 are traditional practice with no controlled evidence behind them.
What to plant with potato
| Plant | Claimed benefit | Evidence | What the evidence actually shows |
|---|---|---|---|
| Bush bean | Bush beans interplanted with potatoes deter Colorado potato beetle and enrich the soil. | Traditional | No controlled trial supports the beetle claim, and the soil-enrichment half is not supported either: same-season nitrogen transfer from legumes to neighbouring plants is minimal. |
| Catnip | Catnip repels Colorado potato beetle and flea beetles. | Traditional | Nepetalactone has documented repellency against some insects in laboratory assays, but garden-scale protection of potatoes has not been demonstrated. |
| Cilantro | Flowering cilantro attracts predators and parasitoids of Colorado potato beetle and aphids. | Traditional | Flowering umbellifers do support natural enemies in general, but no potato-specific trial was found. |
| Horseradish | Horseradish planted at the corners of a potato patch improves plant health and deters pests. | Traditional | A very old and very widely repeated recommendation with no controlled data behind it; horseradish is also aggressively perennial, which is a practical argument against it. |
| Sweet alyssum | Sweet alyssum feeds hoverflies and parasitoids that suppress potato aphids. | Traditional | Strong evidence exists for this insectary plant in lettuce; the potato application is a reasonable extrapolation, not a tested result. |
| Sweet corn | Corn shelters potatoes and shares the bed without competing. | Traditional | Both are heavy feeders and corn casts significant shade; this pairing is a convention with no evidence and a real competition risk. |
| Marigold | Marigolds planted among potatoes repel Colorado potato beetle. | Not supported | Directly contradicted: UMN Extension states that multiple studies have shown this to be untrue, and Rutgers work found marigolds failed to repel cabbage, carrot and onion pests as well. |
What not to plant with potato
| Plant | Claimed problem | Evidence | What the evidence actually shows |
|---|---|---|---|
| Pepper and eggplant | Other nightshades near potatoes share soilborne disease and beetle pressure. | Research-backed | Same family, same Verticillium and early blight hosts, and Colorado potato beetle feeds on all of them; the rotation rule follows directly from documented host range. |
| Tomato | Potatoes and tomatoes grown together amplify early blight, late blight and Colorado potato beetle. | Research-backed | Documented rather than folkloric: Alternaria solani and Phytophthora infestans both infect the two crops, inoculum survives in soil and debris, and extension management for both is built on separation and a 3-4 year nightshade rotation. |
| Squash and cucumber | Cucurbits near potatoes worsen blight. | Traditional | The two groups share no significant pathogen; this appears to be competition-for-space advice that was restated as a disease rule. |
| Sunflower | Sunflowers suppress potato growth through allelopathy. | Traditional | Sunflower allelopathy is documented against some weeds in laboratory and field studies, but its effect on potato specifically has not been tested. |
The honest verdict
None of the companion pairings commonly recommended for potato have been confirmed in controlled trials that we could find. That does not make them harmful — it means the benefit is unproven, and you should plant for spacing, sun, and water compatibility first.
The remaining 6 pairings on this page are traditional practice. They circulate on every companion planting chart online, but we could not find controlled evidence testing them. They are not wrong so much as unverified — most cost nothing to try, and interplanting flowers and herbs has its own well-documented benefit of pulling pollinators and predatory insects into the garden.
Widely repeated, not supported: Marigold — Directly contradicted: UMN Extension states that multiple studies have shown this to be untrue, and Rutgers work found marigolds failed to repel cabbage, carrot and onion pests as well.
Every row above links to the publication it came from. See how we grade evidence.
Growing potato: the numbers
| Sun | Full sun (6+ hours) |
|---|---|
| Water | Moderate |
| Spacing | 12 in apart · 33 in between rows |
| Mature size | about 24 in tall |
| Soil pH | 5–6.5 |
| Days to maturity | 70–120 days |
| Frost tolerance | Half-hardy — takes a light frost |
| Containers | Yes — 15 gallon minimum |
| Typical yield | 2-4 lbs |
| Common pests | Colorado potato beetle, flea beetles, aphids, potato leafhopper, wireworms, cutworms |
| Common diseases | common scab, early blight, late blight, Verticillium wilt, Rhizoctonia (black scurf), mosaic virus |
When to plant potato
Zone 6b shownDirect sow outdoors: Mar 20 – Apr 2 — 3 weeks before last frost
Expected harvest: May 29 – Jul 18 — 70–120 days from planting
Those dates are for zone 6b. Get your own dates by ZIP code →
Varieties worth knowing
seed potatoes- Yukon Gold — yellow-fleshed all-purpose, early to midseason, ~70-90 days from emergence
- Kennebec — white, late main-crop, high-yielding storage type, 100+ days
- Red Pontiac — red-skinned midseason, widely adapted and heat-tolerant, 85-100 days
- Russet Burbank — russet, late, the commercial baking standard, 100+ days
Variety names link to seed potatoes on Amazon. As an Amazon Associate we earn from qualifying purchases. These are the varieties named in the extension sources for this crop, not a paid placement — where a source recommended a variety for a specific reason, that reason is the note beside it.
Put it in a bed
The garden planner checks every square against this ledger as you place crops — if you drop potato next to something recorded as a bad neighbour, the square turns red and tells you why.
Records for the plants named above:
Same rotation group (nightshade) — don't follow one with another:
Potato companion planting questions
What should not be planted next to potato?
How far apart should potato be planted?
Does companion planting with potato actually work?
When should I plant potato?
Sources for this record
- Growing potatoes in home gardens, University of Minnesota Extension
- Home Garden Potatoes (C1011), University of Georgia Extension
- Potato, Home Vegetable Gardening, University of Illinois Extension
- Potato (Solanum tuberosum), University of Illinois Extension HortAnswers
- Potato Production, Penn State Extension
Record compiled 2026-07. Spot an error or a study we missed? Tell us and we'll correct the entry.