Turnip Companion Plants
Brassica rapa subsp. rapa · cabbage family family · rotation group: brassica
The best companion plants for turnip are Collards, Broccoli, Pea, Lettuce, and Onion. Avoid planting turnip near Radish, Other brassicas, Potato. Of the 10 pairings recorded here, 2 are supported by published research and 7 are traditional practice with no controlled evidence behind them.
What to plant with turnip
| Plant | Claimed benefit | Evidence | What the evidence actually shows |
|---|---|---|---|
| Broccoli | Turnip sown as an edge strip acts as a trap crop that keeps flea beetles off broccoli and other cole crops. | Research-backed | George, Port & Collier (Insects 10:286, 2019) found turnip rape borders took significantly more flea beetle feeding than the cauliflower they surrounded — a genuine trap effect — but simply placing the trap at the crop edge did not reliably reduce damage to the main crop; a 3-6 m bare-soil gap worked better, and the trap crop also raised overall beetle pressure in those plots. Benefit was clearest late in the season under high pest pressure. |
| Collards | A border or block of turnip planted near collards or cabbage pulls harlequin bug off the main crop. | Research-backed | Harlequin bug demonstrably prefers mustard, turnip, kale, rutabaga and Chinese cabbage over cabbage, collards, broccoli and radish (Sullivan & Brett 1974, reviewed by Wallingford et al.), and border rows of mustard cut harlequin bug injury in collard by roughly 50% without insecticide in Virginia field trials — but the replicated trap-crop trials used mustard, not turnip, separation distance changed the result fourfold, and an unmanaged trap crop becomes a nursery unless it is treated or destroyed. |
| Lettuce | Lettuce and turnip share a bed well because both are quick, shallow-rooted cool-season crops. | Traditional | A spacing and season-matching convenience only; no trial has measured a pest, disease, or yield effect from the combination. |
| Nasturtium | Nasturtium planted with turnips is said to pull aphids and caterpillars away from the crop. | Traditional | Nasturtium has real supporting data in other systems — reduced squash bug and cucumber beetle damage in cucurbits, and reduced cabbage looper and imported cabbageworm damage in broccoli — but no trial has tested it with turnip, so the extension to this crop is unverified. |
| Onion | Onions interplanted with turnips are said to mask the crop and deter brassica pests. | Traditional | UMN Extension reports research in which thyme, onion and nasturtium reduced cabbage looper and imported cabbageworm damage in broccoli, but the same page states there is little research supporting green onions as a flea beetle repellent and that some studies contradict it — and turnip was not the crop tested either way. |
| Pea | Peas are said to improve the soil for a following or neighboring turnip crop. | Traditional | Standard chart advice with no controlled evidence for turnip specifically; nitrogen fixed by peas is mostly exported in the seed and released only as residue decomposes, so any benefit is to the next crop, not the neighbor. |
| Marigold | Marigolds interplanted among turnips and other brassicas repel flea beetles. | Not supported | UMN Extension states directly that companion plants such as marigolds and green onions are listed for flea beetle control on gardening sites and even some extension websites, 'but there is little research to support this and some contradict it'; Illinois Extension likewise reports the marigold-as-beetle-deterrent claim tested and not supported. Marigold's genuinely evidenced use is as a solid-stand pre-plant cover crop against root-knot nematodes, not as a few interplanted flowers. |
What not to plant with turnip
| Plant | Claimed problem | Evidence | What the evidence actually shows |
|---|---|---|---|
| Other brassicas | Turnip should not be grown in ground that recently carried cabbage, broccoli, kale or mustard. | Traditional | Rotation guidance rather than an antagonism: UMN Extension lists clubroot, black rot and Alternaria as turnip diseases, and clubroot in particular persists in soil for years and builds up under continuous brassicas. Note this is a between-season concern and does not contradict the within-season trap-cropping benefit listed under companions. |
| Potato | Potatoes are said to do poorly when grown next to turnips. | Traditional | Repeated on garden charts with no measured mechanism; UMN Extension warns that published lists of antagonistic plants are frequently not accurate or research-backed, and no trial testing turnip against potato was found. |
| Radish | Turnips should not follow radishes (or other turnips) in the same ground. | Traditional | Illinois Extension states that root maggots are a problem in areas where radishes, turnips or rutabagas were grown the previous year. This is documented rotation guidance based on observed pest carryover, not a companion-planting trial, and it says nothing about growing the two side by side in one season. |
The honest verdict
Of everything gardeners recommend planting alongside turnip, 2 pairings have been tested properly: Collards, Broccoli. Those are the ones worth planning your bed around.
The remaining 4 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 — UMN Extension states directly that companion plants such as marigolds and green onions are listed for flea beetle control on gardening sites and even some extension websites, 'but there is little research to support this and some contradict it'; Illinois Extension likewise reports the marigold-as-beetle-deterrent claim tested and not supported. Marigold's genuinely evidenced use is as a solid-stand pre-plant cover crop against root-knot nematodes, not as a few interplanted flowers.
Every row above links to the publication it came from. See how we grade evidence.
Growing turnip: the numbers
| Sun | Full sun (6+ hours) |
|---|---|
| Water | Moderate |
| Spacing | 4 in apart · 15 in between rows · 9 per square foot |
| Mature size | about 15 in tall |
| Soil pH | 6–7 |
| Days to maturity | 40–75 days |
| Frost tolerance | Hardy — takes hard frost |
| Containers | Yes — 3 gallon minimum |
| Typical yield | 1 root, 2-3 in across, plus greens |
| Common pests | flea beetles, cabbage root maggot, harlequin bug, aphids, imported cabbageworm |
| Common diseases | clubroot, alternaria leaf spot, black rot, downy mildew |
When to plant turnip
Zone 6b shownDirect sow outdoors: Mar 13 – Mar 26 — 4 weeks before last frost
Expected harvest: Apr 22 – May 27 — 40–75 days from planting
Fall planting: Aug 25 – Sep 7 — 9 weeks before your first fall frost
Those dates are for zone 6b. Get your own dates by ZIP code →
Varieties worth knowing
seeds- Purple Top White Globe — The traditional American open-pollinated turnip; globe roots for storage, best pulled at 2-3 inches across before they turn woody.
- Hakurei — Early white F1 salad turnip; roots eaten raw and greens harvested too, the fastest type in the Johnny's range (35-54 day group).
- Scarlet Queen Red Stems — Red-skinned F1 salad turnip with crisp white flesh and spicy skin; grown for fresh eating rather than storage.
- Shogoin — Grown mainly for its greens rather than the root, per University of Illinois Extension's variety list.
Variety names link to seeds 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 turnip 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 (brassica) — don't follow one with another:
Turnip companion planting questions
What should not be planted next to turnip?
How far apart should turnip be planted?
Does companion planting with turnip actually work?
When should I plant turnip?
Sources for this record
- University of Minnesota Extension — Growing turnips and rutabagas in home gardens
- University of Illinois Extension — Turnip
- UC IPM — Cultural Tips for Growing Turnip
- Penn State Extension (York County Master Gardeners) — Vegetable Seed Planting Guide
- UMass Extension — Root Crops Growing Tips
Record compiled 2026-07. Spot an error or a study we missed? Tell us and we'll correct the entry.