Arugula Companion Plants
Eruca vesicaria subsp. sativa · mustard family family · rotation group: brassica
The best companion plants for arugula are Sweet alyssum, White clover (undersown living mulch), Mustard (border trap crop), Lettuce, and Nasturtium. Avoid planting arugula near Strawberry, Other brassicas, Tomato. Of the 11 pairings recorded here, 3 are supported by published research and 7 are traditional practice with no controlled evidence behind them.
What to plant with arugula
| Plant | Claimed benefit | Evidence | What the evidence actually shows |
|---|---|---|---|
| Mustard (border trap crop) | A border row of mustard or rapeseed pulls harlequin bugs away from the salad greens. | Research-backed | Choice tests and field trials confirm harlequin bug strongly prefers mustard over collard, and mustard borders cut feeding damage. Important caveat for this crop: the same study found arugula itself was among the most attractive hosts, so a mustard border protects arugula less reliably than it protects collards. |
| Sweet alyssum | Flowering alyssum planted beside brassica greens feeds hoverflies and parasitoid wasps that suppress aphids and caterpillars. | Research-backed | Replicated organic-cabbage trials found insectary alyssum significantly raised parasitism of brassica caterpillars and the abundance of predatory lady beetle eggs and larvae; the measured effect is on natural-enemy numbers and parasitism rate, and trials used flowering strips rather than a few scattered plants. |
| White clover (undersown living mulch) | Undersowing arugula and other brassicas with low-growing living clover reduces colonisation by cabbage root fly and aphids. | Research-backed | Cage and field experiments consistently reduced cabbage root fly egg-laying in clover-undersown brassicas, but the same work showed dried brown clover gave no protection while living green clover did — so the mechanism is disrupted host-plant finding over a green background, not repellency. Clover also competes for water and nitrogen and will cut leaf yield if established too early. |
| Bush bean | Nitrogen-fixing beans are said to feed neighbouring leafy greens. | Traditional | Most nitrogen fixed by a bean crop stays in the plant until it dies and decomposes, so a same-season fertility transfer to adjacent arugula is unlikely. The pairing is defensible as a rotation and space-use choice, not as in-season feeding. |
| Dill | Dill flowers feed the small parasitoid wasps and hoverflies that attack brassica aphids and caterpillars. | Traditional | Umbel flowers are a well-documented nectar source and insectary strips generally do raise natural-enemy numbers, but the tested species in brassica systems are sweet alyssum and buckwheat, not dill. Note also that extension companion charts commonly list dill as a plant to keep away from cabbage-family crops — the two traditions contradict each other and neither is backed by trial data. |
| Lettuce | Interplanted with lettuce for a mixed salad bed; the two are said to share space without competing. | Traditional | No controlled trial supports a pest or growth benefit. The real advantage is practical: matched cool-season timing, similar shallow rooting and similar cut-and-come-again harvest, so one bed can be managed as a unit. |
| Nasturtium | Grown as a sacrificial trap plant to draw aphids and cabbage white butterflies off the greens. | Traditional | Nasturtium is a real host for cabbage whites and aphids, so the mechanism is plausible, but replicated trap-crop trials in brassica greens use mustard, kale and collards — not nasturtium. Untested at garden scale. |
| Thyme | Aromatic thyme is said to repel cabbage moths and flea beetles with its scent. | Not supported | This one has actually been tested. When aromatic plants were compared against non-aromatic green plants around brassicas, the aromatic species were no more effective: any living green ground cover reduced egg-laying, and dried brown plant material did not. The reduction comes from disrupted host-finding over a green background, not from thyme's volatiles, so the scent-repellency claim as usually stated is not supported. |
What not to plant with arugula
| Plant | Claimed problem | Evidence | What the evidence actually shows |
|---|---|---|---|
| Other brassicas | Crowding arugula in with other cabbage-family crops concentrates shared pests and soil-borne diseases. | Traditional | The underlying disease logic is sound and standard: extension advises rotating brassicas out of a bed for several years because clubroot, black rot and Alternaria persist in soil and debris. The specific harm from one season of side-by-side planting is inferred from that rotation advice rather than measured. |
| Strawberry | Extension companion charts list strawberries among the plants not to grow near cabbage-family crops. | Traditional | Repeated across extension companion charts with no supporting trial. The chart source itself states companion planting 'is not an exact science' and that results vary by area; no measured yield or pest effect for arugula and strawberry exists. |
| Tomato | Tomatoes are listed as a plant to avoid near cabbage-family crops, usually explained as heavy-feeder nutrient competition. | Traditional | No trial supports it. The nutrient-competition explanation is weak for arugula specifically — a 30-50 day baby-leaf crop removes very little from the soil. The practical conflict is real but mundane: a full-size tomato shades and heats the bed, and arugula bolts in heat. |
The honest verdict
Of everything gardeners recommend planting alongside arugula, 3 pairings have been tested properly: Sweet alyssum, White clover (undersown living mulch), Mustard (border trap crop). 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: Thyme — This one has actually been tested. When aromatic plants were compared against non-aromatic green plants around brassicas, the aromatic species were no more effective: any living green ground cover reduced egg-laying, and dried brown plant material did not. The reduction comes from disrupted host-finding over a green background, not from thyme's volatiles, so the scent-repellency claim as usually stated is not supported.
Every row above links to the publication it came from. See how we grade evidence.
Growing arugula: the numbers
| Sun | Full sun (6+ hours) |
|---|---|
| Water | Moderate |
| Spacing | 6 in apart · 12 in between rows · 4 per square foot |
| Mature size | about 18 in tall |
| Soil pH | 6–7 |
| Days to maturity | 30–50 days |
| Frost tolerance | Hardy — takes hard frost |
| Containers | Yes — 3 gallon minimum |
| Typical yield | 2-3 cut-and-come-again harvests per plant |
| Common pests | flea beetle, aphid, cabbage looper, imported cabbageworm, leaf miner, slug |
| Common diseases | bacterial blight, black rot, root rot |
When to plant arugula
Zone 6b shownDirect sow outdoors: Mar 13 – Mar 26 — 4 weeks before last frost
Expected harvest: Apr 12 – May 2 — 30–50 days from planting
Fall planting: Sep 15 – Sep 28 — 6 weeks before your first fall frost
Those dates are for zone 6b. Get your own dates by ZIP code →
Varieties worth knowing
seeds- Roquette — Standard common arugula listed by UC Marin Master Gardeners; fast salad type ready in about 5-6 weeks.
- Astro — Recommended by UC Marin Master Gardeners; smoother, less-lobed leaf and a milder flavour than wild types.
- Dragon's Tongue — Recommended by UC Marin Master Gardeners; deeply lobed leaf with red-purple veining, used for colour in salad mixes.
- Wasabi arugula — Recommended by UC Marin Master Gardeners; notably pungent, used as a garnish green rather than a bulk salad leaf.
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 arugula 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:
Arugula companion planting questions
What should not be planted next to arugula?
How far apart should arugula be planted?
Does companion planting with arugula actually work?
When should I plant arugula?
Sources for this record
- UC Marin Master Gardeners — Arugula
- University of Wisconsin-Madison Division of Extension — Arugula, Eruca sativa
- Penn State Extension — Production Limitations of Arugula in the Northeast
- Illinois Extension Good Growing — Arugula: A New Trendy Green from the Old World
- NC State Extension Plant Toolbox — Eruca vesicaria
Record compiled 2026-07. Spot an error or a study we missed? Tell us and we'll correct the entry.