Spearmint Companion Plants
Mentha spicata · mint family family · rotation group: other
The best companion plants for spearmint are Pea and Pea. Avoid planting spearmint near Chamomile. Of the 6 pairings recorded here, 0 are supported by published research and 2 are traditional practice with no controlled evidence behind them.
What to plant with spearmint
| Plant | Claimed benefit | Evidence | What the evidence actually shows |
|---|---|---|---|
| Pea | Peas are said to benefit from mint grown at the bed edge. | Traditional | Common in companion charts; no controlled evidence, and mint should be contained regardless. |
| Cabbage | Mint's aroma repels cabbage moths and flea beetles. | Not supported | WSU Extension is explicit that field research has not borne this out for mint or any other aromatic species, because the volatile compounds dissipate too fast in an open garden. |
| Carrot | Mint is said to mask the scent that guides carrot rust fly. | Not supported | Scent-masking by aromatic herbs is the specific belief WSU Extension reports field research does not support. |
| Kale | Mint is planted near kale to reduce aphid colonisation. | Not supported | No repellent effect demonstrated in the field; sweet alyssum is the evidence-backed choice for aphid suppression. |
| Tomato | Mint planted nearby deters aphids and improves tomato vigour. | Not supported | Same aromatic-repellency failure; aromatic plants may work in closed greenhouses but not in open gardens. |
What not to plant with spearmint
| Plant | Claimed problem | Evidence | What the evidence actually shows |
|---|---|---|---|
| Chamomile | Low-growing neighbours are smothered by mint runners. | Traditional | A direct consequence of documented rhizomatous spread rather than a chemical antagonism.
Source: Herbs, Clemson HGIC |
The honest verdict
None of the companion pairings commonly recommended for spearmint 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 1 pairing on this page is 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: Cabbage — WSU Extension is explicit that field research has not borne this out for mint or any other aromatic species, because the volatile compounds dissipate too fast in an open garden.; Tomato — Same aromatic-repellency failure; aromatic plants may work in closed greenhouses but not in open gardens.; Carrot — Scent-masking by aromatic herbs is the specific belief WSU Extension reports field research does not support.; Kale — No repellent effect demonstrated in the field; sweet alyssum is the evidence-backed choice for aphid suppression.
Every row above links to the publication it came from. See how we grade evidence.
Other recorded effects
2Effects that aren't about a neighbouring plant — what spearmint does for (or to) the garden around it, and the caveats attached to the popular versions of those claims.
| Effect | The claim | Evidence | What the evidence actually shows |
|---|---|---|---|
| Pollinators | Mint allowed to flower is a heavy nectar source for bees and hoverflies. | Traditional | Flowering mint is genuinely attractive to pollinators, but this is observational rather than a controlled crop-benefit trial. |
| Any In-Ground Neighbour | Mint overruns whatever is planted beside it. | Research-backed | Illinois Extension states mints aggressively spread by underground rhizomes and become invasive in the garden; this is the single most practical fact about growing mint. |
Growing spearmint: the numbers
| Sun | Partial sun (3–6 hours) |
|---|---|
| Water | High — keep evenly moist |
| Spacing | 15 in apart · 18 in between rows · 1 per square foot |
| Mature size | about 18 in tall |
| Soil pH | 6–8 |
| Days to maturity | 60–90 days |
| Frost tolerance | Hardy — takes hard frost |
| Containers | Yes — 2 gallon minimum |
| Hardiness zones | 4–9 (perennial) |
| Common pests | spider mites, aphids, flea beetles |
| Common diseases | mint rust, leaf spot, verticillium wilt |
When to plant spearmint
Zone 6b shownStart seeds indoors: Feb 13 – Feb 27 — 6–8 weeks before your last frost
Transplant outdoors: Apr 10 – Apr 23 — around your last frost date
Expected harvest: Jun 9 – Jul 9 — 60–90 days from planting
Those dates are for zone 6b. Get your own dates by ZIP code →
Varieties worth knowing
seeds- Kentucky Colonel — superior large foliage; the standard spearmint selection
- Mentha x piperita (peppermint) — higher menthol; sterile hybrid, propagate by division
- Mentha suaveolens (apple mint) — fuzzy leaves, milder flavour
- Mentha x piperita f. citrata (chocolate mint) — popular dessert and tea selection
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 spearmint 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 (other) — don't follow one with another:
Spearmint companion planting questions
What should not be planted next to spearmint?
How far apart should spearmint be planted?
Does companion planting with spearmint actually work?
When should I plant spearmint?
Sources for this record
- Mentha spicata, NC State Extension Gardener Plant Toolbox
- Mints...Friend or Foe?, Illinois Extension
- Herbs: Mint, Illinois Extension
- CMG GardenNotes #731, Herb Gardening, Colorado State University Extension
- Growing herbs in home gardens, University of Minnesota Extension
Record compiled 2026-07. Spot an error or a study we missed? Tell us and we'll correct the entry.