Record — updated 2026-07

Calendula / Pot Marigold Companion Plants

Entry No. 052

Calendula officinalis · aster family family · rotation group: other

The best companion plants for calendula / pot marigold are Lettuce, Cabbage and Kale, Tomato and Tomato. Avoid planting calendula / pot marigold near Powdery Mildew Susceptible Neighbours. Of the 4 pairings recorded here, 0 are supported by published research and 4 are traditional practice with no controlled evidence behind them.

Research-backed tested in controlled research Traditional long practice, untested Not supported tested and not supported

What to plant with calendula / pot marigold

Companion plants for calendula / pot marigold — 0 research-backed, 3 traditional
Plant Claimed benefit Evidence What the evidence actually shows
Cabbage and Kale Calendula interplanted with brassicas reduces aphid damage. Traditional Plausible as a trap crop but untested; note calendula also hosts aphids, so it can seed the bed if left unmanaged.
Lettuce Calendula shares lettuce's cool-season timing and adds floral resources to the bed. Traditional Good cultural fit since both tolerate light frost; the pest benefit is unverified, and sweet alyssum has far better evidence in lettuce.
Tomato Calendula is a traditional tomato-bed flower said to deter pests. Traditional No controlled evidence; the marigold whitefly work applies to Tagetes patula, not to Calendula, which is a different genus entirely.

What not to plant with calendula / pot marigold

Plants to keep away from calendula / pot marigold
Plant Claimed problem Evidence What the evidence actually shows
Powdery Mildew Susceptible Neighbours Calendula is disease-free in the vegetable garden. Traditional Calendula is prone to powdery mildew and cucumber mosaic virus and can act as a reservoir beside susceptible crops.

The honest verdict

None of the companion pairings commonly recommended for calendula / pot marigold 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 3 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.

Every row above links to the publication it came from. See how we grade evidence.

Other recorded effects

4

Effects that aren't about a neighbouring plant — what calendula / pot marigold does for (or to) the garden around it, and the caveats attached to the popular versions of those claims.

Recorded effects and caveats — Calendula / Pot Marigold
Effect The claim Evidence What the evidence actually shows
Aphids (as a trap crop) Calendula draws aphids and whiteflies away from nearby vegetables. Traditional Calendula is a documented host for aphids and whiteflies, which is the mechanism a trap crop needs, but no controlled trial has measured protection of a neighbouring crop.
Pollinators and Predators Long-blooming open flowers feed hoverflies, lady beetles and pollinators. Traditional Open composite flowers are accessible to short-tongued beneficials; calendula itself was not among the plants in the controlled nectar trials.
Cut Flower and Edible Beds Calendula petals are edible and used fresh or dried as a dye and garnish. Research-backed Edibility and dye use are documented by NC State Extension; petals have a slightly bitter, tangy, peppery flavour.
Substituting Calendula for French Marigold Pot marigold works like French marigold for nematode control. Not supported A naming trap. The nematode-suppression research is specific to Tagetes, especially Tagetes patula; Calendula officinalis is an unrelated genus and carries none of that evidence.

Growing calendula / pot marigold: the numbers

Field data — Calendula / Pot Marigold
SunFull sun (6+ hours)
WaterModerate
Spacing12 in apart · 18 in between rows · 4 per square foot
Mature sizeabout 18 in tall
Soil pH6–7.5
Days to maturity50–60 days
Frost toleranceHalf-hardy — takes a light frost
ContainersYes — 2 gallon minimum
Common pestsaphids, whiteflies, slugs, snails
Common diseasespowdery mildew, cucumber mosaic virus

When to plant calendula / pot marigold

Zone 6b shown
J
F
M
A
M
J
J
A
S
O
N
D
Start indoors Sow / transplant outdoors Harvest

Start seeds indoors: Feb 13 – Feb 27 — 6–8 weeks before your last frost

Transplant outdoors: Mar 27 – Apr 9 — 2 weeks before last frost

Direct sow outdoors: Mar 27 – Apr 9 — 2 weeks before last frost

Expected harvest: May 16 – May 26 — 50–60 days from planting

Fall planting: Sep 1 – Sep 14 — 8 weeks before your first fall frost

Those dates are for zone 6b. Get your own dates by ZIP code →

Varieties worth knowing

seeds

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 calendula / pot marigold 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:

Calendula / Pot Marigold companion planting questions

What should not be planted next to calendula / pot marigold?
Powdery Mildew Susceptible Neighbours. Calendula is disease-free in the vegetable garden. Calendula is prone to powdery mildew and cucumber mosaic virus and can act as a reservoir beside susceptible crops.
How far apart should calendula / pot marigold be planted?
Space calendula / pot marigold about 12 inches apart in the row, with 18 inches between rows. In a square-foot bed that works out to 4 plants per square foot.
Does companion planting with calendula / pot marigold actually work?
Partly. None of the pairings we found for calendula / pot marigold have been confirmed in controlled trials. The rest are traditional practice: plausible, harmless to try, but untested. Treat the folklore as a starting point rather than a rule, and read what the evidence says about companion planting.
When should I plant calendula / pot marigold?
Start seed indoors 6–8 weeks before your last frost. Transplant outdoors 2 weeks before last frost. In zone 6b that means roughly Mar 27 – Apr 9. Get exact dates for your ZIP code →

Sources for this record

Record compiled 2026-07. Spot an error or a study we missed? Tell us and we'll correct the entry.