French marigold

Tagetes patula

Compact pungent-leaved annual with small orange, yellow or mahogany flowers. The classic vegetable-bed companion plant for nematode suppression.

Hardiness ratings

French marigold hardiness across the four zone systems
SystemRatingTemperature rangeHow to read it
USDA hardiness zone Zone 2–11 −45.6 °C to 10 °C Zones where it can be grown as an annual — not a frost-tolerance rating
RHS hardiness rating H2 1 °C to 5 °C Plant needs at least this level of cold tolerance
Canadian plant hardiness zone Zone 2–9 −40 °C and warmer Zones where it can be grown as an annual — not a frost-tolerance rating
Australian (ANBG) zone Zone 1–7 −15 °C and warmer Zones where it can be grown as an annual — not a frost-tolerance rating

As a tender annual, French marigold doesn't overwinter — the zone range shows where the growing season supports it. See the RHS rating for its actual cold tolerance.

Growing notes

  • Root exudates suppress root-knot nematodes in soil — effect is scientifically verified but requires a full season of growth in the affected ground
  • Forage for hoverflies and other small pollinators
  • Pungent foliage scent is strongly disliked by some flying pests (whitefly, aphids) although the effect is unreliable
  • Distinct from pot marigold (Calendula) despite the shared common name

Pet caution: French marigold is listed as potentially harmful to cats and/or dogs. Keep pets from grazing on it, and contact a vet if you suspect your animal has eaten some.

Categories

Related plants

Cross-check French marigold against your zones

Reference

French marigold on Wikipedia