Yellow rattle

Rhinanthus minor

Slender annual semi-parasite of grass roots, with hooded yellow flowers and inflated seed capsules. The single most useful plant for establishing wildflower meadows.

Hardiness ratings

Yellow rattle hardiness across the four zone systems
SystemRatingTemperature rangeHow to read it
USDA hardiness zone Zone 3–8 −40 °C to −6.7 °C Zones where it can be grown as an annual — not a frost-tolerance rating
RHS hardiness rating H7 down to −20 °C Plant needs at least this level of cold tolerance
Canadian plant hardiness zone Zone 3–8 −34 °C to −1 °C Zones where it can be grown as an annual — not a frost-tolerance rating
Australian (ANBG) zone Zone 1–5 −15 °C to 10 °C Zones where it can be grown as an annual — not a frost-tolerance rating

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

Growing notes

  • Semi-parasitic on grass roots — weakens vigorous grasses and lets slower wildflowers establish, the cornerstone of any meadow conversion
  • Flowers in June, then ripens rattling seed pods that give the plant its name
  • Sow fresh seed in autumn into mown, raked grass — needs winter chilling to germinate

Categories

Related plants

Cross-check Yellow rattle against your zones

Reference

Yellow rattle on Wikipedia