Marsh marigold (Kingcup)

Caltha palustris

Native pond-margin perennial with large glossy buttercup-yellow flowers in earliest spring above mounds of round dark green leaves.

Hardiness ratings

Marsh marigold (Kingcup) hardiness across the four zone systems
SystemRatingTemperature rangeHow to read it
USDA hardiness zone Zone 3–7 −40 °C to −12.2 °C Plant tolerates down to this zone
RHS hardiness rating H7 down to −20 °C Plant needs at least this level of cold tolerance
Canadian plant hardiness zone Zone 3–7 −34 °C to −7 °C Plant tolerates down to this zone
Australian (ANBG) zone Zone 1–5 −15 °C to 10 °C Plant tolerates down to this zone

Growing notes

  • Among the very first wetland flowers of spring — a key seasonal marker
  • Important early forage for emerging bees and hoverflies
  • Thrives in pond margins, bog gardens and seasonally wet ground
  • All parts mildly toxic (irritant sap) — do not eat raw

Pet caution: Marsh marigold (Kingcup) 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 Marsh marigold (Kingcup) against your zones

Reference

Marsh marigold (Kingcup) on Wikipedia