Marsh Marigold

Herbaceous

Marsh Marigold

Caltha palustris

Also known as: Kingcup, Cowslip (European common name; not the primrose)

HerbaceousAquatic Ranunculaceae OrnamentalWildlife AttractorPollinatorWater Retention
Hardiness Zone
3-7
Ideal Temp
40–72°F
Survives Down To
-40°F
Life Cycle
Perennial

Marsh marigold (Caltha palustris) is a glossy-leaved, buttercup-family perennial of cold seeps, pond margins, and slow streams. In spring it throws up hollow stems and bright yellow, shiny-petaled flowers above kidney-shaped leaves; clumps typically stay under about 18 inches tall but can spread into broad colonies where soil stays wet. It is a temperate icon of spring wetlands, not a tropical workhorse. subtropical and tropical Americas: Treat it as a niche or seasonal experiment in shaded, constantly moist microsites at elevation or in the coolest pockets you can engineer—humid heat and dry-down periods are what send it to the compost confessional. ☀️💧 Sun and Water Requirements: - Part sun to light shade in hot climates; cooler regions tolerate more sun if roots never dry. - True bog moisture: roots in muck or shallow water; no “well-drained” fantasy—this plant wants the squelch. ✂️ Propagation: - Division in late winter or immediately after flowering while soil is wet; reset divisions at the water’s edge. - Seed: sow fresh seed on wet peat/muck; many populations need cold-moist stratification—start in trays outdoors through winter in suitable climates. 🌾 Harvest / Best Use Timing: - All parts are toxic raw; do not forage like salad unless you enjoy ER fanfiction. - Enjoy as an early pollinator pulse and wetland stabilizer; cut back spent stems after seed drop if you manage aesthetics around a pond edge.

Good Neighbors
  • Cattail — shares the same soggy real estate; tall cattails define the deep-water side while marsh marigold carpets the shallows, reducing bare-muck erosion.
  • Blue Flag Iris — staggered bloom and contrasting foliage structure keep the margin visually legible while roots interlace to armor soft banks.
  • Softstem Bulrush — vertical stems break wind fetch on small ponds; marsh marigold fills the transition zone between open water and upland rush tussocks.
Known Threats — Organic Solutions Only
Aphids
Aphidoidea
Slugs
Gastropoda