Caltha leptosepala (white-flowered marsh marigold) — Perennial

Overview

Caltha leptosepala is a perennial in the genus Caltha, part of the Ranunculaceae family. It typically grows around 0.3 m tall. Caltha leptosepala grows best in full sun, and tolerates most soils. Its UK hardiness is rated H7. It is native to W N America.

About the genus

Caltha is a genus of rhizomatous perennial flowering plants in the family Ranunculaceae, to which ten species have been assigned. They occur in moist environments in temperate and cold regions of both the Northern and Southern Hemispheres. Their leaves are generally heart-shaped or kidney-shaped, or are characteristically diplophyllous.

Wikipedia contributors, "Caltha", CC BY-SA 4.0 — Caltha

In the garden

Caltha leptosepala is a perennial member of the Ranunculaceae native to western North America. In cultivation it is valued for its early-season white blooms, which appear in the UK from March to May, and for its modest height of around 0.3 m. Plant it where soil stays wet and receives full sun; the species tolerates sandy, loamy or clay soils so long as moisture is constant. Its UK hardiness rating is H7 (fully hardy), and the USDA hardiness range 3–7 indicates it withstands a wide span of winter conditions in temperate gardens. Use Caltha leptosepala at the margins of ponds, in bog gardens or in any damp hollow that remains saturated through spring. Give it a sunny aspect and avoid drying-out between the roots; even on heavier clay it will persist if the site stays wet. Expect its compact spread and white spring flowers at about 0.3 m high to define a neat early-spring edge in wet garden situations.

Growing conditions

Best soil and position for Caltha

Sunlight: Full sun
Soil type: Sandy, Loamy, Clay
Soil moisture: Wet
UK hardiness: H7

Plant details

Caltha leptosepala size, habit and characteristics

Plant type: Perennial
Height: 0.3 m
Native to: W N America

Care notes

Pruning and caring for Caltha leptosepala

Propagation: Division, Seed

Frequently asked questions

Where is the best place to plant Caltha leptosepala?

Caltha leptosepala prefers full sun.

What soil does Caltha leptosepala need?

Caltha leptosepala is adaptable and grows happily in most soil types, including sandy, loamy and clay. Aim for soil that stays wet.

How big does Caltha leptosepala grow?

Caltha leptosepala reaches a height of 0.3 m.

Is Caltha leptosepala hardy in the UK?

Caltha leptosepala has an RHS hardiness rating of H7, meaning it is fully hardy throughout the UK, tolerating temperatures below -20°C.