Description
Caltha – Kingcup – Marsh Marigold –
There are about 10 species of rhizomatous, marshland or marginal aquatic perennials and herbaceous, moisture loving perennials, in this genus. They occur in temperate and cold region in both hemispheres. The leaves are generally heart or kidney shaped. Those grown as marginal water plants provide a display of cup shaped, yellow or white flowers in early spring, appearing from beneath the melting snow. They are carried in terminal or axillary corymbs before the dense clumps of foliage are produced, a second flush of flowers is often produced in late summer. Although they are best grown at the water’s edge, several will thrive in a mixed or herbaceous border if soil is kept moist.
Grow in an open site in rich, boggy soil in full sun at the water’s edge, marsh marigolds will tolerate root restriction in aquatic containers. Divide in late summer or very early spring.
Prone to powdery mildew and rust.
Caltha palustris var. alba – Caltha palustris ‘Alba’ – This compact, deciduous or semi evergreen, variable, marginal aquatic perennial grows 9″ tall and 12″ wide. From decumbent rhizomes sprout kidney shaped, toothed, dark green leaves, 1 ½-4″ long. In early spring it bears stems 12-18″ tall, solitary white flowers with yellow stamen, 1 ½” across, often before leaves appear. May grow in water to 9″ deep for short periods, but prefers very shallow water or bog conditions.
Zones 3-8
