Cardamine amara
large bittercress
Overview
Cardamine amara is a perennial of wet ground 8-24 inches (20-60 cm) tall, with angular, leafy stems that sometimes root where they touch damp soil. The leaves are pinnately divided into several pairs of toothed leaflets and a larger end leaflet, fresh green and slightly fleshy. White four-petalled flowers about 0.5 inch (12 mm) across are carried in loose clusters from April to June, each with violet to purple anthers that stand out against the white petals. It grows along streamsides, in wet woodland, flushes, and fen, on ground that stays wet through the year. The slender seed pods stand erect on spreading stalks and shoot out their seeds when ripe. The violet anthers separate it from cuckooflower, Cardamine pratensis, which has pale lilac petals and yellow anthers.
Native Range
Native across much of Europe and into western Asia, growing along streams, in wet woodland, and in fens. In Britain it is most frequent in the north and east on wet, base-rich to neutral ground.Suggested Uses
Grown along stream and pond margins, in bog gardens, and in damp, shaded borders for spring flower. The peppery young leaves are edible, used like watercress in small amounts. The early flowers draw bees and hoverflies.How to Identify
Appearance
Size & Dimensions
Height8" - 2'
Width/Spread1' - 1'6"
Bloom Information
White flowers with violet anthers open from April to June. They are visited by early bees and hoverflies, and ripen into slender erect pods that split open to scatter the seeds.
Detailed Descriptions
Flower Description
White with violet anthersFoliage Description
Fresh greenGrowing Conditions
Sun Requirements
Requires 3-8 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Cardamine amara grows in part shade to full sun on wet, fertile, neutral to base-rich soil at a soil pH of about 6.0-7.5. It needs ground that stays moist to wet year-round, such as streamsides and pond margins, and it tolerates shallow flowing water. The leafy stems can root where they rest on damp ground, spreading the plant into loose patches. Hardy to about USDA zone 5, it withstands hard frost and dies back over winter. It tolerates light shade but flowers more freely with some sun. It self-seeds along wet ground where conditions suit.Pruning
Cardamine amara needs little pruning. Faded flower stems can be cut back to limit self-seeding, and old foliage can be cleared in late autumn or early spring as new growth appears.Container Growing
✓ Suitable for container growing
Minimum container size: 2 gallons