Overview

Caulophyllum thalictroides is a perennial herb in the genus Caulophyllum, part of the Berberidaceae family. It typically grows around 0.5 m tall. Caulophyllum thalictroides grows best in full shade, and tolerates sandy and loamy soils. Its UK hardiness is rated H6. It is native to E N America.

About

Caulophyllum thalictroides is a perennial herb from eastern North America that reaches about 0.5 m in height. It favours deep shade and grows in moist, sandy or loamy, well-drained soils. Flowering occurs in April to May with small yellow blooms and the foliage is blue-green. The plant is toxic and should be handled with care.

Wikipedia contributors, CC BY-SA 4.0 — Caulophyllum thalictroides

About the genus

Caulophyllum is a small genus of perennial herbs belonging to the family Berberidaceae and closely related to the Eurasian genera Leontice and Gymnospermium. It is native to eastern Asia and eastern North America.

In the garden

Caulophyllum thalictroides (Blue Cahosh) is a shade-adapted perennial herb in the Berberidaceae, native to eastern North America. Plants produce single upright shoots to around 0.5 m and carry blue-green leaves; flowering in the UK occurs in April to May. The species suits the quieter end of the season when early shade perennials are coming into growth. For cultivation choose a permanently shady spot with soil that is moist but well-drained; the plant tolerates sandy or loamy substrates. It is classed H6 for the UK, which translates as very hardy in most British gardens, and corresponds to USDA zones 6–9. Position crowns where they will not dry out in summer or be waterlogged in winter and avoid exposed, baking sites. Use Blue Cahosh in a woodland or shaded border, beneath deciduous trees, or in a naturalistic shade bed where its modest 0.5 m height will sit beneath taller spring bulbs and shrubs. Include a note of caution: the species is toxic, so avoid planting where children or pets might handle it. Allow roughly 0.5 m between crowns when planting so each clump has space to expand.

Growing conditions

Best soil and position for Caulophyllum

Sunlight

Full shade

Soil type

Sandy, Loamy

Soil moisture

Moist but well-drained

UK hardiness

H6

Plant details

Caulophyllum thalictroides size, habit and characteristics

Plant type

Perennial herb

Height

0.5 m

Native to

E N America

Toxicity

Toxic

Care notes

Pruning and caring for Caulophyllum thalictroides

Propagation

Seed, division

Frequently asked questions