Overview

Megacarpaea polyandra is a garden plant in the genus Megacarpaea, part of the Brassicaceae family. It typically grows around 1.8 m tall. Megacarpaea polyandra grows best in full sun, and tolerates sandy and loamy soils. Its UK hardiness is rated H6.

About

Megacarpaea polyandra is a tall member of the Brassicaceae, reaching around 1.8 m. It flowers from June to August. It prefers full sun and establishes on sandy or loamy soils that are moist but well drained. It carries a UK hardiness rating of H6 (very hardy) and corresponds to USDA zones 6–9.

About the genus

Megacarpaea is a genus of flowering plants belonging to the family Brassicaceae.

In the garden

Megacarpaea polyandra sits within the mustard family, growing to roughly 1.8 m and producing its flowering display between June and August. The botanical identity and stature make it a clearly vertical presence where room allows. Its cultural needs are straightforward: choose a sunny position and a free-draining substrate. Sandy or loamy soils that retain moisture without becoming waterlogged suit it best; avoid heavy clay that stays wet. Site selection should favour full sun and good air movement at soil level. The H6 hardiness rating means it is very hardy in typical UK gardens, tolerating cold winters in most areas, and the USDA 6–9 range indicates similar resilience where those maps are used. Planting on a slight rise or in a border with gritty material will help maintain the moist but well-drained conditions it prefers. Use Megacarpaea polyandra where height is required: as a backdrop in tall sunny borders or where a vertical element is needed without dense shade. Allow clear root drainage and enough vertical space for its 1.8 m habit, and avoid locations where winter-saturated soil could collect at the crown.

Growing conditions

Best soil and position for Megacarpaea

Sunlight

Full sun

Soil type

Sandy, Loamy

Soil moisture

Moist but well-drained

UK hardiness

H6

Plant details

Megacarpaea polyandra size, habit and characteristics

Height

1.8 m

Frequently asked questions