Overview

Rheum alexandrae is a perennial in the genus Rheum, part of the Polygonaceae family. Rheum alexandrae grows best in partial shade, and tolerates most soils and acidic to neutral pH. Its UK hardiness is rated H5. Suggested uses include ornamental, borders and water gardens. It is native to SW China.

About

Rheum alexandrae is a perennial in the knotweed family (Polygonaceae) valued for ornamental use in borders and water gardens. It originates from south-west China and flowers in the UK from June to July. Planting and handling require care because all parts are harmful if eaten; wear gloves and protective equipment when working with it.

About the genus

Rheum is a genus of about 60 herbaceous perennial plants in the family Polygonaceae. Species are native to eastern Europe, southern and eastern temperate Asia, with a few reaching into northern tropical Asia. Rheum species are cultivated in Europe, Asia, and North America.

Wikipedia contributors, "Rheum (plant)", CC BY-SA 4.0 — Rheum (plant)

In the garden

Rheum alexandrae is a perennial member of Polygonaceae native to south-west China, grown in the UK for its ornamental presence in damp situations. It flowers from June to July and is most often used at the edge of ponds, in moisture-retentive borders or other sheltered sites where partial shade protects it from strong sun. Position plants where they receive partial shade to shade and where soil remains moist and rich; acidic to neutral conditions suit it best. The plant prefers a sheltered aspect and will not do well in hot, exposed positions. In the UK it has an H5 rating, meaning it is classed as hardy across typical garden conditions but benefits from protection from drying winds and prolonged drought. Avoid planting where soils dry out or where full sun will scorch leaf tissue. Because all parts are harmful if eaten, handle with care and wear gloves and other protective equipment when planting, dividing or pruning, and keep pets away from the planting area; for pet-specific advice consult the HTA guide to potentially harmful plants. Use Rheum alexandrae as a water-side specimen or a moisture-loving border accent where its seasonal flowering can be seen from paths and seating areas.

Growing conditions

Best soil and position for Rheum

Sunlight

Partial shade

Soil type

Moist, rich, well-drained soil

Soil pH

Acidic to neutral

Soil moisture

Moist

Aspect

Sheltered

Exposure

Partial shade to shade

UK hardiness

H5

Plant details

Rheum alexandrae size, habit and characteristics

Plant type

Perennial

Suggested uses

Ornamental, borders, water gardens

Native to

SW China

Toxicity

Harmful if eaten. Wear gloves and other protective equipment when handling Pets: Harmful if eaten - for further information and contact numbers regarding pets, see the HTA guide to potentially harmful plants

Care notes

Pruning and caring for Rheum alexandrae

Cultivation

Prefers sheltered, damp conditions; avoid dry or exposed sites; mulch in winter

Pruning

Remove dead flower stems after flowering

Propagation

Division in spring or autumn

Frequently asked questions