Rheum flowers

Herbaceous rhizomatous perennials grown for their large decorative leaves and attractive flower spikes. Thrives in moist ground.

Family: Polygonaceae
Botanical Name: Rheum (ray-um)
Common Names: Ornamental rhubarb

Foliage: Deciduous, large, simple or palmately lobed green leaves.

Flowers: Tall plumes of tiny flowers on stout stems.

Flowering Period: Summer.

Soil: Moist but not waterlogged, fertile soil (clay or loam). Acid or neutral pH.

Conditions: Full sun or partial shade. Plant in any aspect.

Habit: Upright.

Type: Rhizomatous herbaceous perennial.

Origin: Siberia, Himalayas and eastern Asia.

Hardiness: Hardy in the UK.

Toxicity: Can cause stomach upset if ingested. Wear gloves and wash hands after handling.

Planting and Growing Rheum

Plant at any time in dormant season. Thrives in heavy, moisture-retentive, humus rich soil, in an open sunny site.

Provide this plant plenty of room to spread.

A popular choice for the poolside or a damp border.

Taking Care of Rheum

Water copiously in dry spells. Mulch in spring to retain moisture.

Pruning Rheum

Cut back dead foliage in autumn.

Pests and Diseases

Can be attacked by black fly. Susceptible to rhubarb crown rot.

Propagating Rheum

Sow seed in spring. Prick out and pot on until large enough to plant out.

Increase cultivars by division in autumn, once they have developed several strong crowns.

Popular Varieties of Rheum

Rheum alexandrae produces large oval veined leaves topped by 1ft (30cm) flower spikes, in June-July. Height and spread to 3ft (90cm).

Rheum palmatum (China) has large lobed green leaves with strong rhubarb-like stalks. Topped with tall spires of tiny red flowers in June-July. Height up 6ft (2m), spread to 4ft (1.2m). Attractive cultivars include 'Atrosanguineum' and 'Bowles Crimson' both with red flushed foliage and red flowers.