Symphytum flowers

Tough clump-forming, spreading perennials with coarse green leaves and pretty tubular flowers. The leaves are useful as a general feed for other plants.

Family: Boraginaceae
Botanical Name: Symphytum
Common Names: Comfrey, blackwort, knit-bone

Foliage: Deciduous, long oval coarse leaves.

Flowers: Terminal clusters of tubular, bell-shaped, blue, purple, pink or cream flowers.

Flowering Period: Late spring and summer.

Soil: Moist but well–drained or poorly–drained (chalk, clay, sand or loam). Acid, alkaline or neutral pH.

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

Habit: Clump forming.

Type: Rhizomatous perennial.

Origin: Europe.

Hardiness: Hardy in all of the UK.

Toxicity: Ingestion can cause severe discomfort. Skin contact can cause a rash. Wear gloves and wash hands after handling.

Planting and Growing Symphytum

Easy to grow. Plant in autumn or spring, in a moisture-retentive, moderately fertile, humus rich soil. Site in full sun or partial shade.

Excellent as low maintenance groundcover in shade. Tolerant of poor soils and neglect. Can be invasive but easily controlled by digging out any unwanted growth.

The leaves can be used as a nutrient-rich mulch or steeped in water to provide a general liquid feed.

Taking Care of Symphytum

Mulch with well-rotted manure or garden compost in spring.

Pruning Symphytum

Cut down stems in autumn to encourage fresh growth.

Pests and Diseases

Generally trouble free.

Propagating Symphytum

Seed can be sown in pots in a cold frame in autumn or spring. Alternatively, divide established clumps in autumn or spring. Root cuttings can also be taken in early winter.

Popular Varieties of Symphytum

Symphytum caucasicum blue flowers. Height to 2ft (60cm).

Symphytum 'Goldsmith' (hybrid) attractive yellow edged leaves and pink blue or yellow flowers.

Symphytum grandiflorum (creeping comfrey) creamy white flowers in April-June. Height to 1ft (30cm), spread to 3ft (90cm).

Symphytum 'Hidcote Pink' (hybrid) pink flowers.

Symphytum ibericum (Iberian comfrey) pale yellow or pink flowers. Height to 16in (40cm). For sale at Crocus. Cultivar 'Variegatum' has yellow marked leaves.

Symphytum officinale (common comfrey) robust, clump forming spreading perennial with terminal clusters of nodding, tubular purple, pink or cream flowers in summer.

Symphytum uplandicum (Russian comfrey) a taller strain with blue or purple flowers in July-August. Height to 3ft (90cm), spread 2ft (60cm) or more. Cultivar 'Variegatum' has bold cream margined leaves.