Physostegia

Physostegia summer snow

Hardy herbaceous, rhizomatous perennials with spikes of two-lipped funnel-shaped flowers. The flowers stay in position if moved from side to side, hence its common name.

Family: Lamiaceae
Botanical Name: Physostegia (fi-so-stee-gee-a)
Common Names: Obedient plant, False Dragon's Head

Foliage: Deciduous, light green broadly lanceolate, toothed leaves.

Flowers: Stout spikes of tubular, lipped flowers on opposite sides, tapering up to a point. Available in shades of white, pink or lilac.

Flowering Period: Summer to early autumn (July to September).

Soil: Moist but well-drained, fertile soil (chalk, clay, sand or loam). Acid, alkaline or neutral pH.

Conditions: Full sun or partial shade. Plant in an east, west or south facing aspect.

Habit: Upright.

Type: Rhizomatous herbaceous perennial.

Origin: North America.

Hardiness: Hardy in the UK.

Planting and Growing Physostegia

Easy to grow. Thrives on any good garden soil, providing it is reasonably fertile and well drained. Grow in full sun or partial shade.

Apply a surface mulch of garden compost between the plants to help retain moisture during the summer.

Ideal for flower beds or front/middle of the border.

Long lasting as cut flowers.

Taking Care of Physostegia

Stake taller varieties as they grow. Water well in dry weather.

Lift and divided plants every two or three years in early spring to restore vigour.

Pruning Physostegia

Cut down plants in winter.

Pests and Diseases

Generally pest and disease free.

Propagating Physostegia

Divide established clumps in autumn or early spring by dividing the fibrous, creeping roots.

Cuttings of young shoots 3in (7.5cm) long can be taken in the spring each year. Root in a light sandy compost and place under the protection of a cold frame.

Popular Varieties of Physostegia

Physostegia virginiana (the only garden worthy species) is a sturdy erect plant with stout stems and terminal spikes of deep pink, tubular flowers. Height to 3ft (90cm). Good cultivars include:

  • 'Summer snow' with spikes of pure white flowers, in summer. Height 32in (80cm). For sale at Thompson & Morgan.
  • 'Rose Bouquet' bears rose-purple flowers in autumn. Height 28in (75cm).
  • 'Vivid' is a more compact form with spikes of bright pink tubular flowers in autumn. Height 18in (45cm).