Description of Physostegia virginiana (Obedient Plant)

Physostegia virginiana is obedient plant, a late summer bloomer for damp soil. It gets its name because you can gently move the flowers on the spike and they stay in place. It’s great for adding height and colour when early-season bog plants have finished.

Appearance

It forms upright stems with narrow leaves. Flower spikes carry tubular blooms, usually pink to mauve, through late summer. Height is often 60 to 100cm depending on moisture and feeding. In good soil it can spread and form patches.

Care Guide

It likes sun and moisture. It can handle boggy ground, but it doesn’t need standing water.

• Sun: Full sun gives the best flowering, part shade is fine in moist soil.
• Soil: Moist, fertile soil with organic matter.
• Water: Keep evenly moist through summer.
• Control: It can spread by runners. Lift and thin edges if needed.
• Cut back: Cut stems down after flowering or in late winter.

Deadheading can tidy the plant, but leaving some seed heads can help wildlife and gives a more natural look.

Suitability for Bog Garden

This suits bog gardens on the upper edge and in damp beds beside ponds. It works well behind lower ground covers and in front of taller reeds and shrubs.

If your bog garden is small, grow it in a basket or contained pocket so it doesn’t wander.

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