Common name: False Dragonhead or Obedience plant.
Physostegia is a hardy herbaceous clump forming perennial with antirrhinum like flowers.
The 150mm (6”) long racemes of flowers that are attractive to butterflies appear from July to September.
The flower buds form on three sides of the stem with the bottom third fully open, the middle third partially open and the top third remain closed.
Physostegia in flower
Another attribute to this flower is the one that gives it its common name, and that is, if you gently twist the flower bud it will remain in that position.
Regularly thin out spent flower heads to encourage new growth.
Depending upon variety it can grow to 900mm (3ft) high making them a good subject for cut flower arrangements.
They will spread to around 600mm (24") diameter.
They can spread quite quickly so control this by digging out unwanted plants.
Sow seed in pots/trays of seed compost and germinate at a temperature of 18°-24°C (65°-75°F)
Germination should take around 8-10 days.
If ground conditions allow, divide established plants and plant the divisions immediately.
Apply 50-75 mm (2”- 3”) mulch after planting.
Take basal cuttings if available, and root them at a temperature of 10°- 12°C (50°- 54°F).
Once rooted grow them on in a cold frame until planting out time.
Prick out seedlings if large enough to handle into individual 70mm (3") pots of potting compost.
Grow on in coldframe until planting out time.
Plant out 600mm (24”) apart in a sunny or semi-shaded area if ground conditions allow.
They will tolerate moderately wet ground adjacent to ponds or water features.
Cut down plants to ground level.