Common Name: obedient plant
Type: Herbaceous perennial
Family: Lamiaceae
Zone: 3 to 9
Height: 1.50 to 2.00 feet
Spread: 1.50 to 2.00 feet
Bloom Time: June to September
Bloom Description: White
Sun: Full sun
Water: Medium
Maintenance: Medium
Suggested Use: Naturalize, Rain Garden
Flower: Showy
Attracts: Hummingbirds
Tolerate: Deer, Clay Soil
Culture
Easily grown in average, moist, acidic, well-drained soils in full sun. Stems tend to flop in rich soils, too much shade or hot summer temperatures. Taller plants may need staking. Tolerates wet soils and some part shade.
Noteworthy Characteristics
Physostegia virginiana, commonly called obedient plant or false dragonhead, is a rhizomatous perennial that is native to North America from Quebec to Manitoba south to Florida and New Mexico. In Missouri, it is commonly found in a variety of habitats including open meadows, prairies, stream banks, gravel bars, wooded bluff bases and railroad track right-of-ways (Steyermark). Tubular, two-lipped, snapdragon-like, pink to pale lilac flowers in upright terminal spikes (each to 12-18”) bloom throughout summer (late June-September) atop square stems rising to 2-4’ tall. Flowers bloom bottom to top on each spike, with each flower being subtended by a small leaf-like bract. Stems are clad with opposite, narrow-lanceolate, sharply-toothed leaves (to 3-6” long). Species plants are noted for being aggressive spreaders in the landscape by both rhizomes and self-seeding.
Genus name comes from the Greek words physa meaning bladder and stege meaning covering in reference to the calyces which inflate as they develop.
Specific epithet is in reference to the State of Virginia which is part of the native range for this plant.
Genus members are commonly called obedient plants because each individual flower will, upon being pushed in any one direction, temporarily remain in the new position as if it were hinged. Genus members are also commonly called false dragonhead because the flowers are suggestive of the flowers of dragonhead (Dracocephalum).
'Alba' features dense spikes of pure white flowers. May also be sold as 'Alba Nana' a cultivar unrecognized by current authorities.
Problems
Rust is an occasional problem. Watch for aphids and spider mites.
Species plants can be an aggressive spreader.
Uses
Borders, cottage gardens, wild gardens, prairies or meadows.