Obedient Plant (Physostegia virginiana) got its common name because you can bend the individual flowers in any direction. Unfortunately, obedient plant is not so obedient in the garden, where it can spread quite aggressively, by rhizomes.
Obedient Plant has another common name, False Dragonhead, which likely came about because of the flowers' resemblance to snapdragons.
Appearance of Obedient Plant
The long, ovate, serrated leaves are fairly non-descript during the non-flowering part of the season. Some varieties turn red in the fall.
The white, pink and lavender flowers form along spikes, in four neat vertical rows, and begin opening from the bottom up.
Although obedient plant can spread throughout the garden, the individual plants tend to be clumpers. The flower stalks will bend and stay bent if moved or blown over. Large plants may require staking and mature plants will thin out in the center and can take on an open, floppy form, telling you it's time to divide them.
Hardiness Zones and Exposure
These are tough plants, reliably hardy in USDA Hardiness Zones: 3 to 10.
Obedient plants are happiest in full sun, but they can handle partial shade, especially during dry summers.
The flowers begin to open in late summer, slowly blooming from the bottom of the flower stalk upward. They should remain in bloom well into fall.
Design Tips for Obedient Plant
Obedient plant combines well with the blue flowers of the late summer garden, like Caryopteris, Russian sage, and Catmint. The spiky flowers are also a nice contract with asters, sedum, and coneflowers. Because of its obedient habit, it’s a fun plant for children’s gardens. Flowers of the obedient plant make long-lasting cut flowers.
Suggested Varieties of Obedient Plant
- Physostegia virginiana: "Pink Bouquet": Profuse bloomer with soft pink flowers. Good choice for northern gardeners. Typically grows between 2 and 3 feet tall.
- Physostegia virginiana "Summer Glow": A tall grower with deep lavender-pink flowers. Reaches heights of 3 to 4 feet tall.
- Physostegia virginiana "Variegata": White edges on leaves make this variety interesting all season. Produces pink flowers and grows up to 24 inches tall.
- Physostegia virginiana "Vivid": Forms short, dense clumps. Produces bright purple-pink flowers and grows up to 2 feet tall.
Growing Tips for Obedient Plant
Obedient plants are easily established and very drought tolerant, forgiving plants. Although they prefer a moist, slightly acidic soil (5.5 to 6.3 pH), they’ll grow just fine in average to poor soil and spreading will be less of a problem.
Don’t fertilize your obedient plants, unless they show signs of nutrient deficiencies. Less fertilizer means less aggressive spreading.
Maintaining Obedient Plant
The biggest maintenance chore is keeping obedient plant from rampant spreading. Although the plants pull out easily enough, they seem to pop up everywhere. If you’re tempted to wait and let them flower, be sure to get out there before they go to seed.
Long season gardeners can get a second flush of blooms if you deadhead the first flowers. This will also cut down on the self-seeding.
Wait until spring to cut back old foliage. Leave it on the plants to act as a protective winter mulch.
Problems and Pests:
Obedient plant is not bothered by insects, except the occasional slug. Some seasons rust can be a problem. Obedient plant is deer resistant.