Obedient? Maybe…Maybe Not
Most of my garden beds are full-shade; I have a few spots which are partly shady and very, very few which receive six hours of sun. Although I really love hostas, astilbes and ferns, it's nice to find other plants to add some variety and color. If it's a native plant, that's all the better!
Obedient Plant or False Dragonhead (Physostegia virginiana) is quite pretty, with pink or white blooms from June to September in my Zone 6b. Hummingbirds, butterflies and other pollinators find it very attractive and because it blooms into the fall season, it extends the food supply for these critters.
It's a native of North America, growing from Zones 3 to 9, tolerates clay soil and isn't particularly attractive to deer.
Although it grows best in full sun and medium to moist soils, that isn't where I planted it – and I had two good reasons! One, I don't have much in the way of full sun, and two, if it's planted where it really can thrive, it can take over your garden! Why? It's a rhizomatous member of the mint family; it will spread by underground rhizomes in addition to re-seeding itself.
Now this isn't necessarily bad; if you have a moist, boggy area in full sun, and really want something to take over, go ahead and use Obedient Plant. If you want just a little of it, plant it in a marginal spot, where it will live and bloom, but not "go hog wild and pig crazy". Another way to keep it in bounds is to plant it inside a bucket with the bottom removed.
Pinch it back if it starts getting leggy, you'll get more flower stalks and will hopefully avoid the need to stake it.
The growing awareness of the importance of native plants has led to greater availability and new cultivars. "Miss Manners" has white blooms and doesn't spread so aggressively; "Variegata" has pink flowers with green and white variegated leaves and is supposed to be less aggressive.
The three obedient plants I put in this spring were in a partly shady and fairly dry spot. They survived – of course it rained nearly every day this summer. The pale pink blooms glowed in the shade. I expect they'll survive our generally mild winter and come back again next spring. There's a saying that "perennials sleep, creep, then leap" so I'll keep an eye on them...just to make sure they aren't being too aggressive.