The obedient plant is an ambitious perennial
Standing tall and verdant at the midsummer season, obedient plant (Physostegia virginiana) — known as false dragonhead — is an ambitious, flowering plant that easily establishes and spreads. It is native from Quebec to Manitoba in Canada and south to Florida and New Mexico.
As a member of the mint family, obedient plants spread by rhizomes, quickly filling in garden spaces. This characteristic causes gardeners to refer to this perennial as a “not-so-obedient” garden dweller. Its value as an important summer nectar source to bees and pollinators, however, is worth its enthusiastic disobedience.
The obedient plant has upright stems with narrow leaves that grow on opposite sides of the stem, in an eye-catching green that adds visual interest to the garden. It can grow to 4 feet in height, depending on the variety grown, making this plant the perfect choice for in the back of a garden or fence border.
This perennial is tolerant to harsher growing conditions. It does not perform well in rich soil or full shade.
From July until October, showy blooms form at the top of the stem of the plant. The flowers are 1¼ inches long and a gorgeous lavender color. The flowers form an almost swordlike outline when in bloom, with three to four columns of buds that grow vertically down the stem. Their bell-like shape and nectar makes them very attractive to bees, butterflies and hummingbirds.
After blooming, pea-shaped, green seed pods evolve. The pods contain seeds that spread in the area where they are planted. Considering their success at reseeding and spreading by rhizomes, put obedient plants where they will have space to propagate and form a large grouping. Once the seeds are spent, the pods dry and become black in color. Divide obedient plants before frost but after the seeds have fallen.
Once established, obedient plants require little maintenance. Pull competing weeds that grow in the early season; once the plants reach around 1 foot in height, they will overshadow most weeds and outcompete them.
Prevent their enthusiastic garden takeover by cutting the seed pods from the stem while they are in the “green pea” shaped stage.
As a member of the mint family, they are deer resistant, so grazing should not be problematic.
To learn more about the obedient plant, visit Penn State Extension at extension.psu.edu/rain-garden-plants-obedient-plant.
If you have questions about obedient plants, native plants, pollinators or other gardening practices, call the Penn State Extension Master Gardeners of Butler County at the Garden Hotline at 724-287-4761, Ext. 7, or email butlermg@psu.edu.
Amanda Hill is a Penn State Extension Butler County Master Gardener.
