Physostegia

( fye - soh - STEE - jee - uh )

At-A-Glance Information

This genus of flowering rhizomatous perennials, often called False Dragonheads, Lionshearts or Obedient Plants, is native to eastern and central North America. Plants typically reach up to between 4 and 7 feet tall when mature. Species require full sun to partial shade and regular water for best performance. These plants will spread to form clumps using underground rhizome roots, and can become a bit of an issue if not controlled. Flowers appear in summer or early fall, resembling those of Snapdragon species. These plants are great for borders and mixed planting beds, and also make beautiful additions to cut flower arrangements.

Physostegia species and varietals

The genus Physostegia is a member of the plant family Lamiaceae and includes 12 species. ​The genus name is derived from the Greek words 'physa' (meaning bladder) and 'stege' (a covering), referring to the calyx, which is filled with fruits when mature. False Dragonhead grows best in zones A2, A3, 1-9 and 14-24. To find your zone, click here: Zone Map.

Physostegia correllii (Correll's False Dragonhead)
These plants are native to northern Mexico, Texas, and Louisiana. They are threatened with extinction, and have not been seen in their native range for quite some time now. Flowers are purple with dark streaks, and are pollinated by bumblebees. These wetland plants typically grow in drainage ditches or other moist grounds. They can grow to reach over 6 feet tall.

Physostegia godfreyi (Appalachia Dragonhead, Godfrey's False Dragonhead)
This short-lived perennial species of False Dragonhead is endemic to the Florida Panhandle, and reaches about 1.5 feet tall when mature and in bloom. Flowers are lavender-purple, and bloom in spring and summertime. These plants prefer open, wet savannah landscapes. 
Physostegia virginiana (Obedient Plant, Obedience, False Dragonhead)
These plants are native to a large area from eastern Canada through northern Mexico, and represent the most widely grown species in the genus Physostegia. These plants reach between 2 and 4 feet tall and have green lanceolate leaves. Flowers are tubular and pink, and are fantastic for adding late-season color to gardens.
'Alba'
With white flowers.
'Crown of Snow'
With white blossoms.
'Pink Bouquet'
This variety has rose pink flowers.
'Rosea'
With pink blooms.
'Rosy Spire'
This cultivar has lavender-pink flowers.
'Summer Snow'
With pure white flowers.
'Variegata'
With pink flowers and white-variegated foliage.
'Vivid'
​With bright pink flowers.

Caring for Physostegia

Plant Physostegia, or Obedient Plant, in full sun. Ideally, these plants appreciate between 6 and 8 hours of sun during the day to flower and otherwise perform well, but they can handle partial shade. In areas that experience hot, dry summers, make sure they get some afternoon shade when temperatures are at their peak (typically between 2 and 3 PM). They prefer soil that is well-draining and moderately fertile with a pH of between 5.5 and 6.3 (slightly acidic). If local soils are particularly poor in nutrients or do not drain well, make sure to amend the planting area with plenty of organic compost before installing. Apply a layer of mulch around the planting area to suppress weed growth, maintain consistent soil temperatures, and to increase soil moisture retention. Water new plantings regularly as they establish a strong root system in their new home. At maturity, these plants are considered to be drought-tolerant, but will perform better in consistently moist soils.

Do not fertilize these plants; it will increase their proclivity for spreading out of their bounds. Pruning is simple; remove any damaged, diseased, or dead foliage at any time during the growing season, and remove spent flower spikes to neaten up the appearance of plants and encourage reblooms. Some taller varieties of Obedient Plant may require staking or netting to remain upright. After blooms fade, cut the entire plant back to the ground. These plants, due to their clumping, spreading nature, will need to be divided every two years in springtime. For instructions on how to successfully divide Physostegia, see the Propagation section below.

Propagation

Physostegia, or Obedient Plant, can be propagated by division, cutting or seed. To ensure that your propagated plant will have the exact same qualities and characteristics as the parent plant, use the division or cutting method. If you would like to experiment and see what plant you can grow from seed, just keep in mind that it will not necessarily be the same as the parent plant, especially if you are propagating a hybrid cultivar. To propagate your Obedient Plant, follow the instructions below:

Propagating Physostegia by Seed
  1. Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. If you don't have any potting medium on hand, you can make some. Just mix together equal parts (by volume) moss peat and horticultural-grade sand or grit sand. You will also, after a few weeks, need individual 3-inch pots for each seedling that grows.
  2. Harvest your seeds. The seed heads on plants are pretty easy to spot, they're left behind after flowers have faded. Once they have dried out and begun to split open, you can harvest the seeds inside. Cut them off of the plant, placing them in a paper bag. Harvest as many as you can, and place the paper bag in a dry, cool, dark area. They will continue to split open and release the seeds contained inside. Once they have been released, take them out of the bag and put them in a container so you can work with them.
  3. Physostegia seeds will need a period of cold-stratification in order to germinate. To complete this process, first place seeds in a bag or other sealable container filled with moistened sand or peat moss. Then, place the container in the refrigerator (or similarly cool, dark space) for 2-3 months. The ideal temperature for cold-stratification is around 40 degrees Fahrenheit. After this period has passed, remove seeds from the container.
  4. Get your container prepared. Water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a quarter inch to a half-inch under the soil surface. Cover them with soil and water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination usually takes 2-6 weeks from sowing. Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
  5. Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 65 and 72 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (after the danger of frost has passed), when you can transplant it to its new home.

Propagating Physostegia by Cutting
  1. Gather your materials. You'll need a clean, sanitized, sharp pair of garden shears, rooting hormone, a pencil, and a 3-inch pot filled with well-draining compost or other organic material. If you don't have any potting medium on hand, you can make some. Just mix together equal parts (by volume) moss peat and horticultural-grade sand or grit sand.
  2. In early summertime, choose the plant that you'd like to propagate. Ensure that this plant has had a good watering the night before, as this will improve the chances your cutting will take root. Cut one or more 3-4 inch portion(s) of the end of a non-blooming branch and strip the leaves off of the lower half. Make a hole in your planting medium by pushing your pencil into the soil. Dip the end of the stem in rooting hormone, and plant it in your pot. Fill in soil around the cutting to support it, but do not pack it down too much.
  3. Moisten with water, and ensure that the pot has good drainage. Your pot should be kept in warm, sunny conditions indoors (and not in direct sunlight). Water whenever your soil is dry under the top layer. After about four to six weeks have passed, your cutting should be rooted. When you notice new growth, you'll know you have roots.
  4. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring, when you can transplant it to its new home. Ensure that the last frost of the year has occurred before doing this, as it can seriously damage your new plant.

Propagating Physostegia by Division
This type of propagation is relatively simple; you will need a clean shovel, mulch, fresh soil (any kind will do, though it does need to be well-draining), compost and pots (only necessary if you will be saving divided plants for transporting elsewhere). Division is best done in very early spring (after the plant has entered dormancy, but before it has begun its new spring growth), and needs to be done every few years regardless of whether you have the goal of propagating the plants for best performance. To propagate by division, follow these steps:
  1. Using a shovel, dig up your existing plant. Start from the outside and work your way in to avoid damaging the root(s). Once you have worked it up out of the ground, lay it out.
  2. Start to tease apart the roots with your gloved fingers. Once the roots are untangled, separate your plant into segments, ensuring that each one has at least one thick root section attached.
  3. Prepare your pot(s) or new planting site(s) with amended, well-draining soil. You can either bring in new soil or simply amend your existing soil with compost to complete this task. Then, plant your divisions and water thoroughly.
  4. Apply a thick layer of mulch over the new planting to protect it from cold weather as it acclimates to its new home. Then, enjoy watching it sprout in the next growing season.
Physostegia seed pods, ready to spill their contents.
Physostegia seeds are very small, and are typically dark brown to blackish in color.

Problems and Pests

Physostegia, or Lionsheart, ​plants can be susceptible to developing issues with the following pests and diseases in the landscape:
  • Root Rot
  • Aphids
  • Spider Mites
  • Thrips
For more information on these pests and diseases, including how to treat and prevent them, consult the following pages:
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Gallery

Obedient Plants do a great job at filling in bare spaces in the landscape.
These flowers naturally grow in moist soils near bodies of water.
Bees are important pollinators of Physostegia flowers.
There are white-blooming varieties of Obedient Plant.
This informal garden features Lespedeza, Catmint, and various evergreen shrubs alongside False Dragonhead.
False Dragonhead spreads via underground rhizome roots, especially in moist soil.
Flowering stems are harvested from these plants and used in fresh arrangements.
Physostegia flowers bloom from the bottom of the stalk upwards towards the tip.
This mixed bed features Obedient Plant alongside Leopard's Bane.

Videos

All about growing Obedient Plant.
Learn about the great benefits of planting these flowers in your landscape.
Plant Physostegias to feed the bees.
Obedient Plants don't always live up to their common name.

Resources

Physostegia - Growing Guide
How to Plant and Grow Obedient Plant
Physostegia virginiana (False Dragonhead, Obedient Plant, Virginia Lions-heart)
How to Grow and Care for Obedient Plant (False Dragonhead)
Wikipedia: Physostegia
The New Sunset Western Garden Book: The Ultimate Gardening Guide (2012) - Page 504, Physostegia virginiana
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