How to Grow and Care for Obedient Plant (False Dragonhead)

Obedient plant, also known as false dragonhead, is a fast-growing perennial that is easy to grow but not so obedient in the garden where it spreads aggressively by rhizomes. However, you can manually swivel the flowers where they dutifully stay put. The beautiful flowers resemble snapdragons and slowly bloom from the bottom of the flower stalk upward. Obedient plants grow best in hot, dry regions with moderate temperatures and prefer full sun and slightly acidic soil.

Obedient Plant Care

Here are the main care requirements for growing an obedient plant.

• Plant in full sun to partial sun.
• Place in moist, well-drained, and somewhat rich soil.
• Water regularly until established.
• Divide clumps every couple of years to refresh and control plants.
  

Light

Obedient plants are happiest in full sun but they can handle partial shade, especially during dry summers.

Soil

Obedient plants are easily established and very drought-tolerant, forgiving plants. Although they prefer 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.

Water

Obedient plants should be watered once or twice a week once established.

Temperature and Humidity

These are tough plants, reliably hardy in USDA Hardiness Zones 3 to 10. They prefer hot, dry regions with a temperature of 60 to 80 degrees Fahrenheit.

Fertilizer

Don’t fertilize your obedient plants, unless they show signs of nutrient deficiencies. Less fertilizer means less aggressive spreading.

Types of Obedient Plant

There are several beautiful types of obedient plants, including these:

• Physostegia virginiana 'Pink Bouquet': A profuse bloomer with soft pink flowers, this is a good choice for northern gardeners. It typically grows between 2 to 3 feet tall.
• Physostegia virginiana 'Summer Glow': A tall grower with deep lavender-pink flowers, this variety reaches 3 to 4 feet tall.
• Physostegia virginiana 'Summer Snow' and 'Crystal Peak': Both offer bright white flowers. But 'Crystal Peak' only grows 1 foot tall.
• Physostegia virginiana 'Variegata': White edges on leaves make this variety interesting all season. It produces pink flowers and grows up to 24 inches tall.
• Physostegia virginiana 'Vivid': This plant forms short, dense clumps. It yields bright purple-pink flowers and grows up to 2 feet tall.
• Physostegia virginiana 'Miss Manners': This type does not spread as aggressively. It has a compact growth habit, white flowers, and sturdier stems less prone to drooping.
• Physostegia virginiana ‘Rosea’: This variety is slightly fragrant with large, soft pink flowers.
  

Propagating Obedient Plant

Propagate obedient plants in numerous ways, including harvested seeds, cuttings, and division.

Here's how to propagate obedient plants in the spring by taking cuttings from young, tender shoots.

1. Cut off a 5 to 6-inch long young, tender shoot with a sterile cutting tool. Cut below a leaf node.
2. Remove the shoot's lower leaves and plant it in a small container filled with potting soil.
3. Keep the soil moist but not soggy.
4. Transplant the young plant into the ground or container when new leaves have formed. You can also wait until the early fall to place them in the ground.

Mature plants will thin out in the center and can take on an open, floppy form, telling you it's time to divide them. Here's how to propagate obedient plants through division.

1. Dig up a clump of young obedient plants in the spring.
2. Divide the clump into two to three new clumps.
3. Place clumps in individual pots with potting soil.
4. Put the pots into a shady place for a few days to recover.
5. Transfer the new clumps into their permanent spots in full sun.

How to Grow Obedient Plant From Seed

Obedient plants can also be started from seed indoors about two months before planting outdoors or directly sowing in the garden in the late fall before snow is on the ground.

Take these steps for both indoor and outdoor sown seeds.

1. Harvest the seeds from the seed heads two months after blooming when the flowers are faded and dried.
2. Stratify seeds for a few months at 40 degrees Fahrenheit before planting.
3. Plant the seeds just below the surface of the soil in groups of about two to three seeds.
4. Spaced groups of seeds about 18 to 24 inches apart. It will take about a week for seeds to germinate.
5. Once the plants are a few inches tall in pots, they can be transplanted into your garden a few weeks after the last frost.

Potting and Repotting Obedient Plant

Growing obedient plants in pots is a great way to keep the flower from spreading uncontrollably. Choose a large pot, preferably 18 inches, to accommodate fast growth. Make sure the container has plenty of drainage holes. Fill the pot with rich potting soil. Take in pots during the winter so the cold does not affect sensitive roots. When roots are growing out of the drainage holes, repot to larger containers or divide when repotting.

Overwintering

Wait until spring to cut back old foliage. Leave cuttings on the plants to act as a protective winter mulch.

Common Pests & Plant Diseases

This plant has minor pest or disease issues. You may find aphids and spider mites on the plants which are easy to eliminate with blasts of water, insecticidal soap, or neem oil.

Obedient plant may encounter fungal diseases such as rust or black spot. Garden hygiene can mitigate and reduce fungal problems in any garden. Pick off and properly dispose of affected leaves immediately.

How to Get Obedient Plant to Bloom

Bloom Months

Obedient plant flowers open in late summer around August, slowly blooming from the bottom of the flower stalk upward. They should remain in bloom well into fall even through November. 

What Do Obedient Plant Flowers Look and Smell Like?

Small white, pink, or lavender unscented tubular flowers form along 10-inch long spikes, in four neat vertical rows, and begin opening from the bottom up. Flowers of the obedient plant make long-lasting cut flowers.

How to Encourage More Blooms

Full sun will produce the most blossoms. Long-season gardeners can get a second flush of blooms by deadheading the first flowers.

Common Problems With Obedient Plant

This is a very easy plant to grow. However, there are a couple of issues you want to watch for when it comes to growing obedient plants.

Bent Stems

An obedient plant's flower stalks will bend and stay bent if moved or blown over. Large plants may require staking.

Rampant Spreading and Weedy

The biggest maintenance chore is keeping the obedient plant from rampant spreading and becoming too weedy. Although the plants pull out easily enough because of the shallow roots, 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. 

Spots on Leaves

Feathery black spots on leaves may indicate black spot fungal disease. Rusty orange, yellow, brown, black, or white spots can also indicate rust fungal diseases. Do not fertilize, pick off affected leaves for proper disposal, and keep the garden clean of weeds and overgrowth.

Yellowing Leaves

The obedient plant may be showing signs of nutrient deficiencies. At that point, you can fertilize this plant but not before.