Obedient plant
Physostegia virginiana · Lamiaceae
Neat spikes of pink or white, snapdragon-like flowers in late summer. The flowers stay where you push them, hence the name; the plant itself does not.
- Size
- 3½ ft tall, 2½ ft wide
- Zones
- 3 to 9
- Light
- Full sun to part sun
- Flowers
- Early August to mid September
- Pets
- No toxicity recorded
- Job in a bed
- Drift
A bed built around obedient plant
The planner designed this bed around obedient plant when this page was made: a 12 × 6 ft (3.7 × 1.8 m) cottage garden in zone 6, full sun. It chose the other plants from the 966 that suit those conditions, and says below why obedient plant stands where it does.
The plants
- 1 Obedient plant × 3, pink
- 2 Creeping phlox 'Candy Stripe' × 5, pink
- 3 Sea thrift × 8, white
- 4 Switchgrass 'Shenandoah' × 1, green leaves
- 5 Deutzia 'Chardonnay Pearls' × 1, white
- 6 Wild quinine × 3, white
- 7 Grape hyacinth × 12, blue
- 8 Star of Persia × 5, purple
Why this plant
- A classic partner for switchgrass 'Shenandoah'. Both are on this plan. A pairing gardeners have proved outranks a general rule.
- The only medium leaves here. The rest are fine and bold. A change of leaf keeps plants distinct when nothing is in flower.
Why here
- Anchors a back corner. At 3½ ft it is among the tallest plants here, and the tallest close the ends of the bed, where they stand in front of nothing.
- A step in the back row. Next to deutzia 'Chardonnay Pearls' (2½ ft): no two neighbours there are the same height, so the back steps up and down like a skyline.
- 3 plants in one group. Massed, one kind reads as a single shape. Scattered, it would look spotty.
Why now
- In flower for 7 weeks. From early August to mid September.
- Closes the season. For its last four weeks nothing else on the plan is in flower.
Planned as a cottage garden: 21 of the 21 plants (100%), bulbs aside, stand alone or in groups of no more than five, small enough for the kinds to mingle. Pink, blue, purple and white make a cool, restful scheme. Creeping phlox 'Candy Stripe' stands beside grape hyacinth, a proven pairing.
The planner's own design check: 12 Excellent, 4 Good, 1 Satisfactory. It flags one thing to watch: Obedient plant spreads aggressively. Each plant's details say more.
Open this bed in the planner Change its size, the sun or the style, move plants about, or swap one for another.
Where obedient plant goes in a border
At 3½ ft it belongs at the back of a bed. In the planner's ten height classes it is moderately tall (3 to 4 ft).
Its job: drift. Planted in a small group of three or five, and repeated further along in the other number.
It runs fast in moist, rich soil. Use it where that is welcome, or choose 'Miss Manners', which stays in a clump.
- Late-summer spires for moist soil
- Naturalising in rain gardens and meadows
- Cut flowers
What to plant with obedient plant
Plants recorded as good partners for it, and what each pairing does:
- New England aster: in flower together for three weeks, from early September; happy in the same moist soil.
- Joe Pye weed 'Gateway': in flower together for six weeks, from early August; bold leaves against its medium ones; tall enough (6 ft) to stand behind it.
- Switchgrass 'Shenandoah': its green leaves are a setting for the flowers, before and after.
Questions about obedient plant
Does obedient plant need sun or shade?
Obedient plant grows in full sun (6 or more hours of direct sun a day) and part sun (4 to 6 hours of sun, including some afternoon sun).
It wants soil that stays evenly moist, of average fertility, and a good soak in dry spells.
What zones does obedient plant grow in?
USDA zones 3 to 9. It is hardy to zone 3, which means it survives winter nights down to about −30 °F (−34 °C).
Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.
When does obedient plant flower in my zone?
In zone 5 it flowers early August to mid September. As a summer flower it moves about half a week for every zone: earlier where it is warmer.
| Zone 3 | Mid August to mid September |
|---|---|
| Zone 4 | Mid August to mid September |
| Zone 5 | Early August to mid September |
| Zone 6 | Early August to mid September |
| Zone 7 | Early August to mid September |
| Zone 8 | Early August to mid September |
| Zone 9 | Late July to mid September |
Worked out from Hopkins' bioclimatic law: spring arrives about four days later for each degree of latitude north, and one zone is roughly two degrees. A warm spring or a cold one moves any garden two weeks either way.
How far apart should obedient plant be planted?
24 in (60 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 2½ ft (75 cm), so a group knits into one patch.
It grows 3½ ft (100 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many obedient plant plants do I need?
At 24 in apart, set out in staggered rows:
- 3 to fill 10 square feet (about 1 m²)
- 6 for a single row 10 ft (3 m) long
- 10 to fill a 4 × 8 ft bed on its own
In a mixed border, plant it as a group of three or five, with a second group further along in the other number.
In the bed above, the planner used three in one group.
Is obedient plant poisonous to dogs and cats?
No toxicity is recorded for dogs, cats, horses or people, according to NC State Extension.
"Not toxic" is not "edible": a pet that eats a lot of any plant can be sick.
Do deer eat obedient plant?
They may. NC State does not list it as resistant to deer or rabbits. Where they visit, protect it, or plant it among ones they avoid.
Will obedient plant spread?
It spreads sideways, by runners or roots; the risk of it taking over is high. Spreads aggressively by underground runners and is hard to remove once established. Plant it only where it can be contained.
What flowers after obedient plant?
Obedient plant is over by mid September. These start as it finishes and carry the same spot on, so it never goes flat:
- Garden chrysanthemum: from mid September to late October, 24 in tall, to stand in front of it and cover its fading stems.
- Blue wood aster: from mid September to mid October, 3 ft tall.
- Montauk daisy: from mid September to late October, 3 ft tall.
What does obedient plant look like in winter?
Obedient plant dies down to the ground and there is nothing to see until spring. The old stems can be cut in autumn, or left until spring as shelter for overwintering insects.
Is obedient plant good for bees and butterflies?
Obedient plant is visited by pollinators, bees, butterflies and hummingbirds.
It is native to the United States and Canada.
More Physostegia
- Obedient plant 'Miss Manners' Physostegia virginiana 'Miss Manners'
In these guides
- Pet-safe plants for a sunny border
- Native perennials for pollinators
- Garden plants native to Canada
- Plants for hummingbirds
- Plants for butterflies
- Plants for bees
- Plants with spires: vertical accents
- Plants for a white garden
Zone guides: Zone 3 · Zone 4 · Zone 5 · Zone 6 · Zone 7 · Zone 8 · Zone 9
Every fact on record
- Type
- Perennial
- Size
- 3½ ft (100 cm) tall, 2½ ft (75 cm) wide
- Plant
- 24 in (60 cm) apart
- Height class
- Moderately tall (3 to 4 ft)
- Place in the bed
- Back
- Flowers
- Early August to mid September; upright spires; pink, white
- Leaves
- Medium texture, herbaceous; green
- Shape
- Upright, spreading
- Hardy in
- USDA zones 3 to 9
- Light
- Full sun, part sun
- Soil
- Average, evenly moist
- Water
- Moderate
- Feeding
- None needed
- Family
- Lamiaceae
- Comes from
- Eastern North America, North Carolina
- Attracts
- Pollinators, bees, butterflies, hummingbirds
Checked against NC State Extension. Flowering times are for zone 5: later in colder zones, earlier in warmer ones. Toxicity and spread information is a general gardening guide, not veterinary or medical advice, and invasive status varies by region. If a person or pet eats a plant, contact poison control or a vet. Check your local invasive species list before planting anything with a spread warning.