Prairie blazing star
Liatris pycnostachya · Asteraceae
The tallest blazing star, with long, dense, lilac-purple spikes like bottle brushes on stems clothed in grassy leaves. A plant of moist prairies.
- Size
- 4 ft tall, 18 in wide
- Zones
- 3 to 9
- Light
- Full sun
- Flowers
- Mid July to late August
- Pets
- No toxicity recorded
- Job in a bed
- Accent
A bed built around prairie blazing star
The planner designed this bed around prairie blazing star 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 prairie blazing star stands where it does.
The plants
- 1 Prairie blazing star × 3, purple
- 2 Winter heath × 8, pink
- 3 Coral bells 'Firefly' × 14, red
- 4 Turtlehead 'Hot Lips' × 5, pink
- 5 Silver sage × 1, silver leaves
- 6 Gray's sedge × 3, green
- 7 Iris 'Katharine Hodgkin' × 10, blue
- 8 Tulip 'Ballerina' × 7, orange
Why this plant
- The only purple.
Why here
- Anchors a back corner. At 4 ft it is the tallest plant 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 Gray's sedge (2½ ft): no two neighbours there are the same height, so the back steps up and down like a skyline.
- 3 plants in one clump. A single spire is too slight to hold a place alone, so here the accent is a clump.
Why now
- In flower for 7 weeks. From mid July to late August.
- Part of the bed's peak. With coral bells 'Firefly' and Gray's sedge in mid July: 3 kinds at once. No week has more.
Planned as a cottage garden: 34 of the 34 plants (100%), bulbs aside, stand alone or in groups of no more than five, small enough for the kinds to mingle. The bed is balanced: the left half carries 47% of the visual weight and the right half 53%. The longest in flower is Gray's sedge: 15 weeks, from late May to early September.
The planner's own design check: 13 Excellent, 4 Good. It flags one thing to watch: Nothing on this plan is highly poisonous or an aggressive spreader.
Open this bed in the planner Change its size, the sun or the style, move plants about, or swap one for another.
Where prairie blazing star goes in a border
At 4 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: accent. An upright plant used singly, like a punctuation mark, and repeated at intervals to give the bed rhythm.
Best grown through grasses and other prairie plants, which hold up its tall spikes. On its own in rich garden soil it leans.
- Tall vertical accents
- Moist meadows and rain gardens
- Butterfly gardens
What to plant with prairie blazing star
Plants recorded as good partners for it, and what each pairing does:
- Culver's root: in flower together for five weeks, from mid July.
- Switchgrass 'Shenandoah': its green leaves are a setting for the flowers, before and after.
- Purple coneflower: in flower together for seven weeks, from mid July.
Questions about prairie blazing star
Does prairie blazing star need sun or shade?
Prairie blazing star grows in full sun (6 or more hours of direct sun a day).
It wants ordinary well-drained soil, of average fertility, and a good soak in dry spells. Once settled in, it stands drought.
What zones does prairie blazing star 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 prairie blazing star flower in my zone?
In zone 5 it flowers mid July to late August. As a summer flower it moves about half a week for every zone: earlier where it is warmer.
| Zone 3 | Late July to early September |
|---|---|
| Zone 4 | Late July to early September |
| Zone 5 | Mid July to late August |
| Zone 6 | Mid July to late August |
| Zone 7 | Mid July to late August |
| Zone 8 | Mid July to late August |
| Zone 9 | Early July to mid August |
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 prairie blazing star be planted?
16 in (40 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 18 in (45 cm), so a group knits into one patch.
It grows 4 ft (120 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many prairie blazing star plants do I need?
At 16 in apart, set out in staggered rows:
- 7 to fill 10 square feet (about 1 m²)
- 8 for a single row 10 ft (3 m) long
- 21 to fill a 4 × 8 ft bed on its own
In a mixed border, plant it as one at a time, repeated along the bed at intervals; a slender one reads better as a clump of three.
In the bed above, the planner used three in one group.
Is prairie blazing star 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 prairie blazing star?
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.
What flowers after prairie blazing star?
Prairie blazing star is over by late August. 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.
- Montauk daisy: from mid September to late October, 3 ft tall, to stand in front of it and cover its fading stems.
- New York aster: from late August to mid October, 3 ft tall, to stand in front of it and cover its fading stems.
What does prairie blazing star look like in winter?
Prairie blazing star dies down, but leave the stems standing: the seed heads stand through the winter, and songbirds eat the seed. Cut them down in early spring, before the new shoots come.
Is prairie blazing star good for bees and butterflies?
Prairie blazing star is visited by butterflies, hummingbirds and songbirds.
It is native to the United States.
More Liatris
- Blazing star Liatris spicata
- Blazing star 'Kobold' Liatris spicata 'Kobold'
- Meadow blazing star Liatris ligulistylis
- Rough blazing star Liatris aspera
In these guides
- Drought-tolerant perennials for full sun
- Pet-safe plants for a sunny border
- Native perennials for pollinators
- Plants for hummingbirds
- Plants for butterflies
- Plants that feed garden birds
- Tall perennials and grasses for the back of a border
- Plants with spires: vertical accents
Zone guides: Zone 3 · Zone 4 · Zone 5 · Zone 6 · Zone 7 · Zone 8 · Zone 9
Every fact on record
- Type
- Perennial
- Size
- 4 ft (120 cm) tall, 18 in (45 cm) wide
- Plant
- 16 in (40 cm) apart
- Height class
- Moderately tall (3 to 4 ft)
- Place in the bed
- Back
- Flowers
- Mid July to late August; upright spires; purple
- Leaves
- Fine texture, herbaceous; green
- Shape
- Upright, clumping
- Hardy in
- USDA zones 3 to 9
- Light
- Full sun
- Soil
- Average, well-drained
- Water
- Moderate
- Feeding
- None needed
- Family
- Asteraceae
- Comes from
- Central U.S.A
- Attracts
- Butterflies, hummingbirds, songbirds
- Stands up to
- Drought, heat, humidity
Checked against NC State Extension and VASCAN (plants of Canada). 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.