Rough blazing star
Liatris aspera · Asteraceae
The latest blazing star: tall stems studded with round, shaggy, rosy-purple buttons in late summer and early autumn. It thrives in dry, poor soil.
- Size
- 3½ ft tall, 16 in wide
- Zones
- 3 to 8
- Light
- Full sun
- Flowers
- Mid August to late September
- Pets
- No toxicity recorded
- Job in a bed
- Accent
A bed built around rough blazing star
The planner designed this bed around rough 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 715 that suit those conditions and its dry soil, and says below why rough blazing star stands where it does.
The plants
- 1 Rough blazing star × 3, purple
- 2 Dianthus 'Kahori' × 8, pink
- 3 Robin's plantain 'Lynnhaven Carpet' × 10, lavender
- 4 Stiff goldenrod × 8, yellow
- 5 Dwarf English boxwood × 1, dark green leaves
- 6 Purple milkweed × 3, purple
- 7 Daffodil 'Thalia' × 7, white
- 8 Spring starflower × 12, blue
Why this plant
- The only spires. The others are open bowls, daisies, flat plates and others. Shape reads at a distance, where colours blur.
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 stiff goldenrod (4 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 August to late September.
- Part of the bed's peak. With dianthus 'Kahori' and stiff goldenrod in mid August: 3 kinds at once. No week has more.
Planned as a cottage garden: 33 of the 33 plants (100%), bulbs aside, stand alone or in groups of no more than five, small enough for the kinds to mingle. The front edge is finished with dianthus 'Kahori' and Robin's plantain 'Lynnhaven Carpet'. The most in flower at one time is 3 kinds, from early May.
The planner's own design check: 12 Excellent, 5 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 rough blazing star 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: accent. An upright plant used singly, like a punctuation mark, and repeated at intervals to give the bed rhythm.
It flowers a month after the common blazing star, when monarchs are passing through. Lean, dry soil keeps it upright; in rich soil it flops.
- Late-summer verticals for dry soil
- Prairie and meadow planting
- Monarch butterflies on migration
What to plant with rough blazing star
Plants recorded as good partners for it, and what each pairing does:
- Little bluestem: its blue-green leaves are a setting for the flowers, before and after; happy in the same dry soil.
- Butterfly weed: flowers first, late June to early August, so the spot is never empty; low enough (24 in) to stand in front of it; happy in the same dry soil.
- Prairie dropseed: in flower together for six weeks, from mid August; a low mound at the foot of its spires; happy in the same dry soil.
Questions about rough blazing star
Does rough blazing star need sun or shade?
Rough blazing star grows in full sun (6 or more hours of direct sun a day).
It wants dry, sharply drained soil, on the lean side, with no feeding, and little watering once settled. Once settled in, it stands drought.
What zones does rough blazing star grow in?
USDA zones 3 to 8. It is hardy to zone 3, which means it survives winter nights down to about −30 °F (−34 °C).
Above zone 8 it struggles: the zones measure winter cold, but a plant's top zone usually means the summers are too hot or the winters too mild for it to rest.
Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.
When does rough blazing star flower in my zone?
In zone 5 it flowers mid August to late September. As a summer flower it moves about half a week for every zone: earlier where it is warmer.
| Zone 3 | Late August to late September |
|---|---|
| Zone 4 | Late August to late September |
| Zone 5 | Mid August to late September |
| Zone 6 | Mid August to late September |
| Zone 7 | Early August to late September |
| Zone 8 | Early August to late 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 rough blazing star be planted?
14 in (35 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 16 in (40 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 rough blazing star plants do I need?
At 14 in apart, set out in staggered rows:
- 9 to fill 10 square feet (about 1 m²)
- 9 for a single row 10 ft (3 m) long
- 28 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 rough 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 rough 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 rough blazing star?
Rough blazing star is over by late September. These start as it finishes and carry the same spot on, so it never goes flat:
- Chrysanthemum 'Sheffield Pink': from late September to early November, 2½ ft tall, to stand in front of it and cover its fading stems.
- Aromatic aster 'Raydon's Favorite': from mid September to early November, 3 ft tall.
- October daphne: from mid September to late October, 8 in tall, to stand in front of it and cover its fading stems.
What does rough blazing star look like in winter?
Rough 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 rough blazing star good for bees and butterflies?
Rough blazing star is visited by pollinators, butterflies, hummingbirds and songbirds.
It is native to the United States and Canada.
More Liatris
- Blazing star Liatris spicata
- Blazing star 'Kobold' Liatris spicata 'Kobold'
- Meadow blazing star Liatris ligulistylis
- Prairie blazing star Liatris pycnostachya
In these guides
- Drought-tolerant perennials for full sun
- Pet-safe plants for a sunny border
- Native perennials for pollinators
- Garden plants native to Canada
- Plants for hummingbirds
- Plants for butterflies
- Plants that feed garden birds
- Plants with spires: vertical accents
- Plants that flower in fall
Zone guides: Zone 3 · Zone 4 · Zone 5 · Zone 6 · Zone 7 · Zone 8
Every fact on record
- Type
- Perennial
- Size
- 3½ ft (100 cm) tall, 16 in (40 cm) wide
- Plant
- 14 in (35 cm) apart
- Height class
- Moderately tall (3 to 4 ft)
- Place in the bed
- Back
- Flowers
- Mid August to late September; upright spires; purple
- Leaves
- Fine texture, herbaceous; green
- Shape
- Upright, clumping
- Hardy in
- USDA zones 3 to 8
- Light
- Full sun
- Soil
- Lean, dry and sharply drained
- Water
- Low
- Feeding
- None needed
- Family
- Asteraceae
- Comes from
- S.E. Canada to eastern U.S.A
- Attracts
- Pollinators, butterflies, hummingbirds, songbirds
- Stands up to
- Drought
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.