Ornamental · Asteraceae
Blazing Star
Liatris spicata
Plant the corms once and blazing star sends up tall purple spikes for the bees every summer.
Full sun
USDA 3–8
2–4 ft · 0.6–1.2 m
Overview
Blazing star is a North American prairie native that trades the wide, flat flowers of most garden plants for tall, narrow spikes. Each stem packs dense purple buds that open into a fuzzy column, and a stand of them in bloom pulls in butterflies and bees from across the yard. The plant grows from a corm, comes back on its own every year, and asks very little once it's in the ground.
What sets it apart shows up at bloom time. Most spike flowers open from the bottom up, but blazing star opens from the top down, so the tip fades while the base is still coming on. The grassy foliage and stiff stems give a bed vertical lines that most perennials can't, whether you grow the full-height species or a shorter selection like 'Kobold'.
It's an easy plant for a sunny, well-drained spot. Give it full sun and ground that drains, and it shrugs off heat, drought, and poor soil once its roots are down. The one thing it won't forgive is wet feet in winter, which rots the corm faster than any pest or disease will.
Care
The short version: full sun and average, well-drained soil, regular water the first season and far less after that, and a site that never stays soggy through winter.
Light
Give blazing star full sun. It will get by in partial shade, but the stems stretch and weaken there and lean over, so the more sun it gets, the sturdier and more upright it stands.
Water
Water it through its first growing season to settle the roots in. After that it's fairly drought tolerant and needs little extra, and it would much rather run dry than sit wet, especially over winter.
Soil
It takes almost any well-drained soil, from loam to sand to clay, and even puts up with poor ground. A pH anywhere from 6.0 to 8.0 suits it, so the one thing that really matters is drainage rather than richness.
Humidity
Ordinary outdoor air is all it asks, so there's no number to chase. Good airflow counts for more here, since crowded, still conditions are what let powdery mildew and rust get a foothold.
Feeding
This is a lean-soil prairie plant and not a heavy feeder. A light feeding before growth starts in spring is plenty, and piling on fertilizer only grows soft, floppy stems that can't hold their flowers up.
Pruning
Cut the spent flower stalks once they finish, but leave the foliage and hollow stems standing through winter to shelter native bees and feed songbirds, then cut them back in early spring. Tall stems in rich, moist soil may need a stake.
Size & spacing
Plants reach 2 to 4 feet (60 to 120 cm) tall in a narrow clump. Set them about 12 to 15 inches apart so air moves freely and the spikes have room to stand.
When to plant
Blazing star is a hardy perennial for zones 3 to 8. Set out corms or young plants in early spring, or plant container-grown stock again in early fall, and the flower spikes arrive in mid- to late summer.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: Early spring; seed germinates in 20-45 days and benefits from 4-6 weeks cold moist stratification
- Plant: Plant corms or container plants in early spring; container-grown plants may also be set out in early fall, spaced 12-15 inches apart
- Harvest: Blooms mid- to late summer (July-August), with dense purple flower spikes opening from the top down
Hardiness
USDA hardiness zones: 3–8
Temperature: down to -40°C
Troubleshooting
Blazing star has few real problems, and most of them trace back to one thing: ground that holds too much water. Watch the stems and leaves through the season, and step in early before a small spot of fungus or a soggy corm spreads. Match what you see below, then act while it still helps.
Sudden wilting with a soft, rotting crown or corm
Wet, poorly drained ground invites stem and corm rot, and soil that stays soggy through winter is the usual culprit. There's no saving a rotted plant, so dig it out along with the infected soil around it. The real fix is drainage: keep blazing star out of any spot that sits wet.
Fix:
- Improve drainage and avoid wet sites
- Remove and discard affected plants and surrounding infected soil
Tall flower stems flopping or bending over
Rich, damp soil pushes out soft, lush growth that can't hold the weight of a full spike, and too much shade makes it worse. Move the plant into full sun and leaner ground, stake the tallest stems, or grow a compact cultivar like 'Kobold' that stands on its own.
Fix:
- Stake or provide support for tall stems
- Site in full sun and average, well-drained soil rather than rich, moist beds
- Choose compact cultivars such as 'Kobold'
A white powdery coating across the leaves
This is powdery mildew, a fungus that settles in late in the season when plants stand crowded and air sits still. Open things up by spacing or thinning the clump, and strip off the worst leaves so it has less to spread to.
Fix:
- Improve air circulation by spacing and thinning plants
- Remove and dispose of badly affected foliage
Orange to brown pustules dotting the leaves
Raised rust-colored spots on the undersides of the leaves point to rust fungi. Pull and destroy the marked leaves before the spores spread, and give the plants more room so air can move and the foliage dries fast after rain.
Fix:
- Remove and destroy infected leaves
- Improve spacing and air circulation
Toxicity
Good news for pet owners and parents: blazing star is safe all around. The ASPCA lists it as non-toxic to cats, dogs, and horses, and there's nothing in the leaves, stems, or corms that poisons people or grazing animals. The most a big mouthful is likely to cause is a passing stomach upset.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
The ASPCA lists blazing star as non-toxic to cats, so a nibble is nothing to worry about. A cat that gorges on any plant may bring it back up, but that's the rough leaves, not poison.
Dogs None
Safe for dogs as well, with no toxic compounds in the leaves, stems, or corms. The worst a curious dog is likely to get from a big mouthful is a passing bout of mild stomach upset.
Horses None
Horses can graze near blazing star without harm, since the plant carries nothing poisonous to them.
Rabbits None
Rabbits and other small pets can browse the foliage safely. It's a wildflower they meet in the meadow anyway.
Livestock None
Cattle, goats, and sheep are in no danger from blazing star in the pasture; it holds no toxins that trouble grazing animals.
Birds None
Birds are fine around it, and in fact songbirds like goldfinches seek out the ripe seed heads through fall and winter.
People None
No part of blazing star is poisonous to people. It's grown for its flowers rather than the table, so there's no reason to eat it, but a stray touch or taste does no harm.
Varieties
Most of the named blazing stars are bred for color or for a tidier height. These are the ones you're most likely to find.
Kobold
A compact deep-purple selection that stays short enough to hold itself up, which makes it the easy choice for the front of a border.
Floristan White
A white-flowered form that gardeners grow mainly for cutting, since the clean spikes hold up well in a vase.
Floristan Violett
A violet-flowered selection with stems strong enough to cut and carry, which is why florists reach for it.
Alba
A pure white form that tops out around 18 inches, shorter than the species and easy to fit into a small bed.
How to propagate
You can make more blazing star by splitting an established clump or by starting from seed, though one is far quicker to flower than the other.
DivisionEasy
Spring, just as leaves emerge · Establishes over one to two seasons; clumps can be divided every few years
Dividing an established clump is the surest way to get more plants. In spring, just as the leaves push up, dig the clump and pull or cut the corms and tuberous roots apart so each piece keeps at least one eye. The new divisions come up true to the parent but settle in slowly, taking a season or two to fill out.
SeedModerate
Early spring indoors or direct sow, or fall sow outdoors · Seedlings typically bloom in their second or third year
Seed takes patience. It sprouts in 20 to 45 days, but only after a cold spell wakes it up, so give the seed 4 to 6 weeks of cold, moist chilling first or simply sow it outdoors in fall and let winter do the work. From there a seedling needs its second or third year before it sends up its first flower spike.
Myths
Blazing star is poisonous to dogs and cats.
The ASPCA lists blazing star among the plants that are not toxic to dogs and cats. As with any plant, a pet that eats a big mouthful might get a mild upset stomach, but there's no poison to fear.
Liatris spikes open from the bottom up like most spike flowers.
Blazing star does the opposite of nearly every other spike flower. It blooms from the top of the spike downward, so the tip is fading while the lowest buds are still opening.