Plant liatris (blazing star) corms or potted plants in spring after your last frost, as early as you can, or in late summer to early fall once it cools (UF/IFAS). Give them full sun and well-drained soil, 12 to 15 inches apart (Wisconsin Extension). Corm depth advice ranges from 1 to 2 inches (Ask Extension) to 3 inches (Fairfax Master Gardeners) to about 5 inches (NC State). Corms planted in spring can bloom the same summer, about 70 to 90 days later (UF/IFAS, Fairfax Master Gardeners).
Liatris, also called blazing star or gayfeather, is a North American native perennial in the aster family (NC State). It sends up tall spikes of purple, pink or white flowers in late summer, and unlike most spiky flowers, the spikes open from the top down (Wisconsin Extension). Depending on the species, liatris grows from a corm, a rhizome or a root crown, and spikes range from 1 to 5 feet tall (Wisconsin Extension). The grassy leaves turn bronze in fall (Wisconsin Extension).
When to plant liatris
| Timing | What to plant and when |
|---|---|
| Spring (most areas) | Plant corms or potted plants as early as possible in spring after your last frost (UF/IFAS). Wisconsin Extension says container plants are best planted in early spring |
| Late summer to early fall | A second window once cooler weather returns (UF/IFAS); Wisconsin Extension also lists early fall for container plants |
| Seed | Sow outdoors in fall or early winter so seeds get 4 to 6 weeks of cold, moist conditions, or start indoors or sow in early spring after cold stratification (Wisconsin Extension) |
| Dividing clumps | Dig and divide in spring just as the leaves come up (Wisconsin Extension, UF/IFAS) |
Our planting calendar shows your average last spring frost. Plant liatris corms after that date, around the time you plant gladiolus and dahlias (GardenPal suggestion). Liatris is hardy across a wide range, zones 3a to 9b for the genus (NC State), so in most gardens the corms can stay in the ground over winter.
How deep and far apart to plant liatris
| Liatris corms and plants | |
|---|---|
| Depth | 1 to 2 in (Ask Extension); 3 in (Fairfax Master Gardeners); about 5 in (NC State). Sources differ, so a middle depth of 2 to 3 inches is a reasonable start in heavier soil (GardenPal note) |
| Spacing | 12 to 15 in apart (Wisconsin Extension, UF/IFAS, Fairfax Master Gardeners); NC State and Ask Extension use 6 to 8 in for corms |
| Which way up | Flat side down, growing tips up (Fairfax Master Gardeners, Ask Extension) |
| Light | Full sun is best; tolerates some shade (Wisconsin Extension, NC State) |
| Soil | Well-drained. Liatris tolerates poor soil, and rich soil can make spikes flop (Wisconsin Extension). L. spicata likes average to moist, acidic to neutral soil (NC State) |
| Corm storage | Keep corms cool until planting; refrigerate them if you store them longer than three weeks (NC State) |
Watering, feeding and staking
- Water the first season. Water regularly the first year to build roots; after that, liatris is fairly drought tolerant (Wisconsin Extension).
- Don't drown it. Plants rot if the soil stays too wet, and good drainage helps them survive wet winters (Wisconsin Extension). Fairfax Master Gardeners say liatris dislikes saturated soil.
- Feed lightly. Fertilize before new growth starts in spring, but don't overdo it; too much fertility makes some kinds flop (UF/IFAS).
- Staking: most stay upright, but tall L. spicata stems may need staking (NC State), especially in very fertile, moist soil (Wisconsin Extension).
- Cutting: for dried flowers, cut spikes when half to two-thirds of the flowers are open and hang them upside down for about three weeks (Wisconsin Extension).
Liatris in containers
Wisconsin Extension recommends compact cultivars such as 'Kobold' for the front of a border, and the same short, dense habit suits a large pot (GardenPal suggestion). Use a free-draining mix, since wet soil rots the corms (Wisconsin Extension). Potted corms are less protected from cold than corms in the ground, so move the pot to a sheltered spot in winter in cold zones (GardenPal note).
Fall cleanup and winter
- Leave some stems. NC State suggests cutting dead stems back to 12 to 24 inches instead of to the ground so stem-nesting bees can use them.
- Mulch after freeze-up: Ask Extension suggests mulching the bed after the ground has frozen.
- Saving seed: Fairfax Master Gardeners collect seed once the whole spike has turned fluffy and tan, air-dry it, and store it sealed in the refrigerator.
Pests and problems
Liatris has no significant insect problems apart from flea beetles in some places (UF/IFAS). Diseases include leaf spots, rusts, stem rot, powdery mildew and Verticillium wilt (Wisconsin Extension), and good spacing for sun and air helps limit them. Deer don't favor liatris, but voles may eat the corms (Fairfax Master Gardeners). It is also a host plant for the liatris flower moth and liatris borer moth (NC State).
Liatris around the vegetable garden
Liatris flowers draw bees, butterflies and other insects (Wisconsin Extension), and a Fairfax Master Gardener reports that planting it in her vegetable garden brought more bees to her tomatoes. Wisconsin Extension pairs the purple spikes with yellow flowers such as cosmos, coreopsis and goldenrod, or with pink purple coneflower. Plant a drift along the edge of the tomato or squash bed, where its upright form won't shade crops (GardenPal suggestion). For more pollinator plants, see flowers that attract beneficial insects and when to plant cosmos.
Frequently asked questions
When should I plant liatris bulbs?
As early as possible in spring after the last frost, or in late summer to early fall when it cools (UF/IFAS).
How deep do you plant liatris corms?
Sources vary: 1 to 2 inches (Ask Extension), 3 inches with the flat side down (Fairfax Master Gardeners), or about 5 inches (NC State).
Will liatris bloom the first year?
Corms and potted plants often bloom the year they are planted (UF/IFAS), about 70 to 90 days after planting (Fairfax Master Gardeners). Seed-grown plants usually take two to three years (Wisconsin Extension).
How far apart should liatris be planted?
12 to 15 inches apart in full sun (Wisconsin Extension, UF/IFAS).
Does liatris come back every year?
Yes. It is a perennial, and NC State lists the genus as hardy in zones 3a to 9b.
Why is my liatris falling over?
Very rich, moist soil and too much fertilizer can make the spikes flop (Wisconsin Extension, UF/IFAS). Tall L. spicata may need staking (NC State).
Enter your frost dates to see your last spring frost and time your liatris planting.
Open itSources
- Virginia Cooperative Extension, "Companion Planting in Gardening" (SPES-620P)
- University of Maryland Extension, "Vegetable Succession and Companion Planting"
- Oregon State University Extension, "Companion Planting"
- Penn State Extension, "Herbs Make Good Plant Partners and Companions"
- University of Minnesota Extension, "Planting the vegetable garden"
- USDA Plant Hardiness Zone Map
- NOAA NCEI U.S. Climate Normals (frost/freeze data)
- NC State Extension Gardener Plant Toolbox, "Liatris"
- NC State Extension Gardener Plant Toolbox, "Liatris spicata"
- University of Wisconsin–Madison Extension, "Liatris"
- UF/IFAS Extension Nassau County, "Fact sheet: Liatris"
- Fairfax County Master Gardeners, "Liatris, a pollinator magnet" (PDF)
- Ask Extension, "Blazing star bulbs: when and how deep?"
Pairings are summarized in our own words from extension-service guidance. Research support for many companion effects is limited, so treat them as good habits, not guarantees.