Liatris spicata grows from a knobbly corm into a tuft of grassy leaves, then in midsummer sends up stiff, feathery spikes of purplish-pink. Oddly for a flower spike, it opens from the tip down, so the top is fully fluffy while the base is still in tight bud. Bees and butterflies arrive as soon as the first florets open.
Native to the damp meadows and prairies of eastern North America, it likes a little more summer moisture than most sun lovers, yet hates sitting wet in winter. This guide explains how to plant the corms, balance that watering, cut spikes for the house, divide clumps and avoid the few problems it has.
Liatris spicata, blazing star at a glance
- Botanical name Liatris spicata
- Common name Blazing star, gayfeather, dense blazing star
- Plant type Herbaceous perennial growing from a corm
- Hardiness RHS H7 (hardy below -20C)
- Height and spread About 60cm to 1m tall, spreading 30 to 45cm, compact 'Kobold' reaches around 40 to 50cm
- Flowering July to September, dense fluffy spikes of purplish-pink flowers that open from the top downwards, white in 'Alba' and 'Floristan Weiss'
- Foliage Narrow, grassy, mid-green leaves in a basal tuft, dying back in autumn
- Position Full sun
- Soil Moist but well-drained, chalk, clay, loam or sand, dislikes waterlogging in winter
- Good for Pollinator borders, prairie-style planting, cut and dried flowers, containers
Corms or pot-grown plants
Dry corms are planted in spring, from March to May, once the worst of the wet has passed. Set them 5 to 8cm deep and 10 to 15cm apart, with the slightly hollow or rough side facing up. If you cannot tell which way is up, plant them on their side and the shoot will find its own way.
Pot-grown plants can go in at any point from spring to early autumn. Plant them at the same depth as in the pot. Groups of five or more look far better than single plants, giving a block of vertical spikes rather than a lonely stem.
Sun and soil that drains in winter
Blazing star needs full sun to stand straight and flower well. In shade the spikes lean and flop, and plants tend to fade away within a few years.
It tolerates most soil types, including clay, as long as the corms do not sit in water from November to March. On heavy ground, add grit to the planting area or plant on a slight mound. Light sandy soils are fine if you add some compost to hold a bit of summer moisture.
Getting the watering right
In summer, liatris appreciates moisture while the spikes are forming. Water new plants weekly in their first season, and give established clumps a deep soak in long dry spells from June to August. Once settled it copes with short droughts, which is why it appears in many lists of drought-tolerant plants.
In winter, do the opposite and let nature handle it. Corms rot if they stay soggy and cold, so never water dormant plants and make sure pots drain freely.
Feeding and keeping the spikes upright
Liatris needs very little feeding. A thin layer of garden compost in spring is enough for border plants, and pot-grown clumps benefit from a balanced liquid feed once a month in early summer.
Rich feeding and shade are the two main reasons spikes topple. In exposed sites the taller forms may need a few twiggy pea sticks pushed in around the clump in May, which the leaves soon hide.
Spikes that open from the top
Most flower spikes, such as foxgloves and delphiniums, open from the bottom up. Liatris works in reverse, which gives it a distinctive candle-flame look as the colour slides down the stem over several weeks.
For the vase, cut stems when the top third of the spike is open. They last well in water and dry beautifully if hung upside down in a warm, airy place, keeping much of their colour.
Wildlife and prairie-style planting
Each spike is packed with small, nectar-rich flowers that draw bumblebees, honeybees and butterflies through late summer. Leave a few spent spikes standing, as the seedheads give some winter structure and seeds for birds.
Liatris looks at home in a naturalistic scheme. Pair it with Echinacea, Rudbeckia, Achillea and grasses such as Panicum or Sporobolus. For a more formal border, its upright form contrasts well with rounded plants like Sedum and Nepeta.
Autumn tidying and dividing
Liatris dies back to its corm in autumn. Clumps slowly enlarge as new corms form, and they benefit from being split every three to four years.
- Cut spent stems to the base after flowering, or leave them for seedheads and cut down in late winter.
- Remove yellowing foliage once it has died back fully in autumn.
- In spring, lift crowded clumps with a fork as the first shoots appear.
- Pull or cut the corms apart, keeping a bud on each piece, and replant at the original depth.
Slugs, rodents and rot
Slugs and snails often nibble the fresh shoots in spring, so protect young clumps as they emerge. Mice and voles sometimes eat dormant corms over winter, particularly in pots and raised beds, and a layer of fine mesh just under the surface helps where this is a problem.
Corms that vanish from a heavy, wet border have usually rotted, so improve drainage before replanting. Liatris is not known to be poisonous, though, as with any garden plant, discourage pets from chewing it.
Questions about Liatris spicata, blazing star
Does liatris come back every year?
Yes, Liatris spicata is a hardy perennial that dies back to its corm each autumn and regrows in spring. It is rated RHS H7, so cold is no problem. Plants are lost mainly through winter waterlogging or rodents eating the corms.
When should I plant liatris corms?
Plant dry corms outdoors from March to May, 5 to 8cm deep in a sunny spot. They usually flower in their first summer, from July onwards. Avoid autumn planting of dry corms, as they can rot in cold, wet soil before rooting.
Why do liatris flowers open from the top down?
It is a natural trait of the genus and unusual among spiky flowers. The topmost florets mature first and the colour gradually works down the spike over several weeks. It means the spike always has a fresh, fluffy section for pollinators.
Can you grow liatris spicata in pots?
Yes, especially compact varieties like 'Kobold'. Use a pot at least 25cm across with a gritty, loam-based compost and good drainage. Water regularly in summer, keep the pot fairly dry and raised on feet in winter, and protect the corms from mice.
If blazing star has earned a spot in your sunny border, browse our perennials collection for liatris and partners that flower alongside it through late summer. All our plants are grown outdoors at Sedum & Sage in Lincolnshire, so they are ready for British conditions.