How to Grow Liatris: The Top-Down Spike

Liatris is an easy, hardy perennial with fluffy purple or white spikes in late summer. It grows from a corm planted in spring, and needs just two things: full sun and soil that doesn’t stay wet in winter. Get those right and it comes back bigger every year.

Its party trick is the way it flowers. Most spikes open from the bottom up, but liatris opens from the top down. This guide covers which type to grow, how and when to plant, and how to stop the corms rotting. Liatris suits prairie borders, gravel gardens, cutting patches and sunny pots.

What is liatris?

Liatris spicata is a hardy perennial from the prairies and grasslands of eastern North America. In the UK it’s called blazing star or gayfeather. It grows from a rounded, knobbly storage organ called a corm. Our guide to bulbs, corms, tubers and rhizomes explains the difference.

In spring each corm sends up a tuft of narrow, grassy leaves. Then come stiff flower stems covered in small, feathery flowers. Because they open from the top down, each spike looks neat for weeks, and a clump flowers across July, August and September.

Liatris opens from the top down. Here the tip is in full flower while the lower buds wait their turn.

Which liatris should you grow?

Most garden liatris grows 40-90cm tall. For a first try, start with ‘Kobold’ (sometimes sold as ‘Goblin’). It’s short and sturdy, and rarely flops.

The ‘Floristan’ pair are tall, straight cutting types that are happier with a stake. Liatris pycnostachya, the prairie blazing star, is a showstopper for butterflies, but it’s top-heavy and needs good support. If your garden is cold and wet, stick with ‘Kobold’ or ‘Floristan’ and improve the drainage first.

When and how to plant liatris corms

Plant liatris corms in March or April, once the soil starts to warm. Don’t plant in autumn. A corm sitting in cold, wet soil all winter often rots before it grows.

Choose a spot in full sun with free-draining soil. Plant each corm 5-10cm deep and 10-15cm apart. Put the side with small buds or an old stem scar on top. If you can’t tell which way up it goes, plant it on its side and it will sort itself out. Groups of five or more look far better than singles.

Water once to settle the soil, then let spring rain take over. Leaves usually appear a few weeks later. Liatris looks lovely in a naturalistic prairie-style border with grasses and echinacea.

Plant corms in spring into gritty, free-draining soil. Good drainage now is what carries them through winter.

Gardener’s tip: Choose plump, firm corms. Small, shrivelled ones often sulk for a year. Plant any soft or very light ones in a spare corner where a gap won’t matter.

Why liatris rots in wet clay, and how to stop it

The usual way to lose liatris isn’t frost. It’s winter wet. A dormant corm sitting in cold, waterlogged clay from November to March rots from the base. The same corm kept fairly dry takes hard frost without trouble.

Wet clay, not cold, rots liatris corms. The firm one came from a gritty, well-drained bed.

Heavy clay holds water around the corm for months. Planting a bag of corms straight into a clay border and hoping for the best often ends with gaps the next spring.

The fix is drainage, done once. Fork plenty of horticultural grit into the bed, or build a raised bed with grit mixed in. On a really wet site, grow liatris in pots. Our guide to improving clay soil shows how to open up heavy ground for good.

Growing liatris in pots and gravel

Pots solve the drainage problem straight away. Use a 25-30cm pot with a big drainage hole. Fill it with two parts peat-free multipurpose compost to one part grit. Plant three to five corms about 8cm deep and stand the pot in your sunniest spot. Never leave it in a saucer of water.

Feed pots lightly, once in late spring at most. Refresh the top layer of compost each spring and split the clump every few years as it fills the pot.

A sunny gravel bed suits liatris well too. The lean, fast-draining ground keeps the corms dry in winter and the stems short and sturdy.

Compact ‘Kobold’ is perfect for a gravel bed. Lean, fast-draining ground keeps its short stems standing straight.

Feeding and staking liatris

Grow liatris lean. It comes from poor prairie soil, and rich, nitrogen-heavy ground makes soft, tall stems that flop in the first summer storm. Most gardens need no feeding at all. On very poor soil, one light low-nitrogen feed in late spring is plenty.

Short varieties like ‘Kobold’ stand on their own. Taller ‘Floristan’ types and L. pycnostachya need support by June. Push in twiggy sticks or a ring support while the stems are still short, so the plants grow up through it. Our guide to staking tall perennials shows a few neat methods.

Slugs and snails love the soft new shoots from March to May. Check after damp evenings until the leaves toughen up. Our guide to getting rid of slugs covers safe ways to protect them.

Liatris for bees and butterflies

Liatris is one of the best late-summer nectar plants you can grow. Each spike is packed with tiny flowers, so a single stem feeds insects for weeks. On warm August afternoons the spikes fill with bumblebees, honeybees and butterflies. Plant it with scabious, echinacea and verbena for a big block of late nectar. Our list of the best plants for butterflies has more ideas.

A red admiral feeding on liatris in late summer. Butterflies love the long, nectar-packed spikes.

Liatris as a cut flower

Liatris makes a long-lasting cut flower. Cut the stem when the top third of the spike has opened. Strip the lower leaves and change the water every couple of days. Because it opens from the top down, a cut spike keeps looking good long after others fade.

Cut stems when the top third of the spike is open. They keep looking good in a vase for ages.

The tall ‘Floristan’ types give the longest, straightest stems. They pair well with scabious in a cutting patch.

Dividing liatris and leaving seedheads

Liatris clumps get bigger over time, which means free plants. Every three or four years, lift a crowded clump in early spring as growth begins. Pull or cut the corms apart, keeping a bud and some root on each piece. Replant them 10-15cm apart in well-drained soil.

You don’t need to lift liatris for winter. Leave the corms in the ground, as long as it drains well.

You can also leave some spent spikes standing in autumn. They add shape to a winter border, and seed-eating birds sometimes visit them. Cut them back in late winter before new growth starts. Liatris can also be grown from seed sown in autumn, but expect to wait two or three years for flowers.

Leaving a few faded spikes standing adds winter structure, and seed-eating birds may drop by.

Liatris growing calendar

Common mistakes with liatris

Planting in autumn. Autumn-planted corms sit cold and wet for months and often rot. Plant in March or April.

Planting straight into wet clay. Waterlogged winter clay kills far more liatris than cold. Add grit, use a raised bed or grow in pots.

Feeding too much. Fresh manure and high-nitrogen feeds make soft stems that flop. Grow it lean.

Growing it in shade. In shade it stretches, leans and makes few spikes. Give it full sun.

Leaving tall types unstaked. ‘Floristan’ and L. pycnostachya can snap or flop in summer storms. Support them by June.

Frequently asked questions

How do you grow liatris in the UK?

Plant corms in spring in full sun and free-draining soil. Set them 5-10cm deep and 10-15cm apart. Water in once, then leave them. Stake tall types. On heavy clay, add grit or use a raised bed to stop winter rot.

Is liatris hardy in the UK?

Yes, liatris is very hardy and copes with UK frosts. Cold rarely kills it. The real danger is a corm sitting in cold, waterlogged clay over winter, which makes it rot. Good drainage matters far more than frost protection.

When do you plant liatris corms?

Plant liatris corms in March or April. Wait until the soil starts to warm. Autumn planting leaves the corms sitting cold and wet for months, and they often rot. Keep bought corms cool and dry until planting.

Does liatris flower the first year?

Yes, a spring-planted corm usually flowers in its first summer. Spikes appear from July. The clump then gets bigger and flowers more each year. Plump, firm corms give the best first-year show.

Why is my liatris flopping over?

Usually too much feed or too little sun. Rich, freshly manured soil makes soft stems that keel over. In shade the plant stretches and leans. Grow it lean, in full sun, and stake taller varieties early. ‘Kobold’ rarely needs support.

Is liatris good for bees and butterflies?

Yes, it’s a great late-summer nectar plant. The dense spikes feed bumblebees, honeybees and butterflies through July and August. Plant it in a group for the biggest buzz.

Does liatris come back every year?

Yes, it’s a hardy perennial that returns each year. It dies back in autumn, rests over winter and reshoots in spring. If it doesn’t come back, the usual reason is the corm rotting in wet soil.

Can you grow liatris as a cut flower?

Yes, it’s an excellent cut flower that lasts well in a vase. Cut stems when the top third of the spike has opened. Strip the lower leaves and change the water every couple of days.

Now your liatris is planted, find more summer colour in our flowers and plants hub, or plan a whole patch with our guide to growing cut flowers.