Does liatris spread in your garden? Yes, but the spread is slow and tame, not pushy like mint or bee balm. This plant forms tidy clumps that grow wider each year through small corm offsets. It will never take over your beds or crowd out the plants near it.
I planted one small corm of dense blazing star in my front bed back in 2020. Five years later, that single plant has grown into a clump about 12 inches wide with seven or eight stems. Two small seedlings popped up a foot away last spring from seeds the parent dropped.
The spread happens in two slow ways that you can watch over time. The corm itself splits and makes small new corms next to the parent each year. These tiny offsets stay close and slowly fill out the clump from the center outward.
Thin fibrous roots hold each corm in place near the soil surface. New offsets sit just 1 to 2 inches from the parent corm and grow up next to it. That is why your clumps stay tight and round instead of running off in all directions like grass.
Penn State Extension notes that liatris spreads from these surface corms and most often liatris self seeding also plays a role in garden settings. Both ways move slow enough that you can let the plant liatris naturalize without worry. You will not wake up to find it taking over your yard one morning.
Seeds drop in fall when the flower spikes dry out and split open on their own. Most seeds fall within a foot or two of the parent plant and sprout the next spring. A few seeds might catch wind and travel farther across your bed.
I find about three or four new seedlings each spring around my main clump in the front yard. You can pull these out if you want a tidy bed or move them to fill in bare spots. Either way, the plant gives you free new clumps for other parts of your garden each year.
When I first noticed those volunteer seedlings, I was worried the plant would spread like crazy. After watching for a few more years, I learned the spread stays slow and easy to control. You can pull or move a few seedlings each spring with no real work at all.
The wide open spaces of a prairie or meadow let liatris liatris naturalize well over many seasons. Drop a packet of seeds in a sunny field and you might see a small colony build up in five or six years. The plant works great for filling in wildflower meadows and pollinator strips.
If you want to slow down liatris clump expansion, divide your clumps every 3 to 4 years in early spring. Lift the whole clump with a fork and pull the corms apart into smaller groups. Replant the best ones and share the extras with your friends.
Cut off the spent flower spikes in late summer if you want to stop self seeding cold. This trick works well in tidy borders where you do not want random seedlings showing up next spring. Or leave the spikes standing for the goldfinches and let your patch grow on its own.
Read the full article: Liatris Plant: Complete Growing Guide
