Grow Liatris from Seed
You’ll be happy to know that you can grow Liatris from seed rather easily. Liatris flowers are very unique. Tall spikes of bright purple bottlebrushes above tufts of green, grass-like leaves in late summer. Very attractive to butterflies, bees, and other insects.
Grow Liatris from Seed: Collecting Seeds
Liatris is a North American prairie native but commonly growing in perennial gardens. The showy plant is known to be very hardy and does well in most soil types, even clay soil.
The tall spikes of the Liatris consists of dozens of individual flower buds clustered together covering the entire stalk. The blossoms open from top to bottom producing a bottlebrush type of flower.
When the flower begins to die off, they start to turn brown from top to bottom as you can see in the photo below. To ensure that you get the most viable seeds possible it’s best to wait until the entire flower spike has turned brown and completely dried out.
The seeds of the Liatris have a feathery pappus and a conical shaped seed less than 1/16″ in diameter and about 5/16″ long. I found it’s easier to gather the seeds if you leave the stalk attached to the plant. With your forefinger and thumb encircling the stalk begin stripping the feathery chaff off the stalk from bottom to top leaving behind only the center core of the stalk. It’s best to use a paper bag and left the chaff fall into the bag as you strip it, there will be a lot of it from each flower stalk. You may want to wear gloves when doing this to prevent cuts from the grass like leaves.
Once you’ve stripped the stalks you may want to separate out the seeds for planting indoors or you can save seeds and chaff together if you’re planning to direct sow outdoors.
When separating the chaff, I found that many of the pappus appeared to have a seed attached but many of the seed heads were hollow and did not contain a viable seed. Luckily it is very easy to determine which seeds are viable because they feel solid when a fingernail is pressed into them, not too hard. I’d say that only about 25% of the seed heads contained a viable seed.
Sow Liatris Indoors or Outdoors
Liatris can either be direct sown in the garden or started indoors. I’ve never tried to direct sow Liatris outdoors but my experience with starting the seeds indoors resulted in almost a germination rate of almost 100% after ensuring I had saved only the viable seeds.
Grow Liatris from Seed Outdoors: Direct Sowing
If you choose to direct sow the Liatris then, as I mentioned earlier, there’s really no need to separate the seeds from the chaff. Just simply choose your planting area and spread the chaff seed mix in your desired location and lightly cover with soil just before the first snowfall.
Grow Liatris from Seed Indoors: Containers
When starting seeds indoors always use a good sterile seed starting mix for the best results. I use Burpee Organic Seed Starting Mix; it’s made of coconut coir and perlite. Another good soil is Espoma Seed Starting Mix.
It has been said that you should submit the seeds of the Liatris to a stratification period of cold by placing them in a refrigerator for a couple months but I never do this and have excellent germination rates. First, you’ll need to fill your desire container with damp, but not overly wet, seed starting mix. I prefer to use a six-cell seed pack to start all my perennial seedlings then transfer to larger containers with a potting soil once the seedlings are large enough.
To grow Liatris from seed use a planting depth of no more than 1/4″ deep. I usually put two seeds separated in each of the cells of the seed trays. From my experience it didn’t make a difference to lay the seeds flat in the holes or spike them into the soil. Once you’ve sown the seeds place the container in a humidity dome and place it in a warm area such as the top of your refrigerator or on a seed warming mat. If you use a seed warming mat set the temperature to about 75F. Germination time for me has been around 7-10 days even in my basement at around 65F.
Once the Liatris seeds sprout you’ll notice that, like most seedlings, the cotyledons look very different. The foliage of the mature Liatris plant is very grass like but the cotyledons are small and rounded. It will only take about a week before you see the first slender leaves of the Liatris seedling emerging, the first true leaves. The Liatris seedlings with true leaves you see in the photos above are about 2-3 weeks old. Once the seedlings are large enough you can transfer them to a large container with potting soil.
Did you know we sell Liatris Seeds?
Propagation By Dividing Liatris
Another method to increase the amount of Liatris flowers in your garden is by dividing. Liatris flowers arise from a cluster of corms (rhizomes). Each corm will send up one flower stalk so if you plan on dividing your Liatris it’s best to make sure it is several years old and produce several flower stalks from the base each summer.
How To Divide Liatris
The ideal time to divide Liatris is spring once the leaves of the plant start emerging. Using a spade, you’ll want to dig around the corms of the Liatris and then slide the shovel beneath the clump and lift it out of the hole.
Once you have the cluster of rhizomes (corms) out of the hole you’ll want to use some water to rinse them off to help visualize where to divide. Use a knife as needed to separate the corms. Make sure each piece (corm) has roots and a starting shoot.
The separate corms can be planted in the location of your choice. Plant the newly separated corms with the new green shoot at the same depth they were when you dug them up. It would also be beneficial to add a little fresh compost to the planting holes. A common method of planting the corms is to place them in a starburst configuration which will grow into a nice stand of flowers. Splitting the Liatris corms every few years not only multiplies the amount of the beautiful tall bottlebrush flowers in your garden but is also healthy for your Liatris.