Liatris is a genus of flowers containing over 50 species of flowers, most being pink/purple in color (and very showy). Each species has its own native range within North America, with some overlapping. Liatris flowers are herbaceous perennials, meaning they will die back each year but return the following Spring.
Most members of the Liatris genus prefer full sun and well draining soil. With certain species performing better in semi-moist or dry environments. It is relatively easy to find a species to suit your needs in your garden.
Liatris Seeds and Cold Stratification
Liatris flowers are relatively easy to propagate and grow from seed, if they are not planted too deep and are stratified or winter-sown. The seeds from all Liatris need to go through a winter in order to germinate. So, you will have to either winter-sow the seeds or stratify the in the refrigerator in order to get a high germination percentage. You can learn a few ways to cold stratify seeds by clicking here.
I’ve generated the table below to show how many days are recommended for cold stratification. If you winter sow you can disregard this table (as long as it gets down to the 30’s at night). Just make sure you winter sow by January. Now, most of the number of stratification days come from seed companies. Based on the studies I quoted above, I would suggest you winter sow your seeds, and do it by January. It seems clear that the highest germination percentages will occur with longer stratification times. And you will get that with late Fall/ Early Winter sowing of seed. Besides, that is how mother nature plants these seeds, and why shouldn’t you do the same?
You can approach this one of two ways. The first method (my preferred) is just to winter sow the plants. You just plant them as you normally would, but keep them in a covered plastic container, or dome with holes poked in for air movement. Then, just place the seeds outside, and voila.
The other way to cold stratify seeds is to simulate the cold/moist winter by placing them in the refrigerator. To do this, either mix the seed with moist sand in a bag. Or you can use a moist paper towel.
Fill pots with moist potting soil, to about 1/2″ (12 mm) below the top of the pot. Your soil should be moist, and it is easiest to moisten it in a bucket before putting it into the pot. However, you can easily do it if you spray water as you add soil to the pot. You don’t want the soil sopping wet, just moist.
Place 3-5 seeds in each pot or cell. Press them firmly into the dirt.
Lightly cover the seeds with with just a dusting of soil, no more than 1/16″ deep (<1 mm)
Take a few more seeds, and press firmly into the moist soil. Do this so they are exposed from the top, but have good contact with the soil everywhere else.
Mist the seeds with a spray bottle, or pump sprayer – taking care not to wash everything out.
Place seeds in an area where they will receive morning sun, and keep moist.
Germination should occur once temperatures are reliably above 50F at night (if winter sown). Otherwise, you should expect seedlings within two weeks (if stratified in the refrigerator).
Finally, you need to care for the seedlings until they are several inches high. Finally transplanting them into their final location.
Note! Rabbits do love to eat young Liatris Plants. Consider protecting them with Liquid Fence or chicken wire the first year (at least).
Here is a short video I made some years ago on how I plant my seeds – hope you enjoy!
Some notes about watering, and how moist should ‘moist soil’ be
When I am germinating any seed, I generally water them in the mornings before I go to work. When the forecast calls for sunny days or hot weather, I will spray water on them until the soil is black/moist, and the pot feels heavy. That way I know I have water throughout the entire depth of soil inside the pot.
When I return in the afternoon, I will check to see if they need to be watered again. If the pot feels light weight, or the top of the soil is very dry I will add more water via a pump sprayer until the pot feels somewhat ‘heavy’. I will continue this these two processes until germination.
Once the seeds have germinated, and I have seedlings I will avoid watering in the afternoon, and almost never water at night. The reason I avoid this is because of something called damp-off disease. Damp-off disease is a fungus that can weaken the stems and kill the young seedling. So, to avoid this it is best to not have the seedling sit in fully saturated soil overnight.
How and When to Transplant Liatris
Once your seedlings have grown to be 3-4″ tall, they are more than ready to be placed into their final location.
Dig a hole to just below the depth of the pot, and twice as wide.
Put a handful of compost at the bottom of the hole, and gently mix it in.
Water the hole, and wait for the water to drain.
Plant your Liatris, filling in around the pot. Pack soil firmly.
Protect your seedling. Apply liquid fence (it really works) or put some fence around the plant and stake it.
You can transplant your seedlings in the summer – just know that it may require supplemental water for several weeks if it is in an area prone to drought. You can plant your seedling as late as nature lets you! So, even if it is in December, if the ground isn’t frozen you can plant the plant. The roots will still grow just fine and establish themselves, even if it is cold temperatures above ground.
How long does it take to grow Liatris from Seed?
Generally, Liatris will not flower until it’s second year after seed germination. Liatris is a large perennial that requires significant root/corm development. Typically you won’t have any flowers the first year. It will just look like a large, leafy plant on the ground. In the rare case where you do get a bloom, it will generally be a single stalk/flower. And it will occur much later in the year than Liatris’s normal bloom time. But – the second year of life for Liatris will produce some blooms. And in the 3rd year of life, you will be treated to a massive display if planted in the flower’s preferred conditions of full sun and well drained soil. And after the 3rd year, you should consider dividing your Liatris plants to keep them looking healthy and vigorous.
Is Liatris Difficult to Grow from Seed?
Liatris can be a little tricky to germinate from seed. This primarily arises from people being unfamiliar with, or not performing a cold stratification/winter sowing of Liatris Seed. Also, there are some references out there that tell you to plant the seeds deep, when you should really only lightly plant them. Surface sowing to just under the surface of soil is the proper depth for planting Liatris Seeds.
Hi - I grew up outdoors in nature - hiking, fishing, hunting. In high school I got my first job at a garden center where I learned to garden and landscape. I've been growing plants from seed and designing native plant gardens for over six years. I hope to share some of my knowledge with you!
Additionally I am a wood worker / DIY enthusiast. I enjoy designing/building projects (with hand tools when I can!). I hope to give you some tips and useful information!