When choosing between liatris sun or shade, pick sun every single time you can. This native plant craves bright direct light for at least 6 hours each day. Skimp on sun and you will end up with weak floppy stems that need staking just to stand up.
The liatris light requirements point clear and strong to wide open sunny spots in your yard. I learned this lesson the hard way when I split a single batch of corms between two beds in my garden two years back. One bed got full sun while the other only got morning rays.
The sunny bed gave me thick stems and tall purple spikes that stood up to wind and rain. The shadier bed had weak floppy growth that fell over by mid-July. The blooms came in smaller and faded much faster than the sunny ones.
The reason traces back to where these plants come from in the wild. Liatris grew up on open prairies with full sun beating down all day long. The plant did not evolve to deal with shade from tall trees or buildings nearby.
Full sun liatris plants build thick sturdy stems that hold up tall flower spikes through summer storms. The dense root system also gets stronger when the plant gets all the light it needs to make food. That is why your sunny clumps live longer and bloom harder each year.
UF/IFAS Extension lists liatris as a full sun plant that needs bright direct light to thrive. Penn State Extension also calls it a sun-loving rain garden plant that handles open exposed sites well. Both sources back up what I see in my own beds each summer.
Some folks ask about liatris partial shade when they only have spots with mixed light to work with. The plant will live in dappled shade or with 4 hours of direct sun, but it will not look its best for you. Expect taller floppy stems and fewer flower spikes per clump.
If you must plant in part shade, choose the brightest spot you can find with strong morning sun. Skip the deep shade under big maples or oaks where less than three hours of sun reach the ground. Those spots will kill your clumps within two or three years.
Look for a spot in your yard that gets 6 to 8 hours of direct sun each day with no big trees blocking the light. South-facing slopes and open meadow edges work best for strong tall blooms. West-facing borders along a fence or wall also give you the bright light these plants crave.
Stick to bright open spots and you will get straight tall spikes that stand up on their own without stakes. Your liatris will reward you with bigger blooms and more of them each summer when you give them all the sun they want.
Read the full article: Liatris Plant: Complete Growing Guide
