|We live in zone 4, which actually borders on zone 5; when and what do I do to prepare my Kansas Gayfeather (liatris spicata 'floristan violett') for winter?
|In my garden I leave the foliage on perennials until the frost kills them back, i.e., they wither and brown. It is important to leave the foliage intact while it is still green so the root system can store up enough food energy for the long hibernation. I then cut them back to a height of 3". Mulching is not necessary, but if you wish to do so, apply a light, airy mulch such as pine boughs after the ground freezes.