“Dabney! No! Wait!” Just kidding. Dabney Blanton, our lovely and talented horticulturist, knows not to prune the Artemisia in the autumn.
I imagine most gardeners have experienced a frost or freeze by now [exceptions: our Southern Hemisphere readers (howdy to Jimbo)…or anyone in the deeeeep south].
The perennials here in Blacksburg have taken a couple of hits; time to start trimming things back. In the Hahn Horticulture Garden and in my own personal garden, we like to leave perennials and ornamental grasses up as long as possible – gives us something to look at besides mulch, plus the wee birdies enjoy it.
But some perennials just look yucky after a freeze.
Case in point: foliage of the popular perennial Artemisia ‘Powis Castle’ resembles graying Kleenexes, hanging on the tips of the branches. HOWEVER, do not cut this back in the fall. It, like many other shrubby perennials, is sensitive to early winter whacking, in my experience, Buddleia and Caryopteris also fall into this category. Apparently the severe pruning sends a message to the plant to break bud – new shoots can appear and then “zap!” Wait until new buds appear in the spring, and be careful not to cut back too hard. I’ve killed a few that way, thinking I was doing them a favor.
“Cut ‘em back, cut ‘em back, waaaaay back!”
The best resource ever on maintaining perennials is Tracy DiSabato-Aust’s The Well-tended Perennial Garden. I should get kickbacks, as much as I’ve promoted this book! Truly a wealth of info – when should you cut it back, will it rebloom if deadheaded, don’t do [whatever] or you’ll kill it – all broken out by genus. Outstanding!