Several of you have messaged me asking, “when do I trim my perennials back?” That’s a subjective question, but through the years, I’ve realized that it’s not “when” but “how” is the more important question.
Last year, I trimmed back my perennials at our first cold snap in the early part of November, Unbeknonst to me, we had a warm December, so all my perennials that I had already cut way back were urged to resprout and even bloom again. Then we had that unusual snow for several days which I thought would for sure kill my itty bitty poppies and larkspur that had already sprouted and my butterfly bush and turk’s cap who had thought it was spring and shot out strong, new, green branches! But guess what? when the snow thawed, all this new growth was just fine and cam on even stronger in early March like they’re supposed to.
Therefore, my conclusion is, cut back your perennials whenever you have time to. The important procedure in cutting back is to mulch heavily, about 5 inches is best. I call this putting my babies to bed and tucking them in for the winter, no matter how crazy our weather gets.
1. Herbs: Those herbs that spread by roots like oregano and mint, cut back to the ground and cover with light weight mulch like leaves. Tri-annuals like parsley and sorrel, cut back leaving about 3 inch stubs and cover heavily with mulch. With chives, I let them fall over and freeze. Their wilted tops serve as mulch. Woody herbs like Rosemary and thyme are best left as is just shaping the tops and cutting back the interior woodiness, but definitely mulch heavily as well.
2. For flowering shrubs like lantana, plumbago, and turk’s cap, cut back to the ground after the first hard freeze, and mulch heavily.
3. For roses, cut back in February by 3/4, trim out the dead woody stalks and mulch around the base.
4. For vines like jasmine and passion flower, wait till after the first freeze and cut back to the ground.
5. Clumping flowering perennials like shastas, echanashias, phlox, and coreopsis can be trimmed back to the ground leaving some greenery and seed stalks for the birds. Mulch heavily because they spread by clumps underground.
Clean your cutters, clippers, and pruners with alcohol between plants to deter transferring any disease from plant to plant. Store your hand tools blade sides down in sand mix with mineral oil to keep blades clean and rust free.
How have you cleaned up your winter garden?
I prefer winter and fall, when you feel the bone structure of the landscape – the loneliness of it, the dead feeling of winter. Something waits beneath it, the whole story doesn’t show.