Cutting Back Perennials Now Means Saving Time In Spring
The following is a regular column that addresses basic issues facing the ever-inquisitive back- and front-yard toiler, proffered by someone who knows best; one of the master gardeners from the Berkshire Botanical Garden in Stockbridge, Brian Cruey.
Now that we have had our first legit freeze, it is time to start cutting back perennials. Yes, you can wait until spring to do this. As a matter of fact, some people even suggest waiting because the amount of plant material you will have in the spring is less (which is true) and you give the plant as much time as possible to photosynthesize.
This just doesn’t work for me. For starters, plant material left through the winter is often viscid and tough (and gross) to cut through. If you have large flowerbeds, it’s also a precarious time to be in your flowerbeds. You don’t want to damage your plants just as they are starting to come up through the spring soil. In the spring I am ready to start anew, my list of things to do is long and the last thing I want to be bothered with is cleaning up last year’s garden.
That doesn’t mean I attack my garden with a weed whacker and start clear-cutting my beds. There are some plants that I intentionally leave through the winter because they provide some benefit. For example, if you have plants that you want to self seed, I would suggest leaving those and letting nature do its thing. On the flip side of that, make sure to cut back those perennials that are over seeding in your garden. Each year I fight back self seeded Japanese Anemone and Black Eyed Susans and that’s even with a good fall cutback. I’m always also sure to cut back my peonies as I always have a few plant that end up with blackened, diseased foliage by the end of the season and I don’t want that lingering in the garden and spreading to other plants next year.
There are other reasons to leave your plants up besides propagation. Many plants have a structure or quality to them that make them a focus of interest in the winter garden. The flower heads of sedum, globe thistle, phlomis, and most ornamental grasses, for instance, look beautiful capped in snow and blowing with the wind. Despite being visually pleasing, many seed heads like sunflower, Echinacea and phlox make excellent food for small birds capable of perching on and eating directly from the plant.
If you are cutting your plants back in the fall, do be careful to wait until you have had a couple of good hard frosts that leave your plants with that obvious “I’m done” look. Cutting back plants too early could actually stimulate new growth on the plant, using up stored resources that it would otherwise use in the spring.
For the most part, when and how you close your perennial beds are a matter of preference. It’s up to you to decide what you want to look at and what you want waiting for you in the spring when the snow melts.