If a person were to take a look at my flowerbeds, they would immediately know that perennials are my absolute favorite. My beds are loaded with grasses, evergreens, groundcovers and flowers. I especially like the fact that many of them reproduce and spread, which gives me the opportunity to share my bounty of perennials with others.
I like to leave my perennials standing during the winter months rather than cutting them down. Some perennials have attractive foliage or rather what is left of it after the cold weather has set in. Some also have seed heads that are a source of food for birds and stems that give them a place to hide when a predator is lurking about. For some marginally hardy plants, leaving the stems aids in their overwintering. To help insulate the crowns of my chrysanthemums, I leave the stems standing and pack them with leaves. If a perennial is a late riser in the spring, leaving the stems on will alert a person to not dig at that spot and harm the underground portion of it.
There are some instances where you will want to cut back a perennial as in the case of a foliage disease. Diseased foliage should be removed to reduce the amount of reinfestation to the plant during the next growing season. If cutting is necessary or preferred, it should be done after the plant has gone dormant. This usually happens after a few hard frosts. When cutting, leave about two to three inches of the plant. Do not cut back to the soil as this can result in injury to the plant due to the fact that in some perennials, next year’s buds are right at the surface or a bit higher and not below the soil line.
If you have done some late fall plantings of perennials I would recommend that they be mulched very well to prevent frost heaving and the chance that they will not survive the winter. I generally like to place about two to three inches of mulch around a late planting.
As always, Happy Gardening!