Foliage and football might be two things people instantly associate with fall, but this beloved season isn’t all about brightly colored leaves and action on the grill.
Gardeners know spring is a great time to plan and plant their favorite flowers and the tastiest fruits and vegetables. However, seasoned gardeners know that gardening is a year round commitment. Pruning is one of the keys to keeping perennials coming back for years to come, and fall is a great time to take on this important task.
Pruning perennials in the fall is not a one-size-fits-all endeavor. According to the Old Farmer’s Almanac, some perennials can be cut after the first killing frost, while others can be left for the benefit of wildlife, including birds and insects. Understanding the size and when to do it this fall can help gardeners lay a solid foundation for their gardens, which will benefit them next spring.
Why prune certain perennials?
The College of Agricultural Sciences at Pennsylvania State University notes that perennials that have become diseased or infested with insects are pruned to prevent these problems from resurfacing in the spring. Additionally, according to the Old Farmer’s Almanac, many herbaceous perennials have old foliage and dying stems after several severe frosts. If dead foliage or dying stems are not pruned, diseases, slugs, and other pests can overwinter in plants. Cutting these plants back to the ground after several hard frosts allows the base of the plant to remain dormant through the winter, but makes it less hospitable to disease and insects.
Which perennials should I prune?
The first step in pruning perennials is recognizing which ones need to be pruned and which ones can be left untouched for the winter. The Old Farmer’s Almanac notes that bee balm and phlox are prone to powdery mildew and should be reduced once they are gone. Hostas are home to slug eggs, so they also need to be pruned after a heavy frost. Hosta leaves that have fallen to the ground should also be removed. It is not necessary to cut some perennials if they are healthy. For example, hardy geraniums don’t require pruning in the fall, and Penn State Extension notes that hardy perennials like garden mums are more likely to survive a cold winter if left untouched. This is because the tops of these plants will collect leaves and snow for insulation and moisture during the winter. Gardeners who are unsure of fall pruning can speak to their local garden center for additional advice on plants to cut before winter.
Gardeners don’t have to rush to prune perennials in the fall. Sick or infested plants can be pruned at the first appearance of a disease or infestation, but gardeners can wait until several hard frosts have occurred before pruning healthy perennials. In gardening jargon, a hard frost refers to a temperature below 28 Â° F. Several hard frosts kill the highest growth of most perennials, making this a great time to prune them.