A well-planned perennial garden can look beautiful when first planted, but if you fail to properly maintain your perennials with proper pruning, your garden may not look as impressive as the years go by. If you want to keep your perennials thriving, proper pruning is essential. Knowing the difference between annuals and perennials, as well as which perennials need pruning during the spring or fall, will help you plan the proper care.
It may look as though your perennials have died when the first frost hits, but this isn’t always the case. Annuals will usually die from the harsh winter weather and will need to be pulled out of the ground in the fall, but perennials have simply gone dormant and moved their resources underground, storing energy to return in the spring. Annuals are intended to only grow for one season, but perennials, with proper care, will come back year after year.
In the fall, you cut back perennials to clean-up, and to rejuvenate and re-seed certain perennials. ‘Perennials’ that may need to be re-seeded in fall are Monarda (bee balm), Penstemon (beard tongue), and Tall Phlox.
The main reasons to prune perennials in fall would be to prevent them suffering fungal disease or from being devoured by pests. Also, some perennials not cut back in the fall can turn soft and slimy after fall frosts, proliferating pests, and disease. Perennials you should cut back in fall include Peonies, Daylilies, Hosta, Catmint, Hollyhock, and Rocket plant.
Other perennial plants can create visual interest or food and habitat for wildlife during the dormant season, and if healthy they can be left alone. Overall, pruning as part of your fall clean-up will keep your garden beds healthy, clean, neat, and tidy.
In spring, old foliage should be removed from any perennials that were not pruned back in fall. Some perennials will thrive with a cut-back at the beginning of the growing season. The spent stems and browned leaves of Sedum, Bear’s breeches, Chrysanthemums, Echinacea (Purple Coneflower,) Japanese Anemone, Verbena, and Ornamental grasses will do well with spring pruning.
Perennial plants which bloom during summer and fall should also be pruned in spring to create bushier, more floriferous plants. Clearing beds for the coming season will make them neat and tidy, clean out any overwintered pests or diseases for healthier plants, and will stimulate new growth.
Whether you cut back your perennials in the spring or the fall, it’s important to do it properly. A hand pruner and a spray bottle of rubbing alcohol or disinfectant are all you need.
Trim at a slight angle, leaving at least 3 to 6 inches growth in fall, and being sure to remove any diseased or pest infested plant material.
In spring, cut 3 to 6 inches above new growth; or 6 to 8 inches above ground for larger perennials and warm season grasses.
Spraying or wiping the pruners in between cuts will sterilize them and prevent any transmission of fungus or infection.
Removing spent flowers during the growing season will stimulate re-blooming and prevent plants from using their energy on seed production. If perennials (and annuals by the way) are consistently deadheaded while they are blooming, their season can be extended, and your garden will look much healthier. Spent flowers not only look bad but can be a breeding ground for insects or disease.
The first step in proper pruning is knowing which plants you have in your garden and what their needs are! If you need help in determining how to care for your garden, contact Twin Oaks Landscape to assist you with all your garden and landscaping needs. With the right care, you can have a perennial garden that thrives year after year.