Some perennials, like hostas, peonies and daylilies, need to be pruned in fall to avoid winter damage. Plants like these should be pruned after the first few frosts in late fall or early winter. Other perennials like mums and coneflowers are better off being pruned in spring just before new growth comes in.
Also, do not cut back hardy perennials like garden mums (Chrysanthemum spp.), anise hyssop (Agastache foeniculum), red-hot poker (Kniphofia uvaria), and Montauk daisy (Nipponanthemum nipponicum). Leave the foliage. It's important to protect the root crowns over winter.
It's common to think that everything should be chopped down to the ground in the fall, but some perennials actually need their foliage to protect new shoots through the winter. Other varieties offer up important habitat for local wildlife and some perennials provide height and interest through the winter months.
Many gardeners cut back their perennials much too soon. There are nuances specific to certain perennials that dictate whether it is better to cut them back in fall or spring, but the general rule I like to follow is to only cut back perennials that start looking bad in fall.
Q: When is the best time to cut back in the fall? A: “When they start to look too ratty for you and before the fresh new growth begins,” says Sarah. For plants that are frost-sensitive, wait until after the plants have gone through several hard frosts to ensure they're dormant before cutting back.
Some perennials, like hostas, peonies and daylilies, need to be pruned in fall to avoid winter damage. Plants like these should be pruned after the first few frosts in late fall or early winter. Other perennials like mums and coneflowers are better off being pruned in spring just before new growth comes in.
Cutting back perennials in the fall is not only a great way to keep flowerbeds looking neat and tidy through winter, but it also aids greatly in keeping plants vibrant and blooming the following year. Removing spent foliage and blooms helps a plant focus on recharging it's roots and resources.
The good news is that hostas, also known as plantain lilies, are tough and forgiving plants. Even if you forget to prune them at a certain time or you neglect to prune them at all, they'll still survive just fine, even if they don't look their best.
Divide fall blooming perennials in the spring because
Plants have stored up energy in their roots that will aid in their recovery. Rain showers that generally come along with the early season are helpful. Plants divided in spring have the entire growing season to recover before winter.
Daylilies are best cut back in autumn, once the leaves have had a full growing season on the plant. While there are some evergreen types of daylilies, most are herbaceous, meaning that the leaves die back in the wintertime and sprout anew in the early spring.
Any gardening expert will tell you, (contrary to what you may believe) that pruning encourages new growth just when the plant is trying to go dormant and new growth doesn't have enough time to harden before the first frost and freezing temperatures hit. Pruning at this time of year will severely weaken the plants.
As a general rule, prune spring-blooming trees immediately after they flower. Prune trees that bloom in the summer or fall in late winter or early spring before the end of their dormancy. Routine pruning of dead or dying branches can be done at any time.
Don't shear the branches of spring flowering shrubs (Forsythia, Lilac, New Mexico Privet, Spirea, Flowering Quince, and others). These shrubs produce flowers on last year's wood, so removing old growth will reduce or prevent flowering. These plants should be pruned immediately after they are done blooming.
As a general rule, hostas should be cut back in the late fall. Start with leaves that have wilted or turned brown. Healthy leaves can stay a bit longer to help the roots store needed energy. If 25% or more of the hostas is dying, you will know it is time to cut it back.
It's important to cut back foliage in the fall to protect flowering plants from disease and give them a clean start for regrowth as winter starts to turn into spring. However, there are some plants you can keep around through the winter since they benefit wildlife and still offer visual interest for your home.
By dividing the plant when it is not flowering, all the plant's energy can go to root and leaf growth. Fall division should take place between early September in the uppermost Piedmont and mid- to late October on the coast. Allow at least four to six weeks before the ground freezes for the plants to become established.
Never shear a shrub in fall (or ever, actually, but that's another article) and leave major pruning or renovation for late winter/early spring, or immediately after bloom for spring-flowering shrubs.
2. Perennials and shrubs that are in your zone or one colder can be overwintered in an unheated garage, buried in the ground, or transplanted. 3. Perennials and shrubs in containers will need water through the winter but should not be kept wet.
Cutting back of dead or dying top growth is the only maintenance that is needed for winter preparation. Cut the stems down to the ground, or to the basal growth if you are gardening in the warmer hardiness zones. Alternatively, the flower stems can be left to cut back in the spring.
Some perennials benefit largely from regular pruning during the summer growing season, but the most important cleanups are in the fall and the spring. A host of perennials respond best to a tidy spring cleaning and are seemingly rejuvenated from the practice.