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.
Cut the bloom's stem to less than 2 inches. Carefully stick the bloom in the sand and gently cover it. Put the bowl in a cool, dark place like a basement or garage. It will take about four weeks for this process.
1) Empty out the dead flowers, roots, and used potting soil.
Compost bags are often available in the fall at local hardware stores. The trash bag is for dead plants that looked diseased. Throw away any plants that looked diseased at the end of the growing season, as well as all the potting soil from that flowerpot.
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.
Spring flowering shrubs and trees.
Shrubs and trees like lilacs, azaleas, and others will grow best when they are pruned right after they flower in the spring. Avoid pruning them in the winter as it may stunt their growth.
Apply hay or mulch to insulate plants.
This measure holds in both heat and moisture to protect root systems. Water jugs filled with warm water and placed in the mulch provide even more protection from the cold.
During the growing season, the plant stores energy in its roots, bulb or corm (aka rhizome)—the part where the stem and root meet). That energy allows it to go dormant in the winter, much like an animal might hibernate. When conditions like temperature are right the next spring, the plant begins to grow again.
Freezing temperatures don't harm dormant plants. However, freezing temperatures can damage new spring growth, especially flowers. As flower buds begin to swell, they become increasingly vulnerable to cold temperatures. They are most vulnerable just before, during, and after bloom.
They just do not like any temperature below freezing. Don't get me wrong flowers like it cold. Flowers are happiest in temperatures of 40-50 degrees. Most of my flower coolers are about 36 degrees.
Prune most broadleaf evergreens now: abelia, boxwood, cleyera, elaeagnus, nandina, privet, and holly. Wait until after flowering for spring bloomers. Viburnums (both evergreen and deciduous) can be cut back hard to reduce size, but you will sacrifice flowers for the season.
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.
But when should hostas be cut back? Hostas should be cut back in late fall. Healthy hosta leaves can be left on the plant in early fall to capture much-needed energy, but all leaves should be trimmed off after the first frost to deter slugs and other pests from making your hosta their winter home.
Bury the pots or bring them inside.
Simply dig a hole and plant the perennial pot and all. This way the soil in the pot will benefit from the temperature-stabilizing mass of the ground soil. Alternatively, bring the pot into an unheated, not-too-bright interior space, such as a garage or cold cellar.
Most trees should be pruned during the late dormant season (February through March). February through March is generally regarded as the best time to prune most deciduous trees.
Late fall is the best time to winterize perennial plants. A hard frost can be the signal to prep the beds for winter. If below-freezing temperatures are forecasted overnight, or you wake up to frost on the ground, it's likely a good idea to winterize your perennials within the next few weeks.
If your flowers or leaves have spots, mold, or fungus, go ahead and discard them in the trash bag. You'll also want to throw out the soil that held these plants. Adding these to your compost could spoil the entire batch. But for any plant that was healthy before it died, add the remains to your compost bag.
Remove Most Annuals
In general, these plants are easy to spot because after the first hard frost, many of them, including impatiens, begonias, and coleus, have withered and turned brown. If the spent foliage and blossoms on these plants are free of mold and disease, we put them in the compost pile.