Fall Pruning: A Guide to What Perennials to Cut Back and What to Leave
When autumn arrives and the first frost hits, many gardeners reach for their pruning shears. But before you start cutting back all your perennials, it’s important to know which ones should be pruned in fall and which ones should be left alone.
Why Leave Some Perennials Uncut in Fall?
Leaving some perennials uncut in fall can actually benefit your garden. Here are a few reasons why:
- Winter interest: Dried stalks, fading leaves, and seed pods can create a beautiful and unique winter landscape.
- Protection from the cold: Dead plant material can insulate the soil and protect plant roots from freezing temperatures.
- Food and shelter for wildlife: Birds, insects, and small mammals rely on uncut perennials for food and shelter during the winter months.
Perennials to Leave Uncut
Not all perennials should be left uncut in fall. Here are some types that benefit from being left alone:
- Perennials that feed birds: These perennials have seedheads that provide food for birds during the winter. Examples include ornamental grasses, purple coneflowers, and sunflowers.
- Perennials that are home to beneficial insects: Some native plants provide shelter for beneficial insects over the winter. Examples include hardy geraniums and dianthus.
- Low-growing perennials: These perennials, such as moss phlox and hellebores, don’t need fall pruning.
- Evergreen or semi-evergreen perennials: Perennials with evergreen foliage, such as hellebore and Christmas fern, can be left uncut until spring.
- Perennials that add winter interest: These perennials, such as switchgrass and feather reed grass, provide movement and visual appeal in the winter landscape.
Perennials to Cut Back in Fall
While some perennials should be left uncut, others should be pruned back in fall to promote healthy growth and prevent disease. Here are some types that should be cut back:
- Diseased perennials: Plants that are infected with disease should be pruned back to prevent the disease from spreading.
- Pest-infested perennials: Perennials that are infested with pests should be cut back to remove the pests and prevent them from overwintering.
- Perennials with new basal leaves: Some perennials, such as Shasta daisy and globe thistle, grow new leaves at the base of the plant in fall. These leaves should be left uncut to protect them from the cold.
- Tender perennials: Tender perennials, such as roses and butterfly bushes, are not as cold-hardy as other perennials. Pruning them back in fall helps to protect them from winter damage.
How to Prune Perennials in Fall
When pruning perennials in fall, follow these tips:
- Leave about two inches of stem above the soil to mark the plant’s location.
- Use bypass pruners or hedge clippers for clean cuts.
- Don’t compost any infected or diseased stems and leaves.
By following these guidelines, you can ensure that your perennials are properly pruned for the winter and will thrive come springtime.
