FALL CLEAN-UP IS IMPORTANT
TO PERENNIAL GARDENS

Cleaning out the vegetable or annual flower garden after a hard freeze is nothing unusual for most gardeners. However, many gardeners are less likely to do a thorough clean-up to the perennial flower garden. Perhaps this is because many perennials continue to grow and even flower late into the fall, so clean-up is often delayed. Weather then becomes cold and the days are short. Outdoor activities in the garden then become unpleasant and may seem unnecessary until spring.

While the weather is still warm enough for outdoor gardening, check over the condition of the perennials. Look especially for plants that may have diseased leaves. Diseased dead leaves may serve as a source of infection for next spring. Dead leaves should always be removed for an attractive appearance. Pests, such as spider mites, may also survive winters on old foliage or deep in the crowns of plants that maintain some green foliage most of the winter. If such pests were a problem this past summer, consider using a late season pesticide spray to control as many of these pests as possible.

Many perennials maintain foliage throughout the winter. A few of these include foxglove, chrysanthemum Oriental poppy, bergenia, hellebores, and violas. A mulch placed around them soon can be helpful for protection against rapid temperature changes of soil and air around them. The best winter protection for most perennials is usually a mulch base and sufficient moisture in the soil.

The old adage “an ounce of prevention is worth a pound of cure” holds true for fall cleanup. October is a good month to prepare perennial flowers for winter to insure a good floral display next year. Here are a few considerations for some of the most popular perennial flowers.

Peonies need little care, but in October the tops should be cut off. If the leaves were infected with any of the leaf blights that cause dead spots, the tops should be eliminated from the garden. Peonies may still be dug, divided and transplanted in October. Healthy peonies can flower well for many years without division.

Phlox are plants subject to disease and mites causing the most severe damage on lower leaves. Powdery mildew can also be a problem. Prompt removal of foliage by cutting plants back to near ground level at this time is important. Crushed, dead, infected leaves that fall to the ground while cutting off the tops should also be gathered and removed from the flower bed.

Daylilies have few pest problems, but sometimes mites or thrips may cause damage. Remove spent flowers and damaged foliage to reduce hiding places. Winter sensitive daylilies are best protected with full foliage and some mulch protection.

Hardy hibiscus, or rose mallow, has completed growth at this time. New shoots develop from the base of the plant in late spring. At this time, tops may be cut off an inch or two above the soil. Large clumps are normally divided in early spring.

Chrysanthemums are considered a perennial plant but many don’t survive because they were planted too late in the season and the foliage/stems are cut back in early winter. This allows the cold to translocate into the root system of the plant. Do not cut back the mum the first year to reduce this shock but mulch the root ball after the greenery has browned. In subsequent years, the dead foliage may be removed because the plant has an established root system.

Caring for your perennials in late fall will assure the vitality of the plant for spring renewal.