August 28, 2015
Fall Perennial and Ornamental Grass Maintenance
Fall is the season when I enjoy hayrides, bonfires, high school football games and apple picking. In my garden, the late blooming perennials provide me with bursts of color in shades of yellow, purple and pink. Some of the perennials that I cut back earlier in the season have come back into bloom, such as the Purple Salvia and Blue Catmint. Ornamental grasses, which have provided interest all season, are now turning color and producing beautiful flower heads. The garden is still vibrant, yet as a gardener, I begin to think about preparing my plants for the harsh winter to come.
In late summer, I go through the garden to decide what I will be cutting back and which plants I will keep to provide winter interest and food for the wildlife. The seeds provided by Echinacea (coneflower) and Rudbeckia (Black-Eyed Susan) are very desirable to birds and I always leave these standing. The large flower heads of upright Sedums are so beautiful dusted with snow and can be left. Fall blooming Chrysanthemums and the woody stems of purple Russian Sage are best pruned in the spring. Evergreen perennials, such as Coral Bells, European Ginger, Liriope and Evergreen Ferns, are important in my winter garden as they provide interest in an otherwise barren landscape. Their winter-damaged foliage will need to be pruned in the spring.
The many ornamental grasses in my yard are a winter favorite as the brown blades and flowers stand tall above even the deepest snow and provide movement and shadow in the winter landscape. Cut grasses back in March, before the new blades begin to grow, with a hedge or long-bladed pruner. Every few years in early spring it is time to tackle the daunting task of dividing the grass clumps. A strong back and sturdy shovel are needed to dig up the entire plant. I use a straight-edged shovel to break the clump into pieces, which are then replanted.
Any perennials with diseased foliage or pests, can be cut back and the foliage disposed of. Perennials such as Beebalm, Phlox and Peonies, which are prone to powdery mildew, usually fall into this category. The strappy leaves of the many Day Lilies, which dot my property, and the early blooming Bearded Irises I cut with scissors to prevent pests from damaging the bulbs. When cutting back perennials, leave a few inches of stem to protect the plant crown. After the first killing frosts, I continue to prune back any blackened damaged foliage.
As I wander the gardens in early fall, I look for any perennials which have not performed as well this year, or which are starting to die back in the middle of the clump, these are indicators that it is time to divide the plant. Division can be done in early spring or fall, when the plants are dormant. If doing this task in fall, allow plenty of time for the roots to establish so the plant will not be pushed out of the ground with the freeze/thaw cycles. I will dig up the entire plant, and then divide it into pieces with a portion of root (by hand, or with a sharp tool). The new sections are then replanted or perhaps swapped with other gardening friends for some of their excess perennials.
My fall garden chores also continue to include watering, especially if it is a dry season, until the ground is frozen. It is important that the plants are well hydrated to enable them to survive the harsh winter months. A few inches of mulch around the perennials in the garden can elevate the soil temperature 5 to 10 degrees and provide some warmth during the winter months.
Although I am busy with many fun fall activities, I always spend time in the garden to prepare my perennials for the winter ahead. Time spent in the fall will assure that your plants survive the winter and also make spring cleanup an easier task.
Kathy Evans | Greenhouse Design & Sales