Fall Garden Clean Up
By Kathleen Cue, Nebraska Extension Horticulture Educator
When cleaning up the fall garden, it’s hard to know what should be cleared away and what should stay. Gurus of tidiness opt for removing everything now in order to start with a clean slate in the spring. But is there such a thing as too much tidiness? It turns out that, yes indeed, that can be true.
Plant stems act as a catch-all, collecting leaves, twigs and other bits of organic debris around the crown of perennial plants. This mulch layer protects the crown and root system from weather extremes, making them more winter-hardy.
Did you know that 30% of all native bees nest in the hollow stems of plants? Another good reason for leaving the stems of annuals and perennials in place over the winter months! Removal of these materials can be done in April, after the native bees have left the stems where they’ve over-wintered.
Speaking of hollow stems, cutting back some perennials in the fall can allow water to make its way down into the crown of the plants, resulting in freeze/thaw damage and rot. Marginally hardy plants like caryopteris, butterflybush and chrysanthemum are some of the plants that can be adversely affected when cut back too soon. These plants should be left alone in the fall. Instead, cut back stems when new growth comes on in spring.
Without fail, vegetable garden plants should be pulled in the fall and removed from the site. This is a good sanitation practice that also removes harborage of over-wintering problem insects and diseases. The same is true for asparagus plants. Cutting back the stems in the fall means less problems with the asparagus beetle next year. If powdery mildew and black splotches on the leaves of your peonies was a thing this past growing season, all the more reason to cut back the stems now.
Frosts and snowflakes make the most of our landscape plants during the winter months. Nothing is prettier than ornamental grasses with frost laced through leaves and seeds. It lends a gracefulness and beauty to the landscape that would be missed if plants were removed in the fall.