Ornamental grasses are an attractive and interesting detail in our fast-fading fall gardens. With many delicate flowering plants going to sleep for the winter, ornamental grasses can provide texture and interest in an otherwise drab garden or flowerbed. There are a few things to know about these lovely plants as we enter the colder months here in Minnesota.
Your ornamental grasses will need to be divided every 3 to 5 years. Their new growth occurs on the outer rim of the grass clump, and as this happens, the center of the clump loses viability and eventually begins to die. Although many perennial plants thrive with fall division, ornamental grasses do not. They require more time to reestablish in the soil than many other perennials; thus, dividing them this time of year can be detrimental to their survival. Dividing your grasses in the spring will yield much healthier and happier plants!
Cutting back your ornamental grasses in late fall versus the early spring is a decision that is entirely yours. Some don’t appreciate the mess the large scattered plumes leave behind in flower beds and yards, but others enjoy the wildlife they can attract during the bleak winter months. Birds particularly like to feed on the seeds of many varieties of grasses. The root systems of these hardy grasses do not need any insulation to survive the winter, so leaving them to sway in the winter winds until the snow flies is a completely reasonable option.
If you do decide to cut back your grasses in the fall, using a two-step approach can get you more benefit for your labor. The top tufts should be cut first and discarded in your yard waste bin. The bottom of the stalks, which you can cut down to 3 or 4 inches above the soil, make great compost. Use a pair of electric hedge trimmers as opposed to hand shears for an easier time of things.
Ornamental grasses are usually one of the last decorative plants left standing by the time late fall rolls around. The choice to cut or leave them is up to you. You may be hoping for one last hurrah in your garden, and this would give you that opportunity. But you may be eager to see what kinds of winter foragers will come to nibble on them if you leave them be.