Warm-season ornamental grasses should cut back / trimmed back in the fall so that they’re just 1 or 2 inches tall. Typically, they turn a brown shade when the weather gets colder. Once these grasses turn brown, it’s time to trim the grass back. If you prefer to tidy the garden in the fall or live somewhere where fire can be a hazard, consider trimming warm-season grasses. Those who live in areas where a fire isn’t a problem can leave those seed heads and dried ornamental grass in the garden for some winter interest. When ice or snow encrusts these ornamental grasses, it can be breathtakingly beautiful.
If you leave your trimming of the ornamental grass until spring, make sure that you use pruning shears to cut the grass to the ground, leaving a few inches. Do this by late spring before any new growth happens. A small percentage of these grasses don’t look good in cold weather, so cut those in the fall with sharp blades.
When to cut back ornamental grasses in the fall
Cool-season ornamental grasses, on the other hand, look great when the weather cools. You can keep the foliage in place until late spring. Cut them back once the snow is gone because most of the grass is now dead. Smaller cool-season grasses can be trimmed with pruning shears. Trim roughly 2/3 of the plant. Sometimes, it’s easier to tie a bundle around the grass so that it’s a clump. Cleanup is much easier that way.
If there is a large clump of grass, a weed eater might be necessary or some electric hedge trimmers. It’s best to do this each year in early spring. You can then put the bundle into the compost pile.
Divide your grasses because it’s a great way to boost the number of plants you get without spending more money. They remain active and are growing within the landscape.
When you have evergreen grasses, divide them only in the earlier springtime weather. This is the best time to do so because dividing plants can wound them, and they might not live in winter.
Can you trim ornamental grasses in summer?
Early summer is the right moment for warm-season grasses to start growing. The leaves tend to bloom then, too. You may need to wait until the ground is bare and the plants go dormant before you divide evergreen grasses. One way to do this is to dig up the clumps and pull them into multiple pieces, each with roots. Use sharp blades or your hands to get the best results.
Cutting back the grasses is essential for both warm and cool-season grasses. Many gardeners find that it doesn’t take much effort and helps the plant flourish.