How to Cut Back Ornamental Grasses, According to Pro Landscapers

There are many different types of ornamental grasses, with a selection for virtually any climate or condition. These plants are relatively resilient and require little maintenance. However, pruning them is important, as it helps maintain their shape, size, and form—by removing dead foliage, you're also preventing mildew, mold, and pests.

Pruning your ornamental grass is important from an aesthetic perspective, too. Cutting back will improve a plant's overall appearance, adding to an attractive landscape and ensuring beautiful, fresh new growth. Here, experts gave us their tips and tricks for properly pruning these grasses—from their favorite varieties to common mistakes you should avoid.

Types of Ornamental Grasses

Grasses grow in almost every environment around the world, says Camille Cimino, landscape designer at The Nature of Things. “Regardless of where you live, you can find an abundance of options that work in your area," she says.

Denis McCausland, a professional landscaper with over 30 years of experience, like feather reed grass. It's hardy and can handle the heat and extreme cold—making it a good fit for most places in the United States. “It grows vertically, up to about five feet tall, and is characterized by its beautiful, feathery plumes,” he says. “Other than moderate watering requirements, it’s also extremely low maintenance, which makes it an attractive choice for busy homeowners.”

Other popular ornamentals include Carex, Miscanthus, Muhlenbergia, Pennisetum, and Stipa, according to Cimino.

Angelika Zaber, a lawn care specialist at Online Turf, says ornamental grasses offer a unique combination of form, texture, and movement, with many varieties featuring attractive flowers that last for months during the summer. “These grasses also come in many sizes and forms, from compact varieties suited for containers to taller grasses that are perfect for vertical elements,” she says.

When to Prune 

The ideal time to prune ornamental grasses depends on the type, though most will benefit from pruning in either the fall or spring. “The timing varies based on whether the grass is a warm-season, cool-season, or evergreen variety,” says Zaber. “For example, warm-season grass should be pruned in early spring, before new growth begins, or during the fall. Cool-season grasses should be cut only in early spring.” 

Evergreen grasses should be pruned to shape and have dead growth removed throughout the year, says Cimino. “Deciduous bunch or spreading grasses can be cut down to the ground or shaped for new growth,” she adds.

How to Prune 

Before you begin, you may need to collect a few things. “The main tool required is a pair of sharp pruning shears,” says Zaber. “If the grass is particularly thick or dense, a power hedge trimmer may be helpful. Both tools allow for precise cutting, ensuring the grass is properly maintained.”

Bundle the Grass

A fuller ornamental grass can be difficult to cut down, so the first step is to tie the grass into bundles. You want to prevent it from moving while you’re pruning. “Make sure to wear gardening gloves and use wide tape, preferably biodegradable paper tape if possible,” says Zaber. “If the grass is tall, secure the bundle in two or three spots along the stalks.” 

Cut to the Correct Height

Once it’s bundled, trim the grass to the correct height. “For cool-season grasses, cut about two-thirds of the way down—warm-season grasses should be cut to ground level,” says Zaber. “As you cut, hold the bundle steady with the tape, tilting it slightly away from the base. If the grass is dense, use a power hedge trimmer. There may be a few stray blades, which you can trim with shears.”

Remove the Dead Grass, and Pamper the Rest

Once you remove the cut grass, you may want to fertilize, depending on the time of year. “Pruning can add stress to the plant, so watering is generally recommended afterward,” says McCausland. 

Common Mistakes

Most mistakes can be avoided by knowing what type of ornamental grass you have and understanding the specific needs of each variety. “Pruning too heavily or too often can damage the grass and reduce its overall health; using the wrong tools can result in uneven cuts or unnecessary damage,” says Zaber.  “Additionally, pruning at the wrong time—either too early or too late in the season—can disrupt the grass’s natural growth cycle and cause it to struggle.” 

Pruning with dull or rusty pruning shears can also result in uneven cuts, which can be an attack vector for disease and pests, warns McCausland. “Don't butcher your ornamental grass,” he says. “Make sure to maintain the recommended minimum grass height, or else you may permanently damage the crown.”

The good news, according to Cimino, is that grasses are resilient. “It's most important to prune dead material out as needed,” she says. “You can prune ornamental grasses to shape anytime, cut them completely back to the woody parts, or whack them to the ground during dormancy.”