How to Cut Back Ornamental Grass

Ornamental grasses need to be cut to be able to display their full beauty. Are you doing it correctly?

Ornamental grasses are a joy to have on your property. Choose one that is native to your area, and it will require low maintenance and be simple to care for. I love it when I see any ornamental grass swaying in the breeze!

However, as with all seasonal plants, there will come a time when you need to begin pruning them. Today, we will go over everything I know about the subject!

When to Cut

One of the many advantages of ornamental grasses is that they are incredibly resilient and tolerant.

Almost all ornamental grasses can be trimmed back at any time, from early fall to late spring.

During the growing season, they can be cut to form. Shear off a small amount of top growth as needed.

Although many people prefer to cut back their grasses in the fall, ornamental grasses are a great plant to leave up through the winter.

Once the snow has melted, cool-season grasses should be pruned. These plants emerge from the earth in the spring. If you don’t trim them in a timely manner, you’ll end up with lush plants with chopped-off leaf tips because you didn’t do it early enough!

Pruning old and grown grass

How Far to Prune Back?

Cool-season grasses should not be trimmed too short because this can cause irreversible damage. Leave about a third of the previous year’s growth in place. It will be quickly hidden by the new vegetation.

Warm-season grasses can be trimmed all the way to the ground at any time. If you wait too long, leave 6 to 8 inches of old-growth to protect the new leaves and avoid cutting off the new leaf tips.

The Conventional Method

You have a few options for trimming your decorative grasses.

You can use hand pruners, sickles, hedge trimmers, or a weed eater-type equipment with a blade instead of the nylon line. The tool you use will be determined by how much you need to cut back and what you have on hand.

Trimming With a Bread Knife

Surprisingly, the serrations on a bread knife make it ideal for cutting ornamental grasses. 

Grab your cheapest bread knife or look for an old bread knife at a thrift store. Because it can be challenging to use a bread knife while wearing thick gloves, consider pruning when it’s warm enough for you to do it with bare hands.

freshly trimmed old river grass

Burning It Back

Ornamental grasses can also be burned back. This should only be done with warm-season grasses. Cool-season grasses’ dead leaves should not be burned. The developing tips may be harmed if you burn them.

I would not recommend this method for removing old growth. It could lead to fire-related mishaps. Many communities prohibit this method outright.

If you’re going to use this method, exercise extreme caution. The best time to do it is in winter when there is little chance that a fire will spread.

Tips for Pruning

Some grasses have jagged edges. Gloves are strongly recommended when handling these plants. When working with grasses such as Miscanthus, you should wear gloves and long sleeves. 

Consider using a large bungee cord to tie up your grass if you want to avoid a mess on your lawn. Stretch it around the grass about 2 feet from the base and then cut the grass. It makes cleaning up a lot easier.

white gloves and plant cutters and scissors on the grass

Dividing Clumps

Mature plants may require a little extra care to keep them looking their best. By dividing large clusters of plants, they can be kept healthy for years.

Before dividing ornamental grasses, wait until the ground has thawed. Then, start by digging up the entire ball of grass.

Remove the “dead” center section and place it in the compost bin. Only use pieces of the newer growth on the outside of the root ball for replanting.

Slice the remaining root ball into several pieces and replant them. If the slice is larger, the first-year plant will also be larger.

No matter the size, the replanted piece will sprout new growth as the weather warms.

Evergreen Cool Season Grasses

These grasses are evergreen and do not need to be cut back. 


Helictotrichon is a cool-season evergreen clump-forming grass that grows to 2 feet tall by up to 3 feet wide with blue-gray leaves radiating out like a bristly porcupine. The light tan flowers are on erect spikes that rise a foot above the foliage in mid-summer. In temperate regions, this plant is evergreen, but in locations with harsher winters, it is considered semi-evergreen.


Luzula is a grass-like plant that thrives in wet, shaded environments. This plant produces hairy, grey-green leaves in late spring with stalks of pristine white blooms that transform into brown seed heads. The flowers are wonderful for cutting, either fresh or dried. This plant makes a beautiful border plant and is also great for bulk planting in the shade.

Luzula flowering grass snowhite


Sesleria autumnalis is a clumping cool-season grass that blooms slowly at the start of the season. However, it begins to put up an incredible display in the middle of the summer. Silvery-white inflorescences appear on thin stalks and float above the leaves. When mass-planted, the effect is lush and lovely.


Carex, often known as Sedge, is not technically a grass, although it has the appearance of one. Sedge grass is a shade-loving, usually evergreen plant that mixes in with most other plants in terms of texture. Many carex are also well-suited to more ordinary landscapes, such as lining paths in a forest garden. This plant thrives in a damp environment and is an excellent companion plant for hostas.

Jeffrey Douglas
Jeffrey Douglas own a landscaping company and has been in the business for over 20 years. He loves all things related to lawns or gardens and believes that proper maintenance is the key to preventing problems in the first place.
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