How, When, and Why to Cut Back Ornamental Grasses

Ornamental grasses are increasingly being used in our landscapes as an alternative to shrubs. In any region of the country, you can find native grasses that do quite well, and add textural variety and a soft, flowing aspect to the garden.

How, When, and Why to Cut Back Ornamental Grasses | GardenersPath.com

These plants are particularly attractive when planted in groups. Examples include any of the many miscanthus varieties, blue fescue (Festuca glauca), and Mexican feather grass (Nassella tenuissima).

A few are evergreen in the southernmost parts of the United States. But most are deciduous, rewarding gardeners year after year with fresh blades in solid or variegated green, red, and coppery colors, as well as prolific and attractive plumes and seedheads.

And while largely maintenance-free, many of these plants do benefit from an annual haircut. Let’s learn more about how to trim them up for maximum growth and beauty.

Enjoy Them Throughout Winter

While you likely won’t do any irreparable harm if you trim ornamentals back in the fall, we recommend you wait until late winter or early spring before you bring out the shears.

Many of these plants — especially those with spent plumes and attractive seed heads — offer alluring winter interest, particularly if snow or ice graces their foliage.

Pruning Ornmental Grasses | GardenersPath.com

Keeping the leaves around also protects the crown of the plant throughout the winter, but you do want to prune the old growth before the new growth begins. Leaving the dead material on too long can impair the crown’s warming and delay new growth by as long as three weeks.

If you delay the haircut until after new shoots have appeared, you’ll want to trim the old material carefully. If you cut the new blades, they’ll have a raggedy, unnatural appearance all season.

Here in Austin, we prune our big grasses back in late January. Floridians can start chopping in early January, while our northern friends may have to wait until later in spring.

How Low Should You Go?

Start with a very sharp pair of hedge clippers, such as these from Fiskars, available via Amazon.

The 10-inch blades on these clippers will help you to get through any clump of grass quickly. Be sure to sharpen your blades frequently, as the grass will dull them.

Some gardeners use a hedge trimmer or even a chainsaw on older and tougher grass clumps.

Next, put on a long-sleeved shirt; the blades can be quite sharp!

Fiskars 9191 Power Lever 8-Inch Hedge Shears With Soft Grip Handle

Tightly tie twine, rope, or a bungee cord around the clump, about two feet up from ground level, and cut below the tie. This makes it easier to access the clump as you cut it, and it also provides you with a neat, tidy bundle to carry away and dispose of.

How short you cut these plants depends on whether they are cool-season or warm-season grasses. While the cool-season varieties grow best when temperatures are 60 to 70°F, the warm-season grasses like it hot, and prefer temperatures in the 80 to 95°F range.

Warm-season grasses that are taller than 3 feet should be cut back to 4 to 6 inches from ground level. Shorter mature plants can be cut back to about 3 inches.

Prune cool-season grasses back by two-thirds.

The Greens Get a Rake

Some ornamentals, such as Fakahatchee grass (Tripsacum dactyloides), are evergreen in some parts of the country. For these types, just rake through them a couple times a season with gloved hands to draw out any dead material.

How to Prune Ornamental Grasses in the Garden | GardenersPath.com

If an evergreen grass grows to be too large, you can cut it back every couple of years. And of course, clip out the occasional dead blade as you encounter it.

Low Maintenance and Attractive

Elegant and flowy, ornamental grasses make a visually appealing addition to modern landscapes.

Cut them back as winter wanes and you’ll be rewarded with fresh and bright blades in springtime, and attractive plumes of seedheads in late summer and fall.

How and When to Cut Back Ornamental Grasses | GardenersPath.com

Do you have any of these types of plants in your landscape? When do you cut them back? Tell us about it in the comments section below, and learn more about ornamental grasses here.


Don’t forget to Pin It!

A collage of photos showing different types and varieties of ornamental grasses.

Product photo via Fiskars. Uncredited photos: Shutterstock.

About Gretchen Heber

A former garden editor for a daily newspaper in Austin, Texas, Gretchen Heber goes through entirely too many pruners and garden gloves in a year’s time. She’s never met a succulent she didn’t like and gets really irritated every 3-4 years when Austin actually has a freeze cold enough to kill them. To Gretchen, nothing is more rewarding than a quick dash to the garden to pluck herbs to season the evening meal. And it’s definitely time for a happy dance when she’s able to beat the squirrels to the peaches, figs, or loquats.

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Kristi Brooks
Kristi Brooks (@guest_3113)
1 year ago

Hallelujah ! Great advice. Here in SoCal we see huge clumps of ornamental grasses cut back in fall and looking like giant mounds. They never seem to recover. Well done!

Sandy
Sandy (@guest_5001)
1 year ago

Hi, I have 4 Black Stockings Dark Fountain Grass plants. I’m in Florida and planted them in May. They are doing so well and got so tall that some of the stalks are falling over. Can I trim them back now since have gotten so tall?

Jerry
Jerry (@guest_5176)
11 months ago

Hi,
I am wanting to plant some tall grasses (3 to 4ft) along the edges of my driveway. I don’t have room for ones that get large in diameter. Are there some that stay about 8″ in diameter? Or can you tell me how to keep them in small clusters? We have some in other areas of our yard but they have grown to be about 18″ in diameter, to big to put in the area. What can you advise me? We live in the northern part of Utah with hot summers and cold winters.

Courtney S
Courtney S (@guest_5407)
10 months ago

I live in Connecticut and am in a new house. Our ornamental grasses are starting to drape over the driveway which will be dangerous and annoying come
Snowfall. However it’s now below freezing most nights here. Can I still trim these grasses (maybe just the part that encroaches the driveway?) without damaging them?
Thanks,
Green Thumb Wannabe

Kimberly Childers
Kimberly Childers (@guest_5975)
6 months ago

Love your simple info about grasses! I write a column, Consider the Garden, for a paper here in Santa Rosa California. It’s just about time to cut the grass is back my front yard is kind of wild with grasses and my backyard is more formal English. People that don’t Garden don’t understand what gardening is to us, right!? To watch a fern frond unfurl is pure Magic and now it’s going to be raining for days which is wonderful and much-needed. Thanks

Allison Sidhu
Allison Sidhu (@allison-sidhu)
Admin
Noble Member
Reply to  Kimberly Childers
6 months ago

Thanks for getting in touch, Kimberly! I was able to check out some of the back issues of the Upbeat Times online and I loved your January 2019 column, “The Quiet Garden.” Enjoying the much-needed rain immensely here in Los Angeles as well. 🙂

Perhaps you’d like to check out my piece on enjoying World Naked Gardening Day with all of the five senses, if you haven’t read it already.

Natalia M
Natalia M (@guest_6932)
4 months ago

Hi! Thanks for the info! I live in sunny Los Angeles and wanted to plant Miscanthus Morning Light in my front yard (Front and Center). Do I need to trim it back 4-6” in the winter/spring even being in So Cal? I worry that if this is the case, I may not be able to have them front and center as I had planned since they will look so bad after being trimmed back. Thanks for any help or guidance you can offer!

Matt Suwak
Matt Suwak (@mattsuwak)
Member
Trusted Member
Reply to  Natalia M
4 months ago

Hey Natalia! If you want the Miscanthus to bloom you should cut it back in the winter. Miscanthus is considered a cool season grass, and it puts on most of its growth in the early spring so that it’s at its best by late spring or early summer. If the grass isn’t trimmed it will grow wild and lopsided, and if it blooms the display will be lackluster. I’m not a big fan of cut back perennial grasses either, but if you hack it back to a height of 5-7 inches, you could then carefully trim the ragged ends so… Read more »