Gardening Landscaping

How and When to Cut Back Ornamental Grasses

By
Marie Iannotti
Garden Writer Marie Iannotti
Marie Iannotti
Marie Iannotti is a life-long gardener and a veteran Master Gardener with nearly three decades of experience. She's also an author of three gardening books, a plant photographer, public speaker, and a former Cornell Cooperative Extension Horticulture Educator. Marie's garden writing has been featured in newspapers and magazines nationwide and she has been interviewed for Martha Stewart Radio, National Public Radio, and numerous articles.
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Updated on 11/19/24
Reviewed by
Julie Thompson-Adolf
Julie Thompson-Adolf
Reviewed by Julie Thompson-Adolf

Julie Thompson-Adolf is a Master Gardener and author with over 30 years of experience in year-round organic gardening; seed starting, growing heirlooms, and sustainable farming.

Learn more about The Spruce's Review Board
In This Article
Project Overview
  • Working Time: 20 - 30 mins
  • Total Time: 20 - 30 mins
  • Skill Level: Beginner
  • Estimated Cost: $0

The garden plants known collectively as ornamental grasses include dozens of species valuable in the garden as landscape plants. While some are true grasses (Poaceae family), there are also sedges, rushes, and other plants commonly included in this category. Most ornamental grasses are perennial plants with grasslike appearance and growth habits, loved for their foliage rather than their blossoms. However, once the foliage turns brown, you must trim ornamental grasses.

These plants add unique texture, form, motion, and even sound to the garden as they rustle in the breeze. And because many ornamental grasses are native species, they're favored among gardeners interested in natural and drought-tolerant landscaping. Cutting back dead ornamental grass can be a messy job, but there are some best practices to make the work easier and tidier.

Ornamental grasses cut back in front yard

The Spruce / Jayme Burrows

When to Cut Back Ornamental Grasses

Most ornamental grass should be cut in the spring or during the fall. However, the answer to the question of when to cut back ornamental grasses depends on the type grown. There are three main types of ornamental grasses: warm-season, cool-season, and evergreen.

Warm-Season Grasses

Warm-season grasses should be cut during the mid to late spring or fall, depending on the look you want to achieve. If you prefer a tidy garden, or if your ornamental grass is a variety that doesn't look great dormant, cut back these grasses in the fall. However, if you want to keep some interest in your garden throughout the winter, cut back these grasses in mid to late spring.

Warm-season grasses begin growing in mid to late spring, or even early summer. They thrive when the temperatures rise, with major growth and flowering occurring during summer's heat. Warm-season grasses turn brown in winter.

When you prune these warm-season grasses, cut them severely, right down to the ground. Some common warm-season grasses include northern sea oats (Chasmanthium), Japanese silver grass (Miscanthus sp.), hardy pampas grass (Erianthus), perennial fountain grass (Pennisetum), switchgrass (Panicum), and prairie cordgrass (Spartina).

Cool-Season Grasses

Cool-season grasses should be cut back in very early spring. Cool-season grasses grow primarily in spring before the temperatures exceed 75°F, and in fall when temperatures cool. These grasses keep their color throughout the heat of summer without much growth.

As soon as the snow clears, cut the grass back by two-thirds, leaving one-third in place. Pruning too drastically can harm the plant. Some examples of cool-season grasses include fescues, blue oat grass (Helictotrichon), tufted air grass (Deschampsia), and autumn moor grass (Sesleria).

Tip

Most ornamental grasses are perennial plants, coming back year after year. However, a few are grown as annuals that last for just one growing season, especially in cold northern climates. For these, it is best to dig out the roots of the plants to prepare the planting site for something new.

Evergreen Grasses

Evergreen grasses usually don't need to be cut back because they remain attractive through the better part of the winter. That said, if you need to trim them back, do so in late February or early March. Evergreen grasses grow year-round and keep their beauty throughout every season.

Warning

If you live in a region where wildfires are endemic, use ornamental grasses with caution. Rather than allowing the dead grasses to remain for their ornamental appeal, remove the foliage promptly at the end of the growing season. When planting ornamental grasses, keep them far away from your home and other structures. In some regions, authorities now caution against planting ornamental grasses and other plants likely to burn easily.

What You'll Need

Equipment / Tools

  • Pruning shears or a power hedge trimmer
  • Lawn rake

Materials

  • Biodegradable tape or bungee cords

Instructions

How to Cut Back Ornamental Grasses

Materials and tools to cut back ornamental grasses

The Spruce / Jayme Burrows

  1. Tie Grass Into Bundles

    The fuller the ornamental grass is, the messier it can be when cutting it down. While wearing gloves to protect your hands, start by bundling the stalks with any wide tape with good adhesive. Biodegradable paper tape is recommended for an eco-friendly approach. As an alternative, many gardeners like to use reusable bungee cords stretched tightly around the grass.

    Depending on the height of the ornamental grass, you might need to wrap each bundle of grass in two or three spots along the length of the stems. Especially wide plants might need to have their stalks divided into two or more sections before bundling.

    Yellow-green ornamental grasses tied into bundle with green tape

    The Spruce / Jayme Burrows

  2. Cut the Grass

    Now that the ornamental grass is neatly bundled, use pruning shears to cut the grass, either by two-thirds for cool-season grass or to ground level for warm-season grass. With the tape or bungee cords holding the grass blades in place, lean the bundle away from its base as you cut.

    If your ornamental grass is thick, a power hedge trimmer might be helpful. Either way, aim to keep the bundle intact as you cut. 

    Yellow-green ornamental grass cut below green tape tie

    The Spruce / Jayme Burrows

  3. Finish the Job

    Cutting each grass bundle is the bulk of the job. But there will undoubtedly be a few renegade blades outside of the bundle to clean up with pruning shears. Finish by raking the garden area to catch any loose blades of grass.

    Grass bundled with biodegradable tape or string can be easily tossed whole into a compost heap or municipal lawn waste site. If you have used vinyl tape, make sure to remove the tape as you dispose of the grass bundles.

    Tip

    If you are composting the dead grass stalks, speed up decomposition by cutting them into pieces before adding them to the compost pile. It's easy to do this when the grass stalks are still in bundles. When composting large amounts of dead grass, balance the mixture by adding wet, green material, or a few handfuls of nitrogen fertilizer to help break down. 

    Cut yellow-green ornamental grasses in middle of dead leaves

    The Spruce / Jayme Burrows

FAQ
  • What is the easiest way to cut back ornamental grasses?

    The easiest way to cut back ornamental grasses is to bundle them with wide and sticky tape and then cut them back with pruning shears.

  • What happens if you don't cut back ornamental grasses?

    If you don’t cut back your ornamental grasses, they might look untidy with depreciated foliage and spread their seeds in unwanted areas. Plus, fresh foliage in the spring can have difficulty growing through the depreciated foliage.

  • How long do ornamental grasses live?

    Ornamental grasses live anywhere from three to 10 years but longevity depends more on the species and care.

The Spruce uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

  1. Grass Faux Pas. University of Illinois Extension.