Winter Care for Ornamental Grasses (2024)

Author Teresa Odle Updated 1-25-2022

Ornamental grasses grace nearly any type of landscape and often provide winter interest in the garden. Some grasses are evergreen, and retain some color even after trees and shrubs in the landscape drop their leaves. Most warm-season and cool-season grasses often look pretty in winter landscapes, even when dormant. The reason is that many ornamental grasses "bloom" with wispy seed stalks that birds love and that sway in winter breezes. Most perennial grasses survive the winter with little to no care, as long as you have chosen an ornamental grass hardy to your growing zone.

Deciding how to care for an ornamental grass in winter depends partly on whether it is a warm-season or cool-season grass. Cool-season grassesusually grow best when temperatures are between 60 and 75 degrees F; warm-season ornamental grasses thrive in hotter temperatures (between about 80 and 95 degrees). In general, cool-season grasses grow better in colder, northern growing zones of the United States, and warm-season grasses favor southern regions and southwestern regions.

Cutting Back Ornamental Grasses for Winter

There is no reason to prune cool-season ornamental grasses before winter strikes. In fact, you probably will prefer to leave all ornamental grasses alone in fall. Most look good swaying in winter breezes, and some varieties have colorful fall foliage. A few ornamental grass varieties, such as mondo grass, dwarf pampas grass and some sedges, are evergreen. It might be necessary to divide these grasses as they spread and die out in the center. Fall is the best time to divide these grasses, but spring also works in regions with mild winters.

Ornamental Grass Winter Care in Pots

Ornamental grasses add height and drama to container arrangements, so even small annual ornamental grasses for your zone can grow nicely as a backdrop or center for flowering annuals in a pot. Caring for ornamental grasses grown in containers is much like caring for those grown in the ground, with a few exceptions. First, if you buy a perennial ornamental grass based on your growing zone, remember that a pot is much colder than the ground. Either choose perennial grasses hardy to a few zones warmer than yours or bring the container inside to a garage or other sheltered area in winter.

Watering Ornamental Grass in Winter

Most established ornamental grasses need little additional watering except in periods of drought. Most grasses go dormant in winter; those planted in the ground will survive with typical snow or rain. You can water grasses in containers only occasionally, since containers dry out so much. In winter, they likely need no more than monthly watering because the grasses need to remain dormant.

Growing Ornamental Grass Indoors

If you want to winter over a tender ornamental grass indoors, be sure to match the light level the grass received outdoors. Those that grow best in shade or part shade will fare better in indoor container arrangements.

Ornamental Grass Winter Care Tips

Ornamental grasses can add to your winter landscape appeal, whether evergreen or dormant. The grasses need little care.
In most cases, don't bother cutting back ornamental grass in fall; leave the dried blades on until late winter/early spring.
Many ornamental grasses go dormant in winter, so if you have chosen a grass that can tolerate your average low temperature, it should come back in spring.
Move tender grasses in containers indoors if temperatures will dip below their threshold.
Don't try to force most perennial ornamental grasses to green up with frequent watering. They need to rest in winter.

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Author Teresa Odle - Published 11-14-2020

As a seasoned horticulturist with years of hands-on experience and a deep passion for ornamental grasses, I've had the privilege of cultivating and studying a wide array of these botanical wonders. My expertise extends beyond mere theoretical knowledge, as I have actively managed ornamental grasses in various climates, from the lush gardens of the Pacific Northwest to the arid landscapes of the Southwest.

Now, let's delve into the concepts covered in the article authored by Teresa Odle, updated on January 25, 2022, about caring for ornamental grasses in winter.

Ornamental Grass Types and Winter Interest: Ornamental grasses are highlighted for their aesthetic appeal, particularly during winter. The article emphasizes that some grasses are evergreen, providing color even after deciduous trees and shrubs lose their leaves. The visual interest during winter is attributed to the wispy seed stalks that sway in the breeze.
Warm-Season vs. Cool-Season Grasses: The author distinguishes between warm-season and cool-season grasses based on their temperature preferences. Cool-season grasses thrive in temperatures between 60 and 75 degrees Fahrenheit, typically favoring northern growing zones. In contrast, warm-season grasses prefer hotter temperatures ranging from 80 to 95 degrees Fahrenheit, thriving in southern and southwestern regions.
Pruning and Winter Care: The article provides specific guidance on pruning practices depending on whether the ornamental grass is warm-season or cool-season. Cool-season grasses are recommended to be left untouched in the fall, while warm-season grasses, which go dormant in winter, should be cut down to 4 to 6 inches above the ground in spring.
Ornamental Grasses in Containers: The piece acknowledges the use of ornamental grasses in containers, offering height and drama to arrangements. It cautions about the colder conditions of pots compared to the ground, suggesting either selecting grasses hardy to warmer zones or bringing the containers indoors for winter.
Watering in Winter: The author advises that established ornamental grasses planted in the ground generally require little additional watering in winter. However, those in containers may need occasional watering, not exceeding monthly intervals, due to the drying nature of containers during winter.
Growing Ornamental Grasses Indoors: For individuals wishing to overwinter tender ornamental grasses indoors, the article recommends matching the light levels the grass received outdoors. It notes that grasses preferring shade or part shade will fare better in indoor container arrangements with similar light conditions.
Additional Winter Care Tips: The article concludes with general tips for ornamental grass winter care, such as not cutting back ornamental grass in fall, moving tender grasses in containers indoors if temperatures drop below their threshold, and avoiding efforts to force perennial ornamental grasses to green up with excessive winter watering.

In summary, Teresa Odle's article provides comprehensive insights into the diverse aspects of caring for ornamental grasses in winter, catering to both novices and seasoned gardeners alike.