Calamagrostis, Feather Reed Grass 'Karl Foerster'

Calamagrostis acutiflora

Family: Poaceae (poh-AY-see-ee) (Info)
Genus: Calamagrostis (ka-la-mo-GROSS-tis) (Info)
Species: acutiflora (ak-yoo-tih-FLOR-uh) (Info)
Cultivar: Karl Foerster
View this plant in a garden


Ornamental Grasses and Bamboo

Water Requirements:

Average Water Needs; Water regularly; do not overwater

Sun Exposure:

Sun to Partial Shade


Grown for foliage


Foliage Color:

Unknown - Tell us


4-6 ft. (1.2-1.8 m)


24-36 in. (60-90 cm)


USDA Zone 5a: to -28.8 C (-20 F)

USDA Zone 5b: to -26.1 C (-15 F)

USDA Zone 6a: to -23.3 C (-10 F)

USDA Zone 6b: to -20.5 C (-5 F)

USDA Zone 7a: to -17.7 C (0 F)

USDA Zone 7b: to -14.9 C (5 F)

USDA Zone 8a: to -12.2 C (10 F)

USDA Zone 8b: to -9.4 C (15 F)

USDA Zone 9a: to -6.6 C (20 F)

USDA Zone 9b: to -3.8 C (25 F)

Where to Grow:

Unknown - Tell us


Parts of plant are poisonous if ingested

Bloom Color:


Bloom Characteristics:

Unknown - Tell us

Bloom Size:

Unknown - Tell us

Bloom Time:

Late Spring/Early Summer

Other details:

Unknown - Tell us

Soil pH requirements:

6.1 to 6.5 (mildly acidic)

6.6 to 7.5 (neutral)

7.6 to 7.8 (mildly alkaline)

Patent Information:


Propagation Methods:

By dividing the rootball

Seed Collecting:

N/A: plant does not set seed, flowers are sterile, or plants will not come true from seed


This plant is said to grow outdoors in the following regions:

Anchorage, Alaska

Denver, Colorado

Fort Collins, Colorado

Longmont, Colorado

Glastonbury, Connecticut

Ocean View, Delaware

Rehoboth Beach, Delaware

Boise, Idaho

Chicago, Illinois

Hinsdale, Illinois

Spring Grove, Illinois

Washington, Illinois

Greenville, Indiana

Petersburg, Indiana

Portland, Indiana

Shawnee Mission, Kansas

Bardstown, Kentucky

Baltimore, Maryland

Ijamsville, Maryland

West Friendship, Maryland

Boston, Massachusetts

Reading, Massachusetts

Roslindale, Massachusetts

Ferrysburg, Michigan

Garden City, Michigan

Holland, Michigan

Ludington, Michigan

Cottage Grove, Minnesota

Kasota, Minnesota

Little Falls, Minnesota

Minneapolis, Minnesota(2 reports)

Perham, Minnesota

Billings, Montana

Fort Benton, Montana

Polson, Montana

Lincoln, Nebraska

Pahrump, Nevada

Los Lunas, New Mexico

Lockport, New York

Elizabeth City, North Carolina

Raleigh, North Carolina

Summerfield, North Carolina

Grand Forks, North Dakota

Cleveland, Ohio

Mogadore, Ohio

Richfield, Ohio

Portland, Oregon

Dover, Pennsylvania

Downingtown, Pennsylvania

Monaca, Pennsylvania

Roscoe, Pennsylvania

Wilkes Barre, Pennsylvania

Millington, Tennessee

Austin, Texas

Round Rock, Texas

Sanger, Texas

Park City, Utah

Linden, Virginia

Mc Lean, Virginia

Clinton, Washington

Olympia, Washington

Seattle, Washington

Vancouver, Washington

Walla Walla, Washington

Eau Claire, Wisconsin

Green Bay, Wisconsin

Madison, Wisconsin

Menasha, Wisconsin

Pewaukee, Wisconsin

show all

Gardeners' Notes:


On May 8, 2015, saya from Heerlen,
Netherlands (Zone 8b) wrote:

I've removed C. Foerster because in my garden it did 'nt look so nice..a little messy in fact. The clump does collapse and it looks rather strange to tie these up. I have C.'Overdam' in my garden too which has a nice sturdy habit. C. Foerster reseeds, C. 'Overdam' does 'nt. Of course I kept 'Overdam'.


On Apr 17, 2015, dduff from Fort Collins, CO (Zone 5b) wrote:

Popular for a reason, this grass is attractive and fast growing. Like many grasses, it thrives in heat and full sun but is much less impressive in shade.

Pros: It's an early grower -- one of the first signs of Spring here. It has year-round interest with it's attractive shape and seed heads. I only cut it to the ground just before it starts growing again (mid-March). It's very drought tolerant and easy to propagate. No problems from rabbits.

Cons: Main negative is the lack of uniqueness. It's very widely used here.


On Jun 6, 2014, coriaceous from ROSLINDALE, MA wrote:

This is one of the most popular of ornamental grasses. It is valued for its vertical lines, its early bloom, and its tolerance of wet/clay soils. It's tough and highly adaptable, a clump former that isn't aggressive.

This is one of the earliest of grasses to emerge from dormancy, and one of the earliest grasses to bloom. The tightly vertical flower stalks rise to 6' in June, providing screening or vertical emphasis early in the season. I find they generally last till after Christmas, but snow can permanently topple them. Cut them back no later than early spring, to avoid cutting back the new growth.

It is winter hardy in Regina, Saskatchewan, Z3.

I find no authority stating that this is toxic when ingested.

This plant is sterile a... read more


On Jun 6, 2014, jscaldwell from Round Rock, TX wrote:

Two years in the ground and still anxiously waiting for mine to bloom. Hoping it isn't too hot here for 'em.


On Oct 5, 2013, Liz53 from Clinton, WA wrote:

I planted a dozen or so 1 gallon Karl Foersters this past spring as a temporary screen behind a permanent screen of loosely arranged wax myrtles as they established themselves. The KFs immediately sent up bloom stalks to 6' tall (perfectly fulfilling their purpose) and had a beautiful changing display throughout the spring and summer. Some have stayed relatively compact. Others, the ones planted within the reaches of my drip system have doubled, maybe tripled in circumference. They are starting to encroach on the wax myrtles, which also thrived this summer, and now (October) I will be relocating them to a new permanent location where they will again serve as a beautiful screen. I expect them, even with transplanting, to be even more satisfying next year.


On Mar 6, 2012, lindypuddin from stony mountain, MB (Zone 3a) wrote:

I grow this beautiful grass in my mixed beds with shrubs and perennials Manitoba Zone 3a. As my neighbor in Saskatchewan says, it is the perfect landscaping plant even in our areas. it has a height of 5-6 feet with seed; stays in a clump, not invasive. Vertical shape fitting in perfect in a mixed bed.

Needs to be in a moist yet well- drained area; fertilize well in early spring, it grows quickly. Its height and movement looks great through the snow. Now I'm also trying 'Overdam'.


On Feb 29, 2012, marywalters from Holland, MI wrote:

Because this ornamental grass grows narrow & upright, it softens (without completely concealing) the harsh lines of utility boxes that stick out like a sore thumb in your yard. Great for other low growing eyesores you wish to camouflage. I've seen it growing in my downtown area in very narrow spots around concrete as a hedge plant - so it takes heat & humidity very well. Gorgeous in groupings in a perennial garden. Pairs well with Sedum Autumn Joy and Perovskia.


On Feb 25, 2010, darylmitchell from Saskatoon, SK (Zone 3a) wrote:

I inherited four mature clumps of Karl Foerster when I moved into my house. They are outstanding accent plants that look great from mid-summer until spring when I cut them back. They're valuable in the winter landscape, especially in a cold northern climate with many months of snow.

Its height provides structure and architecture. The sight of the grass swaying in the breeze adds movement to the landscape. The seed heads are tall and wheat-like, changing from a pinkish colour to a vibrant gold in the fall. Paired with perennials like purple coneflower, sea holly or globe thistle, they make a striking combination. The colour is retained through the winter and makes them a standout in the relatively colourless winter months. In the spring, I cut down the grass to about si... read more


On Jun 21, 2009, petitesyrah from Boise, ID wrote:

I have two groups of three of these. They are about five years old and get bigger every year. I'm neutral to negative on them because they do not stand up to any rain or wind. Once flattened by a single downpour or gust, they never recover. I have to cut them down because they are a flattened mess. I tried using peony hoops when they emerged this spring, but they are just too big and heavy. And sometimes the centers rot, making them grow in donut shapes.


On May 29, 2009, shelly80504 from Longmont, CO (Zone 5a) wrote:

Looks good in all seasons. Adds vertical interest. Love to watch/hear the seed spike sway in the breeze. For a grass it tends to stay in its clump rather than spreading all over like some of them do.


On Apr 27, 2009, leelynne from Dover, PA (Zone 6a) wrote:

This ornamental grass is great. I have 2 of these and they grow like there is no tomorrow. They even take transplanting well. I didn't know if you were supposed to cut the old reeds off or not so this spring I cut them back. Hopefully they will get new reeds on them this year. The reeds are beautiful and very showy. I love to hear the reeds moving on breezy summer days.


On Jul 13, 2007, Meig from Timnath, CO (Zone 5b) wrote:

This grass is indestructible and will grow anywhere you plant it. It handles all soil types and the bitter winter winds on my property don't faze it.

May 2015: still going strong. Planted at the end of my driveway in a western aspect. Gets blasted in the summer heat from the asphalt, takes the drying winter winds well.


On Jan 25, 2006, Gabrielle from (Zone 5a) wrote:

I have it along a chainlink fence to hide the fence; it is the perfect height to provide a bit of privacy, but still be able to visit. I have it in a fair amount of shade under a maple tree, so it doesn't get as tall. My information says it is hardy in zones 4-9. Blooms June-July in my garden.


On Dec 10, 2005, bigcityal from Appleton, WI (Zone 5a) wrote:

This is a nice looking grass that stays in place and tolerates a wide variety of conditions.


On Aug 26, 2004, tcfromky from Mercer, PA (Zone 5a) wrote:

This upright, arching grass grows 2 to 3 feet round with showy flower spikes rising 3 feet above the foliage. Green with red bronze tones turn golden in the fall. Good in meadows and open woodlands - it likes a rich moist sunny location and can tolerate heavy soil and heat with water. Good vertical accent plant.


On Aug 9, 2004, BingsBell from SC, MT (Zone 5a) wrote:

I am adding another positive for this great grass. It is beautiful, tough, early to start each spring and beautiful all winter long until haircut time. I have two beautiful clumps near my pond which is above ground 18 inches for me to sit on to play with the fish and keep my water lilies looking nice. The grasses make it look natural without hiding the pond.

I put this and the "overdam" variety in places all over. It stands by itself well as well as accents other beds. Use it to hide an ugly A/C or give a blank wall or fence some class.


On Sep 10, 2003, cbamrick from Green Bay, WI (Zone 5a) wrote:

This ornamental grass provides much-needed winter interest in my Wisconsin (U.S.) location. Its vertical growth habit provides an interesting backdrop for other plantings while doubling as a living wind barrier when planted in groupings. I am particularly delighted to see the number of stages the seed heads go through. Airy and open with a pink cast to golden and vertical. This has been an excellant performer for me in Green Bay, Wisconsin.