Chasmanthium Species, Indian Woodoats, Inland Sea Oats, Northern Sea Oats, River Oats

Chasmanthium latifolium

Family: Poaceae (poh-AY-see-ee) (Info)
Genus: Chasmanthium (chas-MAN-thee-um) (Info)
Species: latifolium (lat-ee-FOH-lee-um) (Info)
Synonym:Uniola latifolia


Ornamental Grasses and Bamboo

Water Requirements:

Average Water Needs; Water regularly; do not overwater

Sun Exposure:

Sun to Partial Shade


Grown for foliage


Provides Winter Interest

Foliage Color:



24-36 in. (60-90 cm)


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:

Grow outdoors year-round in hardiness zone



Bloom Color:

Chartreuse (yellow-green)

Bloom Characteristics:

Flowers are good for drying and preserving

Bloom Size:

Unknown - Tell us

Bloom Time:

Mid Summer

Late Summer/Early Fall

Other details:

Soil pH requirements:

6.1 to 6.5 (mildly acidic)

6.6 to 7.5 (neutral)

Patent Information:


Propagation Methods:

By dividing the rootball

From seed; direct sow outdoors in fall

Self-sows freely; deadhead if you do not want volunteer seedlings next season

Seed Collecting:

Allow seedheads to dry on plants; remove and collect seeds


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

Birmingham, Alabama

Huntsville, Alabama(2 reports)

Morrilton, Arkansas

Redlands, California

San Diego, California

Stockton, California

Denver, Colorado

Lake City, Florida

Niceville, Florida

Pensacola, Florida

Pompano Beach, Florida

Cleveland, Georgia

Cordele, Georgia

Marietta, Georgia

Cherry Valley, Illinois

Coal City, Illinois

Crystal Lake, Illinois

Palatine, Illinois

Peoria, Illinois

Plainfield, Illinois

Urbana, Illinois

Warrenville, Illinois

Ewing, Kentucky

Louisville, Kentucky

Baton Rouge, Louisiana

Denham Springs, Louisiana

Zachary, Louisiana

Baltimore, Maryland

Churchton, Maryland

Takoma Park, Maryland

Marlborough, Massachusetts

Reading, Massachusetts

Dearborn Heights, Michigan

East Tawas, Michigan

Smiths Creek, Michigan

Cole Camp, Missouri

Piedmont, Missouri

Omaha, Nebraska

Reno, Nevada

Dover, New Hampshire

Frenchtown, New Jersey

Mount Laurel, New Jersey

Putnam Valley, New York

Davidson, North Carolina

Elizabeth City, North Carolina(2 reports)

Greensboro, North Carolina

Hayesville, North Carolina

Canton, Ohio

Cincinnati, Ohio

Glouster, Ohio

Lynchburg, Ohio

Eufaula, Oklahoma

Hulbert, Oklahoma

Jay, Oklahoma

Tulsa, Oklahoma

Portland, Oregon

Brookhaven, Pennsylvania

Downingtown, Pennsylvania

Murrysville, Pennsylvania

New Freedom, Pennsylvania

North East, Pennsylvania

Philadelphia, Pennsylvania

Pittsburgh, Pennsylvania

Spring Grove, Pennsylvania

Conway, South Carolina

Myrtle Beach, South Carolina

Morristown, Tennessee

Arlington, Texas(2 reports)

Austin, Texas(3 reports)

Belton, Texas

Boerne, Texas

De Leon, Texas

Fort Worth, Texas

Helotes, Texas

Lindale, Texas

Lipan, Texas

Missouri City, Texas

New Braunfels, Texas

New Caney, Texas

Santo, Texas

Spicewood, Texas

Salt Lake City, Utah(2 reports)

Leesburg, Virginia

Springfield, Virginia

Battle Ground, Washington

Cherry Grove, Washington

Dollar Corner, Washington

Lewisville, Washington

Meadow Glade, Washington

Venersborg, Washington

Liberty, West Virginia

La Crosse, Wisconsin

Westfield, Wisconsin

show all

Gardeners' Notes:


On Apr 7, 2021, krainieri from Putnam Valley, NY (Zone 5b) wrote:

It does not survive winters in my zone 5 garden. I loved the way it looked next to my waterfall, and it never spread. My soil is clay, so I guess that is what kept it behaved. I may plant it again, even if it does not survive the winter.


On Dec 15, 2018, JennysGarden_TN from Collierville, TN wrote:

I grow Northern Sea Oats for its ornate seedheads. I don't do anything to it but just let it grow on its own. It returns every season in the same spot and self sows readily in my zone 7b garden.


On Oct 30, 2015, KatrinaVanTassel from Arlington, TX (Zone 8a) wrote:

Inland Sea Oats - is what we call them here.
Growing in a mostly shaded area along the banks of Rush Creek in Arlington, Texas among the Equisetum (Horsetail rushes).
This was easy for me to pull up in the sandstone soil along the creek area after a heavy rain.
Beautiful seed heads in October here. As cut flowers, they lasted a long time in my kitchen. They did not shed seeds all over the table.


On Oct 29, 2015, coriaceous from ROSLINDALE, MA wrote:

A handsome plant in the right context, especially in a meadow or woodland edge where there's a lot of room. The seeding scapes are very attractive in cut flower arrangements, and dry well.

This is among the most shade-tolerant of grasses.

However, I've found it to self-sow aggressively in the border. The seedlings do not pull up intact and need a tool to extract them. They also spring up in the crowns of other perennials. I long ago decided that it wasn't worth all the extra work, and removed it from my borders.

Armitage says this species is hardy to Z3.


On Jul 30, 2015, Rickwebb from Downingtown, PA wrote:

A good-looking meadow or prairie grass of eastern and central North America. I planted a few by a fence in my backyard and they are doing well, for they are easy care and strong. However, they do self-sow around and I have to remove seedlings and young plants from a few areas of my yard, and those young plants are resistant to pulling and digging. This species can be bought at both conventional and native nurseries. It is not a big shopping item for most landscapers and gardeners, but some are sold each year at many nurseries.


On Nov 1, 2013, Phellos from Port Vincent, LA wrote:

I first saw this growing under neath some sideways growing shade making river birch trees along the banks of the Amite river here in Louisiana. I collected some seeds and plan to try growing this in my 'river garden' along my willow and cottonwood trees.


On Jul 27, 2013, Arthur55 from Decatur, IL wrote:

I am so sorry I planted Northern Sea Oats! They are coming up EVERYWHERE! I have found the plants to be difficult to pull because of extensive root systems, so for several years I have removed all seed heads, hoping to stop them from spreading. They can apparently send roots long distances, because I find them 15 feet away on the other side of a concrete patio! I REALLY dislike Northern Sea Oats!


On Jul 30, 2012, SoooSirius from Municipality of Murrysville, PA wrote:

I have both positives and negatives about this plant. As others have said, it does reseed freely. However, it does tolerate growing in a difficult environment - along a winter-salted Pennsylvania street. It is lush no matter how dry the weather, and for me provides some measure of privacy and sound-deadening along said street. It is also growing in clay/rock subsoil, the junk the gas company left behind when they filled in the trench after installing new line. Chasmanthium has provided winter interest in an area that would otherwise be bare in the winter. I would recommend that if you do want to cut or pull this plant that you wear good, thick, garden or work gloves, because the edges of the leaves and stems are like razors on your hands if you attempt to pull them. I agree that it does be... read more


On Nov 4, 2010, oldgal67 from London, ON,
Canada wrote:

This pretty - so far non-invasive - plant has been growing happily in shade in an herbaceous border in my garden in Southwestern Ontario (Canada - Zone 5) for two years now. I cut the dry heads in early November for indoor decoration so self-seeding hasn't so far been a problem. - in fact I would be happy to see it spread itself about a bit more than it does. It has remained in the slowly growing clump I planted two springs ago without showing any signs of becoming rampant......I may live to eat those words, of course ;o)


On Jun 7, 2009, Juniper99 from Charlottesville, VA wrote:

My experience combines the positive and negative others have posted. Placement of this wonderful species is crucial. I originally planted it, without research, in my carefully controlled, moist woodland shade garden along my front path. The seedlings were simply overwhelming, and as Victor accurately states, if you don't catch the small seedlings in time, it is very difficult to pull and becomes a serious problem.

I've a new garden, and my woodland shade garden is now a much wilder place in my back yard. I'm planting this species today and eager to see its spangliness run wild, adding to the much-needed native diversity of my suburban lot.


On Apr 30, 2008, CurtisJones from Broomfield, CO (Zone 5b) wrote:

From your friends at Botanical Interests, inc.: An ornamental and U.S. native grass, Northern Sea Oats has clumping foliage that is reminiscent of bamboo leaves. A relative of true oats, its nodding seed heads dance in the slightest wind. As temperatures cool in autumn, its foliage and seed heads turn a richy, coppery red then turn to bronze as winter draws near. Leave them standing for their fall beauty or cut them for dried flower arrangements. Plants started in early spring will produce seed heads the first year. (Cut back in fall after seeds heads appear to prevent spreading if it is a problem in wet soil areas.) Perennial in zones 4-9.


On Jun 14, 2007, CodyMody7890 from Reno, NV (Zone 6a) wrote:

this grass is amazingly bamboo- like and has BEAUTIFUL flowers that turn brown when cold /fall arrives makes a very cool quakish sound when wind blows ! attractive year round and extremely hardy ! iv learned it likes part to full shade more than sun !


On May 21, 2007, soulgardenlove from Marietta, GA (Zone 7b) wrote:

Okay.. it's not "invasive" but I have moved it two times. If you plant it amongst ground covers, just imagine if someone threw a handful of grass seeds throughout.. Nope, not a problem to pull up, but you just have to do it strand by strand while not taking up your desired plants. The seeds are pretty and I do like the way they look.. it just needs to be in the right place. It is easily divided and shared. Just dig up the clump and saw in as many new plants as you want. Susan


On Apr 18, 2007, WUVIE from Hulbert, OK (Zone 7a) wrote:

When planted in the right location to do as it will, it
makes a fabulous display.

However, I, like others mentioned, made the mistake
of planting it among my normal garden environment.
I am still digging it out of the location.

Otherwise, I love watching the little spangles dangle.



On Jul 21, 2006, princessnonie from New Caney, TX (Zone 8b) wrote:

Inland Seaoats is native in this part of Texas. ( Pineywoods, 40 miles north of Houston ) It's foliage is similar to bamboo and the seedheads are very showy.
In this area, with no supplamental water and in full sun, it spreads rather aggressively and is hard to get rid of without the use of herbicides..
I prefer it in its native habitat near a shady creek bank away from flower beds.


On May 15, 2006, victorgardener from Lower Hudson Valley, NY (Zone 6b) wrote:

Horrible re-seeder here. Did not exhibit this for about five years. Now it is everywhere and contrary to one of the other reviews, it is NOT easy to remove unless you spot it when it first sends up a teeny shoot. After that, it gets very fibrous anchors of roots. This and Eupatorium rugosum 'Chocolate' are the worst offenders I have in my garden. Would not wish them on anyone.



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

I really like the seedheads on this; they look as though they have been pressed. I keep thinking of ways to make a bookmark out of them and some day I will. Last fall I cut some after they had dried brown, but the blades were still green. The blades dried with the green color. I made a bit of a decoration in a vase with it and Feather Reed Grass, and it lasted and looked really nice. I'm not into dried flowers. It's not that I don't like them, it's just not my skill. So if I can do it, anyone can.

I do recommend deadheading this unless you want them coming up everywhere. Blooms June - September in my garden.


On Jul 27, 2004, Toxicodendron from Piedmont, MO (Zone 6a) wrote:

I am fortunate to have great quantities of this native grass growing along my creek and it's tributaries. It thrives in full shade, and thin rocky soil. I dug one up and put it in a flower bed once, and then I had to dig out seedlings for about 3 years after that, so I don't recommend placing them in a formal planned area. Last year I saw some plants for sale in 2 gallon pots.
If you want to dry them for arrangements and would like them to remain green, pick them in August. They last for years. Of course, they are beautiful all winter if left standing where they grow, but they will gradually lose most of the seeds by spring.


On Jul 26, 2004, henryr10 from Cincinnati, OH (Zone 6b) wrote:

I first ran into this grass about 5 years ago at Cox Arboretum in Dayton, OH.

After describing our shady conditions they recommended Northern Sea Oats.

It absolutely is the grass for partial shade/shade,
3' tall w/ 42" seed heads thick and lush.
I've seen Badseed's Oats, in her full sun conditions, and see no difference.

It IS politely invasive.
Because the seeds are so heavy it's more of a creeping invasion though.
Not much running from roots.
As stated above very easy to control.

The easiest way to propagate is just shake the dried seed heads over the area you'd like to cultivate.

Try in in a container.
It makes an easy, instant, tall filler for empty areas.

... read more


On Dec 4, 2003, greenjeans1 wrote:

This is a very easy to grow grass. Though it loves to reseed I didn't find it invasive. The dried seed heads turn bronze and make wonderful dried decorations.


On May 30, 2002, gardenwife from Newark, OH (Zone 5b) wrote:

This is one of my favorite ornamental grasses. The seed heads turn a lovely russet color in the fall and really augment the garden. This spring I had two small starts of it beneath the two main clumps I put in two years ago. It definitely self-seeded last year, but it is by no means invasive.


On May 30, 2002, Wingnut from Spicewood, TX (Zone 8b) wrote:

These are also native to Central Texas, found along spring-fed creeks. I just love the graceful arcs of the stems holding the seed pods! They're also called River Oats, Inland Sea Oats, Broadleaf Woodoats, Sea Oats, Northern Oats and Indian Woodoats.


On Aug 31, 2001, smiln32 from Oklahoma City, OK (Zone 7a) wrote:

This clump-forming, upright, ornamental grass is a Missouri native plant which typically grows 2-5' and most often occurs in rich woods or rocky slopes along streams and on moist bluffs. This grass is perhaps most distinguished by the flat, drooping seed heads which hang in terminal clusters on thread-like pedicils from slightly arching stems. Seed heads will flutter when caressed by even the softest of breezes. Seed heads emerge green but turn purplish bronze by late summer. Bright green leaves (5-9" long) turn a coppery color after frost and eventually brown by winter. Excellent for dried flower arrangement


On Aug 9, 2001, Badseed from Hillsboro, OH (Zone 6a) wrote:

This grass is very easy to grow from seed or can be divided. I grow it for the showy seed heads, that work very well for dried arrangements. It does self seed, but not enough to be a nuisance. Seedlings are easy to move.