Nassella Species, Silky Thread Grass, Mexican Feather Grass, Mexican Needle Grass, Pony Tails

Stipa tenuissima

Family: Poaceae (poh-AY-see-ee) (Info)
Genus: Stipa (STEE-pa) (Info)
Species: tenuissima (ten-yoo-ISS-ee-muh) (Info)
Synonym:Stipa tenuissima


Ornamental Grasses and Bamboo

Water Requirements:

Average Water Needs; Water regularly; do not overwater

Sun Exposure:

Full Sun


Grown for foliage


Foliage Color:

Unknown - Tell us


24-36 in. (60-90 cm)


15-18 in. (38-45 cm)


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)

USDA Zone 10a: to -1.1 C (30 F)

USDA Zone 10b: to 1.7 C (35 F)

Where to Grow:

Unknown - Tell us



Bloom Color:


Bloom Characteristics:

Unknown - Tell us

Bloom Size:

Unknown - Tell us

Bloom Time:

Late Spring/Early Summer

Mid Summer

Other details:

May be a noxious weed or invasive

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

From seed; direct sow outdoors in fall

From seed; stratify if sowing indoors

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

Properly cleaned, seed can be successfully stored


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

Gaylesville, Alabama

Chino Valley, Arizona

Kingman, Arizona

Maricopa, Arizona

Phoenix, Arizona

Alameda, California

Atwater, California

Brentwood, California

Cerritos, California

Chatsworth, California

Chula Vista, California

Cloverdale, California

Concord, California

Eureka, California

Fremont, California

Fullerton, California


Knights Landing, California

Los Angeles, California(2 reports)

Merced, California

Murrieta, California

Oak Park, California

Oakdale, California

Redlands, California

Riverside, California

Sacramento, California

Salinas, California

San Clemente, California

San Diego, California

South Pasadena, California

Sunland, California

Woodland, California

Denver, Colorado

Englewood, Colorado

Grand Junction, Colorado

Okeechobee, Florida

Cordele, Georgia

Boise, Idaho

Grayslake, Illinois

Ewing, Kentucky

New Orleans, Louisiana

Pownal, Maine

Pikesville, Maryland

Rushford, Minnesota

Las Vegas, Nevada

Pahrump, Nevada

Manchester, New Hampshire

Clovis, New Mexico

Las Cruces, New Mexico

Los Lunas, New Mexico

Roswell, New Mexico

Riverhead, New York

Statesville, North Carolina

Wake Forest, North Carolina

Winston Salem, North Carolina

Enid, Oklahoma

Hulbert, Oklahoma

Coos Bay, Oregon

Portland, Oregon(2 reports)

Salem, Oregon

Drexel Hill, Pennsylvania

Ponce, Puerto Rico

Cinisi, Sicily(2 reports)

Columbia, South Carolina

Greenville, South Carolina

Okatie, South Carolina

Knoxville, Tennessee(2 reports)

Memphis, Tennessee

Arlington, Texas

Austin, Texas(4 reports)

Burleson, Texas

Carrollton, Texas

Dallas, Texas

Dripping Springs, Texas

Humble, Texas

Irving, Texas

Kennard, Texas

Magnolia, Texas

Midland, Texas

Midway, Texas

Plano, Texas(2 reports)

Richmond, Texas

San Antonio, Texas(2 reports)

Spring Branch, Texas

Ogden, Utah

Alexandria, Virginia

Arlington, Virginia

Springfield, Virginia

Bellevue, Washington

Blaine, Washington

Seattle, Washington

Vancouver, Washington

Twin Lakes, Wisconsin

show all

Gardeners' Notes:


On Apr 23, 2020, arPie47 from Plano, TX,
United States wrote:

The previous owners of our house left a couple of clumps of this in a pot, and there had been a drought, so they appeared dead. We were too busy for awhile to deal with it, but left it in an area where it didn't get rain or much light, intending to salvage the pot later. About 2 years later there was a storm that was windy enough to blow quite a bit of rainwater into that pot, and the grass came to life, much to our surprise. It was pretty, so we planted it. Now in its 4th season in the flower bed it has choked out everything else except some red yuccas, and it's beginning to invade in other areas. We would like to let it continue in an otherwise dead zone along the driveway, but are wondering how to remove it from other places. It's about as tenacious a plant as we've seen in this north T... read more


On Jun 5, 2019, MargCat from Bradley, CA wrote:

This grass is taking over my yard. How do I control it?


On Oct 8, 2018, MtnGardener from Longmont, CO (Zone 5a) wrote:

In zone 4, at 5000' altitude in clay soil I was unable to keep this plant alive. It does not seem to be able to withstand the wind and the very dry conditions. Would recommend treating this as an annual in similar zones.


On May 2, 2017, Mitchella from Pownal, ME (Zone 5b) wrote:

Interesting that nearly all of the comments are from very warm zones, where this plant is certainly invasive. But I live in zone 5, grow it like an annual in a pot, and it's gorgeous. It never reseeds and in fact rarely has time to bloom. I recommend it for zone 5b and colder, but for warmer zones please consider the consequences of its rapid spread. Even if the seedlings are "easy to pull" there will be no one to pull them when it escapes to natural areas, as it surely will sooner or later.


On Mar 1, 2016, coriaceous from ROSLINDALE, MA wrote:

Native to west Texas, New Mexico, Mexico, Chile, and Argentina, this species has been deemed an emerging threat to natural habitat in California (where it is not native), where it has escaped cultivation and is well on the way to becoming the next Pampas grass.

This is a weed in its native range where land is disturbed as by overgrazing. It forms indigestible balls in the stomach of stock and, if they are forced to graze the infested pasture, they may lose weight and die, as Nassella tenuissima has a high fibre content and a low nutritive value.

This is a prohibited species in Australia, where it has naturalized despite being quarantined.

It has also naturalized in New Zealand, South Africa, France, and Italy.

... read more


On Aug 28, 2014, elden from Redondo Beach, CA (Zone 10b) wrote:

I cant stand this stuff... my neighbor has this planted everywhere and it killed all the stuff in my garden beds and now my turf is mixed with Mexican feather grass. Here's a video I made showing how invasive this can be, it's so frustrating.


On May 20, 2014, AunTee from East Oakdale, CA wrote:

PROS: beautiful to watch wave in the wind. Easy to plant, grow and reseed (does on its own) Drought tolerant and great for rocky xeriscapes. SUGGESTION: perfect for large areas or acreages needing soil retention, hillsides, empty lots with poor soil and little irrigation. It'll spread on its own and you'll have to do nothing.
CONS: DO NOT PLANT AROUND POOLS OR PONDS with pumps. The thread will blow into water and clog up filters. It'll stick to your clothing, gloves, hair. DO NOT plant if you have dogs or cats that like to sniff around everything. Our little Terrier mix got one or two of the threads up her nose and that began a 24-hour sneeze fest for her. It'd stop for awhile then start up again. It exhausted her and she didn't know what was going on. The next day we took her to ou... read more


On May 19, 2014, Lazygardener2 from Los Angeles, CA wrote:

I planted three small plants along a border, and I now have at least one dozen volunteers. What is interesting is that this grass seems to preferentially pop up along the edges of our garden paths. Although I had wanted thyme to grow around my rock path, it just refused to tolerate the heat, and died out. So, although I had a different vision, stipa has filled in and requires much less water than most plants, which is great since we are in a drought. My Yellow Lab does not mind it at all, and we have not had any health problems with her due to this plant. My advice: this will work well IF you want a fairly natural, windswept look, but it will pop up everywhere. That said, it is very easy to pull out from places it is not wanted, and it fulfills my basic gardening philosophy: plants have to... read more


On Jan 10, 2014, BeatenObamacare from Albuquerque, NM wrote:

Your neighbors will hate you for planting Mexican Feather Grass, or Thread Grass. It will be growing all over the place-and is not at all easy to pull up in the dry alkaline soils we have.
It may wave in the wind beautifully, but do you really want it everywhere in the landscape?


On Jan 26, 2013, Dogopr from Ponce, PR wrote:

I'm in zone 13a (as maybe I'm a daredevil but I sow a few of those a few months ago -maybe mid December- and they are germinating!!!! Hope to succeed!


On May 21, 2012, hampson from Kingman, AZ (Zone 8b) wrote:

I planted more than one in a perennial bed that gets watered regularly. It's lovely, but it sure does reseed! I pull and hoe out the seedlings from my beds, but my husband lets many seedlings go in his naturalized dry, desert areas. It's pretty easy to pull up and worth the effort, but I remove as much seed fluff as I can now and often shear the seed heads off. Absolutely beautiful to watch in the wind.


On Jun 23, 2011, romandoguinn from Albany, CA (Zone 10a) wrote:

This plant makes me furious.

This is the nicest thing I can say.

The landlord of the apartments next door had landscapers plant half a dozen of these along our shared pathway. The metric ton of seed fluff that accumulates along my edging looks like handfulls of mangey dog hair. I end up sweeping it up multiple times daily. If they were my plants I'd remove them asap. And am thinking about it regardless, between you and me.

These have been planted less than 6 months. I'm literally afraid of the volunteers I'll encounter in the future.


On Jan 22, 2011, dvangogh from Los Angeles, CA (Zone 10b) wrote:

This is a beautiful grass, though invasive as others have mentioned. The movement of the plant as a light breeze catches it is just beautiful to watch. Very calming and can add a dynamic touch to your garden.


On Jul 16, 2010, justdigin from Merced, CA (Zone 9a) wrote:

Although it reseeds freely as others have mentioned, I find the seedlings easy to pull out. Even the larger ones can be removed or transplanted without much effort. If you are trying to maintain a very neat landscape, this plant is probably going to drive you crazy. If you like a more naturalized look as I do, you may really like it. It fills in the areas around my other plants, but doesn't choke them out. It reminds me of the California coast, which is the look I am going for in our front yard. As others have said, don't plant where your dog might get into it.


On Jun 28, 2010, 1e9l3h7 from Rio Rancho, NM wrote:

plant grows well here ,'west mesa in albuquerque. no problem with reseeding have divided to get four new plants. Looks good in winter.


On Jun 3, 2010, mwdallas from Carrollton, TX wrote:

I live in the Dallas, TX area & planted one in 2007. I now have several that I've re-potted from baby plants. My main plant did die after an awful frost last year, but left its babies and I was thrilled. YES, they do re-seed very easily but are so easy to pull out when very little if not wanted. I don't consider them invasive for this reason. I love watching the gentle peaceful swaying in the wind of this plant. I've given several away. I have only 3 in the ground and several in pots right now.


On Mar 11, 2010, zsir from Chula Vista, CA wrote:

I put one of these in a small backyard garden because I liked it visually and the way it moves in the wind. I thought it a harmless carefree addition. You'd think it ideal for Xeriscape or rock gardens. However it reseeds like crazy, and this from just one plant. Put 4 -5 or more in and you will have alot of extra work on your hands come early spring. I'll be sure to research before I try any other ornamental grasses. Proceed with caution with this choice.


On Jun 15, 2009, NicoleJ from San Clemente, CA wrote:

My dog chased her tennis ball into an area of our yard where this plant is proliferating. She had several of the hairs stuck in her eyes and they caused her eye to swell shut. It has also somehow affected her jaw and given her a form of "lock jaw" and the veterinarian thinks she may have contracted tetanus from it. I am pulling it out and would not recommend it in a yard with active dogs.


On May 20, 2009, anelson77 from Seattle, WA wrote:

beautiful sensuous grass which adapts to a variety of conditions, sun, part shade, dry poor soil. Reseeds and spreads but not difficult to control.


On May 6, 2009, paires from Sedona, AZ (Zone 9b) wrote:

My landscape designer suggested this grass, and I think it is really lovely to watch blowing in the wind. However, it was planted next to my swimming pool, and the seed threads pass through my filter baskets and clog my impeller. I have to clear it out daily, even though I go out every morning and strip as much seed off of the plants as I can. I'll probably have to dig up the plants, and hope they don't sprout on the other side of the back yard wall, in the desert.


On Jun 21, 2008, lonediver from Maricopa, AZ (Zone 9b) wrote:

I will agree with most of the aforementioned statements , durable , beautiful and so on . But I also see that it is labeled as INVASIVE . I capitalize that with good reason . Here in the southwest desert and this is not a native plant . I planted 6 of them and now have had 100's of them all over my property (4 acres ) in an area that recieves less than 10 inches of rainfall a year and this stuff is sprouting up with no irragation . More so in areas that does . Once released it will scatter more than likely and add more fuel to already disastrous wildfires .


On May 7, 2008, TrishaG from Englewood, CO (Zone 5b) wrote:

This grass looks like a clump of hair, dancing in the breeze. Soft green in spring, then turns a soft beige in the hot summer, and I leave it uncut in winter to provide interest. It does re-seed fairly heavily, but unwanted volunteers are easily pulled. I grow it pretty dry in my xeriscape area, in clay loam low in organic material. Survived a dry cold winter quite well. The description says 24-36" height -- I've never seen it get taller than 6-8", even at the Denver Botanic Gardens. Maybe because we grow it dry in the Rockies?


On May 7, 2008, SWNMgardener from Las Cruces, NM wrote:

I really loved the look of this grass in our landscape. It grows quite well in the desert southwest with some irrigation. But beware if you have puppies that like to grab at anything that moves. One of our puppies grabbed at some seeds/feathers that had fallen to the ground and nearly choked while trying to swallow them. We were unable to find any in it's mouth to remove, so I don't believe it had very much.
Also, this plant is a favorite of jackrabbits, so it's best grown behind a fenced area or chicken wire.


On Apr 12, 2008, DonnaMack from Elgin, IL (Zone 5a) wrote:

I grow this grass in a pot, and bring it in for the winter. I also start it in the ground, dig it up, and bring it into the house to overwinter. That way, I get the lovely bloom although my season is too short for it to bloom outdoors. Last year's pot plant is blooming no - in early April, in my sunroom.


On Mar 3, 2007, RHSJONES from Grand Junction, CO wrote:

this was one of the first plants I put in my new garden because it is so beautiful in the wind and I am in a windy area. It did very well even through our cold winter but I fear I have baby's all around it! will try and transplant them to my other garden. did well in composted heavy clay and was watered by drip only once a week even in hot weather.


On Jun 7, 2006, htop from San Antonio, TX (Zone 8b) wrote:

Other common names for this grass that is native to California, New Mexico, Texas, Mexico, and Argentina: ponytail grass, horsetail grass, horse tail grass, hair grass, angel hair grass, angelhair grass, finestem needlegrass

I have grown Mexican feather grass in a large container and did not have a reseeding problem; however, this may be atypical. It appears it will self-sow more prolifically in moist areas and is not as bothersome in dry locations. It mysteriously died sabout 5 years ago. This spring, a new plant emerged in the container in which the old plant had been growing. I am extremely happy that I have been blessed with this gift because I had missed the plant very much after it died.


On Aug 6, 2004, dh1234 from Atwater, CA wrote:

My comment is postive based on growability in the Central Valley of California. The only thing I don't care for, my wife loves it, is it sows itself all over the place. Otherwise a very durable plant.


On Oct 2, 2003, htop from San Antonio, TX (Zone 8b) wrote:

San Antonio, Tx.
One is growing in a huge container and from the top it looks almost like a huge green wig. I bought it at Walmart as a small plant and it has grown quite rapidly. Its blades blow in the wind so gracefully that it provides a soothing effect. It has withstood 22 degree nights in the winter and 108 degrees for 2 days this summer.


On Jul 1, 2002, lupinelover from Grove City, OH (Zone 6a) wrote:

The hardiness of this grass seems to depend on the age. Clumps that have not flowered are much hardier, making this a biennial for me. Usually the clumps that have flowered do not survive the winter.

The flower stalks and seeds are very sticky so that seeding around is very common.

Seeds sprout in mid to late spring outdoors.