Fanwort, Washington Grass, Fish Grass
Cabomba caroliniana

Family: Cabombaceae
Genus: Cabomba (kuh-BOM-buh) (Info)
Species: caroliniana (kair-oh-lin-ee-AN-uh) (Info)
Synonym:Cabomba caroliniana var. caroliniana


Ponds and Aquatics


18-24 in. (45-60 cm)


24-36 in. (60-90 cm)


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)

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

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

USDA Zone 11: above 4.5 C (40 F)

Sun Exposure:

Sun to Partial Shade


Parts of plant are poisonous if ingested

Bloom Color:

Pale Pink


Magenta (Pink-Purple)

White/Near White

Bloom Time:

Late Spring/Early Summer

Mid Summer

Late Summer/Early Fall


Grown for foliage

Other details:

Very high moisture needs; suitable for bogs and water gardens

May be a noxious weed or invasive

Soil pH requirements:

4.5 or below (very acidic)

4.6 to 5.0 (highly acidic)

5.1 to 5.5 (strongly acidic)

5.6 to 6.0 (acidic)

6.1 to 6.5 (mildly acidic)

6.6 to 7.5 (neutral)

Patent Information:


Propagation Methods:

By dividing the rootball

Seed Collecting:

Allow seedheads to dry on plants; remove and collect seeds

Properly cleaned, seed can be successfully stored


This plant has been said to grow in the following regions:

Tuscaloosa, Alabama

Chicago, Illinois

Cleveland, Ohio

Austin, Texas

Port Lavaca, Texas

San Antonio, Texas

show all

Gardeners' Notes:


On Feb 15, 2007, frostweed from Josephine, Arlington, TX (Zone 8a) wrote:

Fanwort, Washington Grass, Fish Grass Cabomba caroliniana is Native to Texas and other States.


On Jul 21, 2005, htop from San Antonio, TX (Zone 8b) wrote:

I haven't grown this plant so I am unable to rate it.

Cabomba caroliniana is common aquatic perennial found in the southeastern United States as well as some parts of South America. It occurs from Texas to Florida, north to New England (where it can be found in Connecticut, Rhode Island, Massachusetts and New Hampshire) and west to Kansas. It is also present in Oregon and Washington. It grows so aggressively in some regons that it has been declared a noxious, invasive weed ... see list below). It has become extremely invasive in other parts of the world including Japan, Australia and India. It spreads mainly by stem fragments or rhizomes. The species forms large colonies as floating shoots and new rhizomes arise as axillary branches. These are fragile and easily broken whi... read more


On Aug 26, 2004, jdurha from North Clarendon, VT wrote:

FYI: This is a Class A Noxious Weed in Vermont. Its movement, importation, sale, possesion, cultivation and/or distribution is prohibited with fines upto $1000.00 possible.