+-----------------------------------------------------------------------+
| ## sweet flag {#sweet-flag .Title-Header}                             |
+-----------------------------------------------------------------------+
| *Acorus calamus* L.                                                   |
+-----------------------------------------------------------------------+
| Plant Symbol = ACCA4                                                  |
+-----------------------------------------------------------------------+

*Contributed by: USDA NRCS Rose Lake Plant Materials Center*

##### Alternate Names {#alternate-names .Header-3}

##### Calamus

##### 

##### Uses

Cultural Primarily, sweet flag is or was known by the American Indian
tribes and early settlers for its medicinal value. Although the
preparation of this species and the ailments it treats vary somewhat
among the tribes, rhizomes are the most commonly used part.

*Wildlife* Sweet flag provides habitat for waterfowl. Muskrats eat the
rhizomes and wood ducks consume the seed.

##### Status {#status .Header-3}

Please consult the PLANTS Web site and your State Department of Natural
Resources for this plant's current status (e.g. threatened or endangered
species, state noxious status, and wetland indicator values).

##### Description {#description .Header-3}

Sweet flag is a perennial, rhizomatous, iris-like herb. The erect,
sharp-pointed, sword-shaped leaves fan-out from a pinkish base and grow
to 5 feet in length. The midvein is usually off-center. Cut or bruised
leaves produce a sweet, tangerine-like scent. The flower stem, or scape,
arises from the base of the outer leaves. Although resembling a leaf,
the scape is triangular in cross section. A long, erect bract, or
spathe, extends beyond the scape. A single, cylindrical 2 to 4-inch
spike, or spadex, angles upward at this union. The slightly curved
spadix is crowded with small yellowish-green to brown flowers that
appear from May to July. Sweet flag has thick, creeping rhizomes with
brownish exteriors and white, fleshy
interiors.![](media/image2.wmf){width="2.5409722222222224in"
height="3.376388888888889in"}

##### Adaptation and Distribution {#adaptation-and-distribution .Header-3}

Sweet flag is irregularly circumboreal. In North America it is found
from Nova Scotia and Quebec to Minnesota, Alberta and Eastern
Washington, south to Florida, Texas and Colorado on wet soils and
shallow water in ditches, marshes, river edges and ponds. It prefers
full sun and a pH range from 5 to 7.

For a current distribution map, please consult the Plant Profile page
for this species on the PLANTS Website.

#####  {#section-1 .Header-3}

##### Establishment {#establishment .Header-3}

Sweet flag can be propagated vegetatively by plant or rhizome division,
and by seed. Vegetative propagation is best completed in the fall or
spring using firm, healthy rhizomes cut into 2- to 4-inch sections.
Plant sections in rich soil 4 - 6 inches deep and 1 foot apart.
Separating individual sprigs from clumped plants is an alternative to
using rhizomes. These should also be transplanted at 1-foot spacings.

![](media/image3.wmf){width="1.9152777777777779in"
height="2.498611111111111in"}

Seed should be planted during the fall or winter in a greenhouse. Fill a
2-inch deep tray with an organic

soil mix, scatter seed sparsely on the surface and press firmly into the
soil. Do not bury further than 1/8 inch deep. Keep soil moist to
saturated. Seed does not require stratification and germinates in less
than 2 weeks. When plants reach 3 to 4 inches transplant into individual
4-inch pots. Pots can be placed in shallow water or irrigated frequently
to maintain very moist to saturated conditions. Transplant outdoors 1
foot apart in the spring. With adequate moisture seed can also be
planted outdoors spring through early summer, or in a cold frame late
summer through fall.

##### Management {#management .Header-3}

Keep soil very moist to saturated; sweet flag does not tolerate droughty
conditions. It grows well under seasonal, shallow inundation, however,
avoid flooding of newly established plants or seeded areas.

Starter fertilizers may be used indoors to improve early growth but are
unnecessary once transplanted outdoors into a rich soil.

The spadix will turn brown as the seed ripens in late summer or early
fall. Seed can be planted immediately or stored in low humidity
refrigeration.

Rhizomes should be harvested for medicinal use in early spring before
new growth, or late autumn. Collect when large and firm, generally after
2 -- 3 years of growth, before becoming hollow.

##### Prepared By/Species Coordinator:  {#prepared-byspecies-coordinator .Header-3}

*Tony Bush, Agronomist*

Rose Lake Plant Materials Center

East Lansing, Michigan

Edited: 05Feb2002 JLK; 30may06jsp

For more information about this and other plants, please contact your
local NRCS field office or Conservation District, and visit the PLANTS
Web site\<[http://plants.usda.gov](http://plants.usda.gov/)\> or the
Plant Materials Program Web site
\<[http://Plant-Materials.nrcs.usda.gov](http://Plant-Materials.nrcs.usda.gov/)\>

*The U.S. Department of Agriculture (USDA) prohibits discrimination in
all its programs and activities on the basis of race, color, national
origin, sex, religion, age, disability, political beliefs, sexual
orientation, and marital or family status. (Not all prohibited bases
apply to all programs.) Persons with disabilities who require
alternative means for communication of program information (Braille,
large print, audiotape, etc.) should contact USDA\'s [TARGET
Center](http://www.usda.gov/oo/target.htm) at 202-720-2600 (voice and
TDD).*

*To file a complaint of discrimination write USDA, Director, Office of
Civil Rights, Room 326-W, Whitten Building, 14th and Independence
Avenue, SW, Washington, DC 20250-9410 or call 202-720-5964 (voice or
TDD). USDA is an equal opportunity provider and employer.*

*Read about [Civil Rights at the Natural Resources Convervation
Service](http://www.nrcs.usda.gov/about/civilrights/).*