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Acorus calamus (Sweet Flag)

Sweet Flag, Calamus, Flagroot, Sweet Cane, Sweet Grass, Sweetroot, Sweet Rush, Acorus americanus, Acorus calamus var. americanus

Acorus calamus, Sweet Flag, Calamus, Flagroot, Sweet Cane, Sweet Grass, Sweetroot, Sweet Rush, Acorus americanus, Acorus calamus var. americanus

Ideal for wet areas, Acorus calamus (Sweet Flag) is a spreading, marginal aquatic perennial forming a tuft of erect, sword-shaped, bright green leaves adorned with one slightly wavy edge and a prominent midrib. In late spring, this plant bears inconspicuous greenish-yellow flowers in finger-like inflorescences, 2-4 in. long (5-10 cm), which give way to tiny, reddish berries. Both the crushed foliage and rootstocks have a pleasant aromatic fragrance. A great choice for naturalizing, Sweet Flag is quite versatile in the garden and makes a decorative foliage accent in water gardens and around ponds.

  • Grows easily about 24-30 in. tall (60-75 cm) and 18-24 in. wide (45-60 cm). This plant will slowly spread over time by rhizomes to form a dense ground cover. It is not considered invasive.
  • Enjoys full sun to part shade and thrives in medium to wet soils. Grows well in both boggy conditions including shallow standing water to 9 in. deep (22 cm). Do not let the soil dry out. Afternoon shade is appreciated in hot summer climates.
  • This is a graceful plant for water gardens, rain gardens, stream or pond margins, and bogs.
  • Low maintenance, this plant is generally disease and pest free.
  • Propagate by rhizome division at the beginning of the growing season. Pot up and plant out only when fully established. Divide every few years to prevent congestion.
  • Introduced into North America for medicinal, ornamental, and other purposes. Sweet Flag is native to India, Central Asia, and probably Eastern Europe.

 

Requirements

Hardiness 4 - 10
Heat Zones 2 - 11
Climate Zones 2, 2A, 2B, 3, 3A, 3B, 4, 5, 6, 7, 8, 9, 10, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24
Plant Type Aquatic Plants, Ornamental Grasses, Perennials
Plant Family Acoraceae
Genus Acorus
Common names Sweet Flag, Sweet Grass, Calamus
Exposure Full Sun, Partial Sun
Season of Interest Spring (Late)
Summer (Early, Mid, Late)
Fall
Height 2' - 3'
(60cm - 90cm)
Spread 1' - 2'
(30cm - 60cm)
Spacing 24" (60cm)
Maintenance Low
Water Needs High
Soil Type Clay, Loam, Sand
Soil pH Acid, Alkaline, Neutral
Soil Drainage Poorly Drained
Characteristics Showy
Native Plants United States, New Jersey, New Hampshire, New York, Vermont, Rhode Island, Pennsylvania, Maine, Maryland, Southeast, Pacific Northwest, Alaska, Rocky Mountains, Midwest, Northeast, Ohio, North Dakota, Iowa, Wisconsin, Illinois, Nebraska, Minnesota, Michigan, Indiana, South Dakota, Washington, Idaho, Virginia, Montana
Tolerance Wet Soil
Garden Uses Bog Gardens, Ground Covers, Ponds And Streams, Rain Gardens, Water Gardens
Garden Styles Informal and Cottage
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Alternative Plants to Consider

Acorus gramineus ‘Ogon’ (Golden Variegated Sweet Flag)
Acorus calamus ‘Variegatus’ (Variegated Sweet Flag)

Recommended Companion Plants

Hamamelis x intermedia ‘Pallida’ (Witch Hazel)
Aster dumosus ‘Sapphire’ (Bushy Asters)
Aconitum carmichaelii ‘Arendsii’ (Monkshood)
Primula japonica (Japanese Primrose)
While every effort has been made to describe these plants accurately, please keep in mind that height, bloom time, and color may differ in various climates. The description of these plants has been written based on numerous outside resources.
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Requirements

Hardiness 4 - 10
Heat Zones 2 - 11
Climate Zones 2, 2A, 2B, 3, 3A, 3B, 4, 5, 6, 7, 8, 9, 10, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24
Plant Type Aquatic Plants, Ornamental Grasses, Perennials
Plant Family Acoraceae
Genus Acorus
Common names Sweet Flag, Sweet Grass, Calamus
Exposure Full Sun, Partial Sun
Season of Interest Spring (Late)
Summer (Early, Mid, Late)
Fall
Height 2' - 3'
(60cm - 90cm)
Spread 1' - 2'
(30cm - 60cm)
Spacing 24" (60cm)
Maintenance Low
Water Needs High
Soil Type Clay, Loam, Sand
Soil pH Acid, Alkaline, Neutral
Soil Drainage Poorly Drained
Characteristics Showy
Native Plants United States, New Jersey, New Hampshire, New York, Vermont, Rhode Island, Pennsylvania, Maine, Maryland, Southeast, Pacific Northwest, Alaska, Rocky Mountains, Midwest, Northeast, Ohio, North Dakota, Iowa, Wisconsin, Illinois, Nebraska, Minnesota, Michigan, Indiana, South Dakota, Washington, Idaho, Virginia, Montana
Tolerance Wet Soil
Garden Uses Bog Gardens, Ground Covers, Ponds And Streams, Rain Gardens, Water Gardens
Garden Styles Informal and Cottage
How Many Plants
Do I Need?
Not sure which Acorus (Sweet Flag) to pick?
Compare Now

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