Sweet flag - Acorus calamus (Care, Characteristics, Distribution, Images, Toxic)

Sweet flag

Also known as: Muskrat Root, Bitter Pepper Root, Myrtle Flag, Myrtle Root, Pine Root, Sweet Cane, Sweet Grass, Sweet Root, Flag root, Calamus root

Sweet flag (Acorus calamus) is a perennial grass that will grow from 61 to 91 cm tall and 46 to 61 cm wide. It spreads by rhizomes and grows slowly to form a dense ground cover. It thrives in full sun or partial shade and is not invasive. The foliage has a sweet fragrance and in late spring blooms small yellow-green flowers followed by tiny red berries that ripen in fall.

Scientific classification

Species

Sweet flag (Acorus calamus)

Sweet flag and allies

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Toxic to Humans

Toxicity

Perennial

Lifespan

Herb

Plant Type

Spring, Summer

Bloom Time

2 m

Plant Height

45 cm to 60 cm

Spread

Green, Blue, White, Variegated

Leaf Color

3 mm to 4 mm

Flower Size

Green, Yellow, White

Flower Color

Spring

Growth Season

Images of Sweet flag

Distribution of Sweet flag

Distribution Map

Sweet flag is native to regions in Asia, notably in the Indian Subcontinent, Southeast Asia, East Asia, and parts of Russia and Central Asia. This plant has been introduced and is now established across Europe and in some parts of Africa. Sweet flag is also cultivated in many of its introduced ranges, signifying its adaptability to various climates beyond its original habitat.

Native

Cultivated

Invasive

Introduced

No species reported

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Habitat

Ditches, marshes, riversides, ponds

Hemisphere Trend Curve

Northern

Sorthern

Culture

Garden Use

The tall, clumping grasses of the sweet flag can decorate garden borders or the edge of water features, especially when grown in a mass. Its requirement for wet soil makes it perfect for rain gardens and water gardens. The foliage provides showy interest for much of the year when planted as an accent with other plants or as a specimen.

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Cultivars

There are several recognized cultivars of Sweet flag, including the following common varieties :

Variegated sweet flag

Toxicity

Sweet flag is a mildly toxic plant containing alkylbenzenes, leading to potential carcinogenic effects in large doses. The plant's leaves, stem, and flower can irritate sensitive skin, causing rash, redness, and swelling. Ingestion causes severe symptoms like nausea, vomiting, abdominal pain, and CNS depression, especially dangerous for individuals on monoamine oxidase inhibitors.

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Weed Control

Despite the fact that sweet flag is a potentially invasive colonizer of marshland and pond verges, it is only listed as an invasive species in a few US States, namely Alaska, Delaware, and New Jersey. These states class it as an invasive species because of its aggressive growth. This species is also a concern because it contains chemicals that may potentially be toxic to humans. Since sweet flag spreads via an undersoil rhizome root, this plant can be prevented from spreading into unwanted areas by planting it in containers buried in its preferred damp and marshy soils.

How to Control It

Removal: In early autumn or early spring, weeds can be removed with gloves or with the help of tools. The root system must be removed to avoid re-growth.
Chemical control: If the number of weeds is large, glyphosate or diquat can be used for efficient removal. Please note that some areas restrict the use of herbicides in aquatic environments.
Mowing: Weeds are cut twice a year at the end of spring, and weeds can be effectively controlled for two consecutive years. Large areas of weeds can be removed with mowing machines.

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Quickly Identify Sweet flag

Fragrant lance-shaped leaves, bright green, reaching 4 feet (120 cm).

Modest greenish flowers in compact clusters with 6 tepals and stamens.

Inconspicuous berry-like fruit, spongy texture, greenish-yellow, within inflorescence.

Sword-shaped aromatic leaves with wavy margin, red base, and sweet fragrance when crushed.

Thick, fleshy rhizome with cylindrical yellowish-brown stems, supporting upright growth.

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Care Guide for Sweet flag

Once per day

Water

Full sun

Sunlight

5 - 38 ℃

Ideal Temperature

Garden Soil

Soil Type

Water: Sweet flag thrives in wet conditions near water bodies, requiring frequent watering, ideally daily. As a deciduous plant, its water needs decrease during dormancy, but it still benefits from consistently moist soil year-round.

Pruning: Sweet flag features aromatic, sword-shaped leaves and requires minimal pruning, ideally in early spring, to remove dead foliage and manage shape. Pruning promotes vitality and prevents overcrowding. Using sharp, clean tools is crucial for maintaining sweet flag's ornamental health in the garden.

Propagation: Sweet flag is a robust perennial herb favored for its aroma, thriving in wetlands. It propagates effectively through division, where gardeners slice the rhizomatous root system, ensuring each segment has roots and shoots. These divisions can be replanted in moist soil for successful growth.

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