About

Acorus calamus is a deciduous perennial that thrives in marginal aquatic environments, typically reaching heights of 60 to 90 cm. Its leaves are long, strap-like, and emit a distinctive aroma. In midsummer, the plant produces inconspicuous brown flowers, which can grow up to 7 cm in length, located just below the tips of the leaf-like flowering stems.

About the genus

Acorus comprises deciduous or semi-evergreen perennials that thrive in moist environments. These plants develop clumps of linear or sword-shaped foliage. Near the tips of their central, leaf-like stems, they produce small, spike-like flowers that are not particularly prominent.

Growing conditions

Sunlight
Full sun
Soil type
Clay
Soil pH
Acid, Alkaline, Neutral
Soil moisture
Moist but well-drained, Poorly-drained
Aspect
South-facing, West-facing
Exposure
Exposed, Sheltered
UK hardiness
H7

Plant details

Plant type
Aquatic, Herbaceous Perennial
Habit
Clump forming
Foliage
Deciduous
Height
0.5-1 metres
Spread
0.5-1 metres
Time to full height
2-5 years
Suggested uses
Cottage and informal garden

Care notes

Cultivation
Grow at pond margins in very moist or wet soils in full sun. Grows best in water no deeper than 22cm. Divide every few years to prevent congestion, See bog gardening, pond plants and Ornamental grasses cultivation
Pruning
Cut back after flowering
Propagation
Propagate by rhizome division at the beginning of the growing season. Pot up and plant out only when fully established
Pest resistance
Generally pest-free
Disease resistance
Generally disease-free