Common Name: grassy-leaved sweet flag
Type: Herbaceous perennial
Zone: 5 to 8
Height: 0.50 to 1.00 feet
Spread: 0.50 to 1.00 feet
Bloom Time: June to July
Bloom Description: Greenish yellow
Sun: Full sun to part shade
Water: Medium to wet
Suggested Use: Water Plant, Naturalize, Rain Garden
Leaf: Colorful, Fragrant
Tolerate: Erosion, Wet Soil
Easily grown in average, medium to wet soils in full sun to part shade. Grows well in both boggy conditions (including shallow standing water to 3” deep) and consistently moist garden soils. Scorched leaf tips will occur if soils are allowed to dry out. In water gardens, it is planted in containers with up to 3” of water covering the crowns or in wet soils at the edge. Appreciates some relief from hot summer sun (e.g., afternoon shade or filtered sun) when grown in hot summer climates such as the St. Louis area. Slowly naturalizes by spreading roots, but is not too aggressive. Not considered to be reliably winter hardy throughout USDA Zone 5.
A. g. ‘Variegatus’ is commonly called variegated Japanese rush, dwarf sweet flag or grassy-leaved sweet flag. It is a semi-evergreen, marginal aquatic perennial that features grass- to iris-like tufts of narrow, variegated leaf blades (1/4” wide) which are striped with white and green and fan upward to 6-12” tall. It thrives in wet soils and is commonly grown in water gardens and boggy areas as a foliage accent or ground cover. Although it looks like a grass or small iris, it is actually a member of the acorus family. Insignificant, sedge-like flower spikes (2-3” long spadixes without showy spathes) are densely packed with tiny greenish flowers that bloom from late spring to early summer. Flowers give way to tiny fleshy berries. Tufts slowly spread by creeping roots to form a dense ground cover. Foliage is sweetly fragrant when bruised.
No serious insect or disease problems. Scorch will occur if soils are not kept consistently moist
Mass as a ground cover in small areas of water gardens, along streams or ponds, bogs or in moist open woodland gardens. Also effective in rock gardens, border fronts, foundations or as small landscape accents as long as the soil moisture requirements can be met. This plant may be used in the landscape in somewhat the same situations as one might use those species of Carex which prefer sun/part shade.