Acorus gramineus 'Ogon'

Tried and Trouble-free Recommended by 3 Professionals
Common Name: grassy-leaved sweet flag
Type: Herbaceous perennial
Family: Acoraceae
Zone: 5 to 9
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
Maintenance: Low
Suggested Use: Ground Cover, Water Plant, Naturalize, Rain Garden
Flower: Insignificant
Leaf: Colorful, Fragrant
Tolerate: Heavy Shade, Erosion, Wet Soil


Easily grown in average, medium to wet soils in full sun to part shade. Grows well in both boggy conditions (including very shallow water) and consistently moist garden soils. Scorched leaf tips will occur if soils are allowed to dry out. Appreciates some relief from hot summer sun (e.g., afternoon shade or filtered sun) when grown in hot summer climates. Slowly naturalizes by spreading roots, but is not too aggressive. May not be reliably winter hardy in the northern areas of USDA Zone 5. Evergreen in warm winter climates.

Noteworthy Characteristics

This grassy-leaved sweet flag cultivar is a dwarf plant which looks like a grass or small iris, but is actually a member of the acorus family. It has insignificant flowers and is grown primarily as a ground cover or accent. Features iris-like tufts of narrow, grass-like, variegated leaf blades (6-12" tall and 1/4" wide) which are striped with yellow and green but primarily appear as yellow. Tufts slowly spread by creeping roots to form a dense ground cover. Foliage is sweetly fragrant. Inconspicuous, sedge-like flower spikes (with spadixes to 3" long) of tiny, densely-packed, greenish-yellow flowers appear in late spring to early summer. Flowers give way to tiny fleshy berries. Commonly called grassy-leaved sweet flag because of the aromatic, grass/iris-like foliage.


No serious insect or disease problems. Scorch will occur if soils are not kept consistently moist to wet.

Garden Uses

Mass as a golden ground cover in small areas of water gardens, along streams or ponds or in moist open woodland gardens. Also effective in rock gardens or border fronts 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.