The common name for Acorus gramineus 'Ogon' is golden sweet flag. Golden sweet flag originally comes from the wetlands of China, Japan, Korea, India, the Philippines and Thailand.
Initially Acorus gramineus 'Ogon' was assigned to the arum family, which also includes the lily. Nowadays Acorus gramineus 'Ogon' has been assigned to its own family, Acoraceae.
The term "gramineus" means grasslike and refers to the grasslike shape of the leaves.
Acorus gramineus 'Ogon' thrives in boggy conditions. It likes very moist soil or even shallow standing water (about 4 inches (10 cm) deep). This makes it well-suited planting along water edges. It can also grow well in slightly drier areas, though this perennial will be smaller and grow slower there. If it gets too dry, the leaf tips may turn brown. This plant does not have any special soil requirements.
Acorus gramineus 'Ogon' forms a low tuft or mound and purifies the water. It has sturdy, grasslike, aromatic, yellow-green leaves that emit a sweet fragrance when pinched or bruised (hence its common name). Despite its grasslike appearance, the golden sweet flag not a member of the grass family.
The flowers are inconspicuous and have no ornamental value. In our climate in The Netherlands the golden sweet flag hardly ever forms red berries after flowering. It is a very strong plant that has no serious insect or disease problems and is tolerant to salt.
The golden sweet flag is not an invasive plant. It spreads slowly through powerful rhizomes. I tried to contain the Acorus gramineus 'Ogon' with a thin lawn edge, but because the rhizomes are pretty powerful they ‘marched’ over that edge. Because the golden sweet flag spreads slowly it is not necessary put anything around it.
The golden sweet flag is quite hardy. Leaves or leaf tips may die with frost but in spring new leaves will form. You can cut or pull away the dead leaves to enjoy the fresh new growth. In mild regions de golden sweet flag is evergreen.
If the center of the plant thins out, you can dig it up and divide it in spring, replanting the healthy sections.
Attracts bees: no
Characteristic: evergreen
Deer resistant: yes
Exposure: sun/part shade
Flower color: green
Flowering time: June - July
Foliage color: green/yellow
Fragrant flowers: no
Hardiness: -4 ºF/-20 ºC
Height: 16 inches/40 cm
Soil: moist/normal