Japanese ginger is not a true ginger. It is a perennialherb with ginger-like qualities and is commonly used in Japanese cooking. Unlike true ginger, Japanese ginger's greenish-yellow rhizomes and roots are not considered edible. However, the plant's young buds and shoots are often harvested and used as an herb or garnish.
Japanese ginger grows in shady areas, often around ponds. In ideal growing conditions, outdoor plants form clumps around 18 inches tall. Potted plants with good fertilization can grow even larger, with some specimens reaching 3 feet. Japanese ginger needs moist soil that drains well to avoid winter root rot.
Cultivation for Eating
Both young shoots and buds are edible. If grown in soil, the buds are past their prime by the time they poke above the soil. In most cases, Japanese ginger grown for eating is grown under 4 to 6 inches of sawdust mulch. By growing under sawdust, it is easier to check for and harvest the tender flower buds of the Japanese ginger. The rhizomes and roots of the Japanese ginger are not edible.
Bud & Shoot Preparation
In many cases, the shoots are shredded and used as a garnish. The shoots are preserved in vinegar before being shredded and used in dishes such as miso soup. The buds are often prepared in the same way. Sometimes the buds are pickled for use later in the season.
The Japanese ginger plant is also used decoratively. If you allow your Japanese ginger to flower, the edible portions will be long past their prime. If allowed to flower, the Japanese ginger produces yellow flowers near the ground. The plant usually flowers in late summer. Because they are close to the ground and protected from above, the Japanese ginger relies on ground-based insects for pollination.
Japanese ginger is hardy in USDA zones 7 through 10. It requires soil that drains well, but also requires soil that is constantly moist. This particular plant will not do well in full sun, and requires partial shade or, preferably, full shade. It has a tendency to go dormant during hot, dry summers.