Pest Ginger in New Zealand

Biological Control (weed): Kahili Ginger

Wild ginger is fragrant, leafy, rhizomatous, semi-tropical perennial herb which can grow up to two meters tall. It has a magnificent display of large conspicuous yellow flowers in late summer, followed by scarlet seeds in capsules.

In the early 1890s Kahili ginger (Hedychium gardnerianum) was introduced to New Zealand as an ornamental plant. Kahili ginger is a native of India and the lower slopes of the Himalayas in Nepal. It produces massive branching rhizomes which spread and intertwine to create a bed of about a meter deep. Where wild ginger exists in abundance very little else will grow. The dense root system prevents regeneration of other plants while above ground ginger blocks the light and smothers other species. The major problem areas are Auckland, Wellington and Northland. In these areas (and some other less requiring areas) the ginger is subject to Pest Plant Management Strategies.

Currently kahili ginger is invading, and d...