Wild ginger

Wild ginger is a native of India. It was introduced into New Zealand as a decorative plant, which has now escaped from gardens. Wild ginger grows from large, branching rhizomes and produces vertical stems annually. The beds of living rhizomes can form a dense layer up to one metre thick. Adult stems produce large wax-covered ovate leaves.

Kahili ginger (Hedychium gardnerianum) produces seed and is therefore more common in the Wellington region. Kahili ginger has yellow flowers with distinct red or orange stamens. The stem can reach up to two metres.

Yellow ginger (Hedychium flavescens) does not produce seed. The flowers are a light-cream colour and are generally smaller that kahili ginger. Yellow ginger can grow to five metres and produces massive rhizomes. It is spread through moving plant material

Wild ginger is a spreading groundcover, colonising indigenous bush, gardens and reserves. It spreads rapidly and has the ability to cause significant change to ecosystem structures including tall and undisturbed forest, riverbanks and open areas.

The long-term objective is to suppress the density of wild ginger to minimise its impact in the Wellington region.

Wild ginger is currently established throughout the Wellington region. With its ability to cause serious adverse impacts to forests and other types of communities it is important to ensure this species is controlled.

Landowners, occupiers or their agents are required to destroy all sites of wild ginger on their land on an annual basis. Plants should be destroyed prior to seeding and by approved methods. Please contact Greater Wellington, Pest Plant Department if there are any infestations in your area.

It is illegal to sell, propagate, or distribute any parts of wild ginger in the Greater Wellington region.

1. Dig it out - use a garden fork to loosen up the earth surrounding the plant. Pull the plant free from the loosened earth. If the plant is large, it may need to be cut up with a spade for ease of removal. The leaf stems can be composted but the rhizomes and any flower or seed heads must be disposed of at a registered landfill or dried and burnt. Check for seedlings in summer.

2. Cut and spray - clear litter, covering soil and vegetation from around the clumps of wild ginger so that the spray will get a good contact with the rhizomes. Cut the stem above the rhizomes. Spray the clumps completely with Escort at 1gm/L water. Replace the stem over the rhizomes. Please read the manufacturer's label. Follow up will be needed to control seedlings.

3. Bore and fill - expose all of the rhizomes. Make up Escort at 2gm/L water. Bore out holes in every second or third rhizome with a battery drill (11-13 bit) or knife. It is important to get the last rhizome in each string. Immediately fill each hole with the chemical solution. Please read the manufacturer's label. Follow up will be needed to control seedling.

4. Hire a contractor to treat it - we can put you in touch with one.

For more information or advice about pest plants, contact Greater Wellington's Biosecurity staff on 06 378 2484 or 04 526 5325 or email pest.plants@gw.govt.nz.