Wild or kahili ginger is making its presence known around Waiatarua at the present time in the form of bright orange seedheads. Ginger does most harm because its rhi zomes form plate-like infestations on the forest floor which prevent native plants es tablishing. As it is shallow rooted, it also contributes to land slipping in heavy rains as we have seen with Cyclone Gabrielle. On the other hand it is not the hardest pest plant to control. Seeds last for up to six years so ongoing attention to a site can result in its elimination. Seeds set most on plants on forest margins. In the darkness of the forest they don’t.
Having tackled a few infestations over the years, here’s a few tips for getting rid of it with the least effort. At this time of the year cut off the seed heads and put in a big plastic rubbish bag and when the public weed bin is at the hall, tip them into that. That at least stops a new round of seeds being spread by birds (or, it is thought, possums).
To adopt a more permanent plan, cut the leaf and flower stalks off at the base (above the pink collar at the base) and paint the cut stump with either liquid or paste. The chemical to use is metsulfuron methyl at 1 gram granules per litre of water for painting or Met-Gel, a made-up product obtainable online or at some retailers (see below).
The mix with water is cheaper and I have put some in a tall jam jar and painted it on with a paint brush. That’s a good approach if your site is relatively easy to get around. If you have steep land and you’re climbing/crawling around, gel is better.
You just leave what you cut on the ground to rot down. Over time the rhizome plate will shrink and disappear. So there’s nothing to take to a bin. You have to be careful not to get paint or gel on natives and you are advised not to plant into the area for six months.
I find these methods better than spraying the whole plant as the spray might affect surrounding natives.
The best place to get Met-Gel is the cut-n-paste website online – they also have a list of stores where it is available, including Kings Plant Barn and Placemakers, see: https:// www.cutnpaste.co.nz
This website sells the granules in a range of quantities https://www.rainbowbrown.co.nz/