What is it?
This vine from Asia first established in the wild in New Zealand as early as 1926. Most of us will know it by its pretty flowers and lovely fragrance, but when it spreads into the wrong places it wrecks havoc and has been likened to old man’s beard (Clematis vitalba) for the devastation it can cause. Japanese honeysuckle is now banned from sale, distribution and propagation in New Zealand.
Where is it found?
Japanese honeysuckle is mainly found on the edges of bush remnants, wasteland, roadsides, and around old sheds and hedgerows on established farms and lifestyle blocks. As it was once a garden favourite, it is often found around old homesteads.
Why is it wicked?
Japanese honeysuckle will climb over and smother anything in its path, and can even cause the collapse of the forest canopy. It can grow 15 m in a year and is mostly a problem in small patches of bush, and around the edges of forest. For example, on the East Coast, 890 kg of mostly Japanese honeysuckle was removed from a tiny reserve (less than 2ha). The seeds of Japanese honeysuckle are easily spread by birds, and possibly even possums, but mostly it spreads by stems dumped in garden waste.
What can you do?
For small sites the best approach is to clear stems by hand and dig out any roots. For larger infestations using herbicide will be most effective. The best technique is to cut the stump close to ground level and paint or brush herbicide on immediately – check out the weed search at http://www.weedbusters.org.nz/weed_info/detail.asp?WeedID=101 for control methods. Take care disposing of the stems and roots. Vines should be buried, burned or placed in a black plastic bag and left to rot in the sun.
The native clematis (Clematis paniculata) is lovely with masses of snowy white flowers. You could also try native jasmine (Parsonsia heterophylla). Star jasmine (Trachelospermum jasminoides) is another attractive plant with white star-like flowers and glossy leaves.
Weedbusters is an interagency weeds awareness programme supported by all regional councils and unitary authorities, the Department of Conservation, Biosecurity New Zealand, Federated Farmers, Biodiversity New Zealand, NZ Landcare Trust, Nursery and Garden Industry Association, NZ Biosecurity Institute, and NZ Plant Protection Society.