The New Zealand Plant Conservation Network

We have numerous Piper excelsum (Macropiper excelsum, kawakawa) plants growing on our property. Late last year I noticed several plants were showing wilting of the leaves and stem. The onset is very rapid, with leaves wilting and dying within a few days after symptoms first appear. The problem seems to be limited to individual stems on a plant - if they are removed it seems the rest of the plant will generally survive. Usually individual stems are affected, while other stems on the same plant continue to show their normal vigour.
I have cut out and destroyed affected material, but the problem is persisting. We would be very upset to lose this species from our property and would greatly appreciate any comments on the cause and possible treatments for the problem.

I see that you haven't had a reply to this one, and as a complete non-expert I can't suggest any causes - but I can say that we had a similar problem at our place in Auckland some four years ago. We lost almost all of our big kawakawa plants - generally the whole thing rather than just individual stems. However, now we seem to have more plants than ever (well into three figures), and they come up very easily through natural dispersal (mainly from blackbirds, I think!). So if it gets any worse, you may just have to wait and trust to nature - it worked in our case.

Thanks very much for your comments - I'm pleased that there is hope for the kawakawa in our Auckland garden. With its handsome foliage, the fact that it thrives in shady situations, and is a great food source for kereru and other birds, I consider that kawakawa is a highly under-rated plant for the garden.

Glad you seem to have had kereru eating the fruit - we've never had the pleasure of seeing that!

Almost every day in summer we are fortunate to have kereru visit our garden to feed on the kawakawa fruit, often more than one bird at a time. It's one of the reasons we are so concerned about the possibility of losing the plants from our garden.