New Zealand Treecrops Association

Information Exchange Mailroom

Information Request:

Is anyone having success growing walnuts in Northland? We are planning to plant Meyric on Nigra rootstock, does that sound like a good choice for an area with less winter chill?

Janine Williams
Hukerenui, Whangarei

Replies Received:

There are 3 main problems with growing walnuts in Northland, in order of seriousness;

1. Heavy clay soils. Walnuts need a free draining soil. So with the other problems in growing walnuts in Northland, this pretty well rules out growing walnuts in this region if you have a heavy clay soil. Your idea of using Juglans nigra rootstocks would help, and if you are just wanting to plant a handful of trees for home use then it would be worth a try.

2. Wet summers. Walnuts are semi desert plants, and ideally want no rain at all between September and April, certainly not during the day! Now of course this doesn't happen, but every hour of rainfall during the hours of daylight increases the amount of blight damage. The most susceptible varieties to blight are the Californian varieties, except Serr. Of the New Zealand selections, Meyric seems to suffer the most. Rex is relatively tolerant, but seem to require a fair amount of winter chilling, but this may not be problem most years in Northland. We have selected a variety which is showing low blight damage and has low requirements to winter chilling, called Roadside 12.

3.Winter chilling. The importance of this will depend a bit on the local microclimate. Walnuts do require winter chilling for fruit bud set, more for some varieties than others. Of course, seasons vary considerably, so this may be alright one year, and not the next.

Overall, if you can satisfy the free draining soil requirement, you could grow walnuts successfully in Northland, provided you were not dependant on a bumper crop of nuts every year. The best way to go about it would be to find a tree already growing up there, that is cropping well, and has reasonable quality nuts, and grow seedlings from that. If you planted them 4 metres apart as a nutting forest, you would have a successful project. Your main product then would be timber, the most valuable wood in the world, and the nuts would be a bi-product.

Nick Nelson Parker

http://www.treecrops.org.nz/knowl/infothr/walnut2.html
Created: 2003 July 4 - Updated: 2003 July 8 - Updated: 2007 August 11