Many of the nurseries around the country will ship nationwide. There are, however, also pleanty of good local nurseries worth looking into.
Sutherland Nursery
sutherlandnursery.co.nz
Listed here are some of those who advertise nationally.
Southern Woods
www.southernwoods.co.nz
Te Kahuri Nurseries
www.tekahurinurseries.co.nz
Edible Garden
www.ediblegarden.co.nz