New Zealand spinach needs a very long season to produce ripe seed. A very early sowing in a greenhouse and later setting out with 60-70 cm between may succeed if the autumn is long, sunny and mild. The fully ripe, dark-brown seeds easily tumble, so some kind of cloth beneath the winding plants is necessary to prevent the seeds from falling to the ground. Some unripe seeds might remain on the stalks. Allow them to ripen indoors and strip them off when fully ripe. The big angular seeds are easy to clean by sieving and winnowing.