Winter isn't a dead season in a New Zealand vegetable garden, but the list of things worth planting is shorter and more region-dependent than in spring or summer.
Garlic is the classic winter planting job. By tradition it goes in on the shortest day, around 21 June. In the North Island, plant from April through to June. Further south, Canterbury gardeners should plant from April to May, while in Otago cloves can go in a little earlier, from March to May. Garlic needs a genuine cold spell to bulb up well, regardless of region.
By tradition it goes in on the shortest day, around 21 June.
Broad beans are another good winter-adjacent crop: sow them March to April in Canterbury and Otago, March to May in Waikato and Wellington, and March through to June in Auckland and Bay of Plenty. As a nitrogen-fixing legume, they also improve the soil ahead of spring plantings.
Rhubarb is a genuine winter job: plant dormant crowns in June or July, everywhere in the country. Auckland, Bay of Plenty, Waikato and Wellington gardeners can extend that into August too. Resist harvesting in the first year while the plant establishes. Onions can also go in during August nationwide, with Auckland and Bay of Plenty gardeners able to start as early as March.
For brassicas, the picture varies more by region. In Auckland and the Bay of Plenty, broccoli, cauliflower and cabbage can all be sown right through winter into July and August. In Waikato and Wellington the window narrows to July-August. In Canterbury and Otago, hold off on sowing new brassicas until August: winter itself is generally too cold there to start them from seed outdoors. Kale is a useful crop to know about here too. It's actually sown from summer through autumn (January to May, depending on region) rather than in winter. But because it's frost-hardy, it's one of the few vegetables still giving you pickings right through the cold months once established.
Spinach can keep going through winter in the north. Auckland, Bay of Plenty, Waikato and Wellington gardeners can sow right through June, July and August, but in Canterbury and Otago it's best to wait until August. First-early potatoes can go in from August in Auckland, Bay of Plenty, Waikato and Wellington. Leeks can be started from August too, but only in Auckland and the Bay of Plenty. Elsewhere, both wait for spring.