Plant garlic in autumn, into early winter. For most of New Zealand that means April to May. Gardens in the far north go earlier, in March to April, and the coldest inland areas go later, in May to June, close to the winter solstice. Whichever window you're in, expect to dig the bulbs roughly seven months later, between October and January.

The old NZ rule is to plant on the shortest day and harvest on the longest. That fits the coldest areas, where June planting leads to a December harvest. For most of the country it's late: the window there closes at the end of May.

Quick Answer: Garlic Planting Times by Region

Where you garden Zone Plant cloves Harvest
Northland, Auckland and coastal Taranaki Sub-tropical March–April October–November
Most of the country Temperate April–May November–December
Central Otago, Queenstown, the Central Plateau and Canterbury Cool/mountain May–June December–January

Where these months come from. Koanga Institute, which grows and sells NZ seed garlic, gives April to May for its garlic lines. That's the baseline. The earlier and later windows for the far north and the cold inland south are Garden Bureau's own adjustment for each zone's frost season, not a separate published source. If your garden sits near a boundary, use your own frost dates to decide which way to lean. The NZ frost dates guide lists them by region.

Why Planting Time Matters

Garlic is frost-hardy, so cold weather after planting isn't the risk. Timing matters because of what the cold does. As general horticulture: garlic needs a spell of cool weather (below about 10°C) to trigger clove formation, and hardneck types need more of it than softnecks. Without enough, a clove grows into a single round bulb instead of splitting into a head of cloves.

As a general rule (not zone-specific data):

  • Too early, and cloves can sit in cold, wet soil for longer than they need to, which raises the risk of rot.
  • Too late, and the plant gets less cold and less growing time before spring warmth arrives. Expect smaller bulbs, and rounds instead of split heads.

Northland, Auckland and Coastal Taranaki: March–April

The far north plants earliest, in March and April, and harvests in October and November. Frost risk here runs only from May to September.

The early start is about the mild winter. There's less cold to gain by waiting, so planting earlier gets the crop growing sooner. An early autumn start also reduces rust risk. For the signs of rust, and how to tell it from white rot, see Rust and White Rot in NZ Garlic.

Mild winters can also leave garlic short of the cold it needs to split into cloves. If last year's crop came up as single rounds, read Why Is My Garlic Not Forming Bulbs in NZ Sub-Tropical? before you plant.

Elephant garlic, which Koanga lists as from Northland, is worth knowing about here. Botanically it's a leek relative rather than true garlic. As a general rule, it needs less winter cold than true garlic to form its large cloves.

Most of the Country: April–May

For the bulk of the country, plant in April and May and harvest in November and December. This is the same window Koanga gives, with frost risk from April through to November.

Cloves planted in April or May get the cold they need over winter. They're also in the ground early enough to put on leaf before spring warmth arrives.

If your garlic has come up small or unsplit in past years, Why Is My Garlic Not Forming Bulbs in NZ Temperate? works through the usual causes, and Why Is My Garlic Bolting Early? covers plants that run to flower. Variety picks for this window are in Best Garlic Varieties for NZ Temperate Gardeners.

Central Otago, Queenstown, the Central Plateau and Canterbury: May–June

The coldest gardens plant latest, in May and June, near the June solstice, and harvest in December and January. Frost season here runs from March right through to November.

Here the long, cold winter gives garlic plenty of chilling whether cloves go in during May or June, so there's no need to rush in April while soils are still settling into winter. The one limit is the ground itself: in the coldest spots, plant before it freezes too hard to work. The later harvest follows from the later start, about seven months on.

Canterbury. Plant through May and into June, once autumn's warmth has properly gone. As general advice for the high country (the Mackenzie Basin, Hanmer and around Arthur's Pass), aim for the May end of the window. Those areas can freeze too hard to dig by June, so get cloves in while the ground is still workable rather than holding out for the shortest day.

For variety choice in cold gardens, see Best Garlic Varieties for NZ Cool/Mountain Gardeners. If you've had problems, see Why Is My Garlic Not Forming Bulbs in NZ Cool/Mountain?.

Choosing Seed Garlic

Koanga Institute sells four named garlic lines:

  • Rocombole Early Red, Rocombole Early White and Rocombole Ruby Red. Koanga lists these with a Southland origin and gives 10–12.5cm diagonal spacing, planted April to May.
  • Elephant, listed as from Northland. Koanga recommends removing its flower heads while they're young, before they open, to encourage larger cloves. The flower heads are edible too.

Buy garlic sold for planting rather than bulbs from the kitchen, so you know what variety you're growing.

How to Plant Garlic

  1. Pick the spot. Koanga's growing notes call for light, well-drained soil in a sunny position. Dig in compost before planting.
  2. Split the bulb on planting day and use the largest cloves. As a general rule, bigger cloves give bigger bulbs.
  3. Plant each clove 5cm deep and 15cm apart, pointed end up. (Koanga's Rocombole lines can go a little closer, on 10–12.5cm diagonal spacing.)
  4. Mulch after planting to keep weeds down over winter.

Shoots usually appear within a few weeks. The tops handle winter frost: garlic is a hardy crop.

When to Harvest

Garlic takes about seven months from planting, so your harvest month follows your planting month: October–November in the far north, November–December for most of the country, and December–January in the coldest areas.

Koanga's harvest notes for Elephant garlic, which follow common practice for garlic generally:

  • Stop watering once the tops start turning brown.
  • Lift the bulbs once the leaves have browned but before they've completely died back. Left too long, bulbs can begin to split.
  • Dig them out with a fork rather than pulling them.
  • Cure them under cover, out of the rain and direct sun, with plenty of airflow, and keep the tops attached while they cure and in storage.

Know your zone? See the full planting calendar for the sub-tropical north, most of the country or the cool/mountain south and inland.