May is the last sowing month of autumn across New Zealand. Beetroot, carrot, pak choy and silverbeet all close their windows at the end of the month in every region. After that, the only vegetable sowings until July are garlic in the coldest gardens and early tray-raised summer crops in the far north. Garlic is the crop where region matters most. Most of the country is planting its last cloves this month, while Central Otago and the high country are only just starting. Frost also reaches the far north this month, the last part of the country to get it.

Quick Answer: Plant These Anywhere in NZ

Seven crops are inside their planting window in every NZ growing zone this May:

  • Beetroot (sow August–May) — last month
  • Carrot (sow September–May) — last month
  • Pak choy (sow August–May) — last month
  • Silverbeet (sow August–May) — last month
  • Lemon, mandarin and orange (plant April–September)

All four vegetables close at the end of May everywhere, and none reopens until August or September. Sow early in the month, while there's still some warmth in the soil to help germination. Beetroot, carrot and silverbeet are frost-hardy. Carrot germinates more slowly now, so keep the seedbed from drying out until the seedlings are through. Silverbeet is the crop that will still be feeding you in July — see Growing Silverbeet Year-Round in NZ.

Citrus trees can still go in, but timing matters more now. Wherever frost is already arriving, a young lemon, mandarin or orange tree planted in May has only a few weeks to settle its roots before the coldest stretch. The planting-window notes specifically warn against putting trees in over midwinter in frosty areas. So in most of the South Island and inland North Island, plant this month or wait until September. Choosing a variety? The lemon, mandarin and orange guides compare the options.

Mandarin harvest opens in May in every zone (May–September), so established trees should start colouring up.

Not sure which zone you're in? The NZ frost dates guide covers it by town.

Sub-Tropical: Northland, Auckland and Coastal Taranaki

The seven crops above are the whole May planting list here. Garlic closed at the end of April. May is the first month with any frost risk in this zone (May–September), months after the rest of the country. Established plants aren't suddenly at risk. The caution is for young plantings, especially citrus trees put in over the last month or two. Habits gardeners further south use all year, like checking the forecast before a cold night and keeping frost cloth handy, are worth setting up now.

May is also the end of the long sub-tropical summer harvest. Tomato, courgette, capsicum, eggplant, basil, passionfruit, lettuce and peas all reach the end of their harvest windows this month, so pick what's left.

What carries on is the autumn and winter harvest:

  • Jerusalem artichoke harvest opens (May–August). Cold weather improves tuber colour, and tubers can be left in the ground and dug as needed.
  • Tamarillo (to November), yacon (to July) and feijoa (to July) keep cropping. See the tamarillo growing guide and feijoa varieties.

Temperate: Most of the Country

Across most of the country, garlic's sowing window closes at the end of May (April–May). This is the last month to plant cloves for this season. Depth and spacing don't change for a late planting (5cm deep, 15cm apart), and the roughly seven-month run still lands in November–December. Miss May and the window doesn't reopen until next April.

Frost has been possible here since April, and the harvest list is shrinking:

  • Climbing beans, lettuce and peas all finish their harvest windows this month. Clear the last of them and free up the beds.
  • Pumpkin and radish run until June.
  • Feijoa (to July) and Jerusalem artichoke (to August) carry on.

Cool/Mountain: Central Otago, Queenstown and the Central Plateau

In cool/mountain gardens, garlic's sowing window opens this month (May–June) — the latest in the country. The planting-window notes give the reason: hardneck garlic needs an extended spell of cold below 10°C to trigger clove formation, and this zone supplies it reliably. Plant cloves 5cm deep and 15cm apart into compost-enriched ground for a December–January harvest. The Canterbury garlic guide goes into more detail, and Rust and White Rot in NZ Garlic covers the two diseases worth planting against.

The May–June window for this zone is our own guidance for the coldest gardens, not a single supplier's figure. Most NZ seed houses quote a broad autumn planting without splitting it by zone. The principle — colder gardens plant later — is well founded. Treat the exact month as a recommendation, and adjust it for your own altitude and frost pattern.

Frost has been part of the picture here since March, so the harvest is firmly at the tail of the season. Climbing beans, lettuce and peas finish this month. Pumpkin and radish run until June, and Jerusalem artichoke until August.

Recommended Cultivars

These cultivar picks for May's sowings come from NZ suppliers:

  • Garlic (temperate and cool/mountain) — Rocombole Early Red, Rocombole Ruby Red, Rocombole Early White (Koanga Institute)
  • Beetroot — Golden Detroit, Cylindra (Kings Seeds NZ); Detroit Red (Koanga Institute)
  • Carrot — Amsterdam Sprint, Touchon (Kings Seeds NZ); Akaroa Long Red (Koanga Institute)
  • Silverbeet — Ford Hook Giant, Bright Yellow, Ruby Red (Kings Seeds NZ)

Pak choy and the citrus trees don't have approved cultivar picks yet.

May Garden Jobs, Anywhere in NZ

These are general late-autumn jobs, not zone-sourced planting data:

  • Treat the end of May as a deadline. Sowing the last roots and greens "after one more warm week" is the easiest way to miss the window entirely.
  • Mulch beds as they empty instead of leaving soil bare to winter rain. It protects soil structure and keeps weeds down until spring.
  • Check new garlic after hard frosts. Frost doesn't harm established cloves, but newly planted ones can heave. Firm them back in.
  • Cure and store the last pumpkins in a dry, airy spot.

Next Steps

For month-by-month sowing and harvest timing in your area, see the full planting calendar for your zone: