Frost isn't the constraint in a Wellington March — Wellington's own frost data shows coastal suburbs running effectively frost-free and even the colder inland valleys not seeing their first frost until May. What actually shapes the March garden here is wind: the same nor'westers and southerlies that make tomatoes hard work in this city start picking up in earnest as summer turns, right when a lot of March's jobs involve young seedlings and top-heavy, still-cropping plants.

The Wellington March Growing Context

Wellington sits in New Zealand's nz-temperate zone — the same zone as Christchurch, Nelson, and Palmerston North data-wise — but the local experience of March here is dominated by exposure, not by any special frost or heat pattern. A few things worth knowing before you sow:

  • Soil is still warm from summer, so germination is quick if you can keep seedlings from drying out or getting battered.
  • Days are shortening and nights are cooler, which suits several autumn crops better than a midsummer sowing would.
  • Frost genuinely isn't a factor yet anywhere in the city — the zone's frost-risk period doesn't open until April, and Wellington's coastal suburbs barely see it even then.
  • Wind exposure varies hugely block to block. A courtyard on the lee side of a house can be a full climate zone milder, in practical terms, than an open bed 50 metres away.

If you garden in one of the colder inland valleys — Johnsonville, Ngaio, Karori — treat the frost-dates guide's May 1 first-frost estimate as a planning marker for autumn crops that mature slowly. If you're coastal, that date barely applies to you; wind is still the thing to plan for either way.

What to Sow Now

Beetroot, carrot and silverbeet all have wide autumn sowing windows here (Beetroot and Silverbeet run August–May, Carrot September–May), so March sowings are safely inside the window rather than a late scramble. Direct sow all three — none transplant well — and in an exposed Wellington bed, cover the row with shade cloth or a light frost cloth for the first 10–14 days purely as wind protection while the seedlings establish; it comes off once they've got true leaves.

Lettuce is different: its sowing window closes at the end of March, so this is the last succession sowing before the gap until spring. Raise it in trays in a sheltered spot rather than direct-sowing into an open bed — a March nor'wester can shred lettuce seedlings before they've got a root system to anchor them.

Pak choy and radish both still have open windows this month (Pak Choy August–May, Radish August–April) and are two of the easiest wins for a wind-exposed Wellington section — both are fast, both tolerate a rougher start than lettuce, and radish in particular is done in weeks, so a bad week of weather doesn't cost you much.

Hold off on broccoli, kale and garlic — their windows open later (broccoli and kale in August, garlic in April), and an early Wellington sowing just means a seedling exposed to the season's worst wind before it's established enough to handle it.

What to Harvest and Watch This Month

Tomatoes, courgettes, cucumbers, climbing beans and peas are all still cropping, and March is also when pumpkin and yacon harvest windows open. The wind angle matters here too: this is the month a lot of Wellington gardeners lose a barely-staked tomato plant to a single bad afternoon, right as it's finally carrying real fruit. Walk your stakes and ties before, not after, the next forecast nor'wester — a wire cage or a second tie point is a five-minute job that prevents losing weeks of fruiting.

Beetroot, carrot, silverbeet and spinach are all within their long harvest windows and don't need anything wind-specific — pull or pick as needed.

Garden Jobs for a Wellington March

Secure everything top-heavy before autumn storms properly set in. Tomatoes, climbing beans and peas on flimsy single stakes are the most common March casualty in this city — not frost, not pests, wind.

Clear finished summer crops as they tail off rather than leaving half-productive courgette or cucumber plants taking up a sheltered spot an autumn sowing could use instead.

Start scouting your April garlic bed now. Garlic's sowing window opens next month, and in a wind-exposed section it's worth choosing the spot for shelter as much as for sun — a sheltered bed also holds soil moisture better through Wellington's drying nor'westers.

The Wellington-Specific Mistake

The most common one isn't a timing mistake at all — it's treating a Wellington section like a single climate. The coastal-vs-valley frost split is real (see the frost dates guide), but the wind split matters even more and changes street to street, sometimes fence to fence. A sheltered north-facing corner and an open bed 10 metres from it can run genuinely different growing seasons. Sow and stake for the spot you actually have, not the average for the suburb.

Ready for the full picture? See the NZ Temperate Planting Calendar → for every crop's sow, transplant and harvest windows.