August is the biggest sowing month of the year here by volume — 20 windows open at once — but the sharpest contrast isn't the size of the list, it's the timing of what's already underway. While temperate gardeners are only just starting tomato seed indoors this month, this zone's tomato, capsicum and eggplant were sown back in June and are already transplantable now.

Quick Answer: What to Sow Now

Twenty crops are open for sowing this August: basil, beetroot, broad beans, broccoli, capsicum, coriander, cucumber, eggplant, kale, lemon, mandarin, mizuna, onion, orange, pak choy, radish, shallot, silverbeet, tomato and turnip.

Already Ahead: Tomato, Capsicum and Eggplant

All three move into their August–October transplant window this month, having spent June and July as trays — a full two months ahead of the temperate zone, where tomato's indoor sowing only starts now. Cucumber joins the trays-only start this month too (sowing August–November, transplanting September–December), on the same earlier-by-two-months pattern.

The Big Spring Batch

Broccoli and kale both open for the first time all year. Broccoli (August–November) needs raising in trays and transplanting at 4–6 weeks, netted against white butterfly from day one. Kale (August–October) can be direct sown or raised in trays and is hardy enough that cold weather improves it rather than threatening it.

A run of direct-sow staples opens alongside them:

  • Beetroot and silverbeet — both sow August through May, among the widest windows on this list.
  • Broad beans — August through October, direct sown, tops pinched at flowering to deter aphids.
  • Pak choy and radish — August through May and August through April respectively, both fast and forgiving.
  • Mizuna — August through December, a quick cut-and-come-again green.
  • Turnip — a narrower August–October window; it dislikes summer heat, so this is genuinely its season.
  • Shallot — the tightest window of the month, August–September only, planted as bulbs 5cm deep and 15cm apart.

Still Going: Basil, Coriander and Onion

All three opened last month and remain sowable — basil through December, coriander through November, onion through September.

Citrus, Still an Option

Lemon, mandarin and orange remain inside their April–September window. Best Lemon, Best Mandarin and Best Orange Varieties cover cultivar choice.

Also Harvestable This Month

Jerusalem artichoke's harvest window closes at the end of August — dig what's left rather than letting it run on. Carrot, lime and tamarillo are all still cropping too.

Timing Notes for Sub-Tropical Gardens

August still sits inside this zone's May–September frost window, which is exactly why the trays-only crops above haven't gone outside yet despite being weeks ahead of temperate equivalents. The volume of sowing windows opening at once here mirrors the rest of the country's own August rush — this zone isn't exempt from a big spring sowing month, it just runs its tender crops on an earlier clock within it.

With this many windows opening simultaneously, tray and indoor space are likely to be the real bottleneck this month rather than anything about soil temperature or daylight. Prioritise broccoli and kale for tray space early, since both need weeks of growth before transplanting, and keep the direct-sow staples — beetroot, silverbeet, pak choy, radish — for whenever a bed actually frees up, since none of them are in any particular rush relative to each other.

Recommended Cultivars

  • Basil — Cinnamon (Kings Seeds NZ), Genovese (Koanga Institute)
  • Beetroot — Bull's Blood (Kings Seeds NZ, Koanga Institute)
  • Broad Beans — Coles Prolific (Kings Seeds NZ), Red Seeded (Koanga Institute)
  • Broccoli — Belstar F1 (Kings Seeds NZ), de Cicco (Koanga Institute)
  • Coriander — NZH (Koanga Institute), Picante (Kings Seeds NZ)
  • Cucumber — Amira F1, Crunchy F1 (both Kings Seeds NZ)
  • Kale — Blue Ridge F1 (Kings Seeds NZ), Borecole (Koanga Institute)
  • Silverbeet — Bright Yellow, Ford Hook Giant (both Kings Seeds NZ)
  • Tomato — Albenga Oxheart (Kings Seeds NZ), Alma (Koanga Institute)

Capsicum, eggplant, lemon, mandarin, mizuna, onion, orange, pak choy, radish, shallot and turnip don't have an approved cultivar pick sourced for this zone yet.

Know your zone? Explore the full NZ Sub-Tropical Planting Calendar for month-by-month sowing and harvest timing.