Short answer: October brings just one genuinely new sowing window to cool/mountain gardens — cucumber — while tomato reaches the stage it's been waiting all year for and moves outside as a transplant. Five spring crops (broad beans, brussels sprouts, kale, mustard greens and turnip) close their sowing windows before the month is out.

The cool/mountain October context

The zone's frost period runs to the end of November — the same as temperate — so October is not frost-free, but the risk is easing enough that tomato's transplant window opens for the first time this year. What sets a cool/mountain October apart is the other end of the season: autumn frost returns as early as March here, a month earlier than in milder zones. That's not a footnote. It's why the same warm-season crops carry shorter harvest windows in this zone — sourced tomato harvest runs December–March rather than December–April, and basil January–March rather than January–April. Every seedling you plant out in October is aiming at a season that closes sooner, so getting it out on time matters more, not less.

Two practical caveats carry over from spring:

  • Soil warms slowly, so direct-sown seed is slow to show — a cucumber or carrot row can sit a fortnight before germinating.
  • "Cool/mountain" spans mild inland districts through to high-country gardens still catching hard October frosts. The windows below are broad national planting dates; match them to your own frosts and altitude, not the calendar.

What to sow now

Cucumber — the only new window

Cucumber's sowing window opens in October and runs through January, the single new sowing this month. It's frost-tender, so start seed in trays rather than in the ground — about a month before your last frost — and plant out only once frost risk has genuinely passed. Expect 60–80 days from transplant to harvest, which in this zone means an October sowing is aiming at a late-summer crop.

Cultivar picks: Amira F1 or Crunchy F1 (both Kings Seeds NZ), both raised as transplants.

Last call: five crops closing this month

All five have been open since late winter or early spring and shut at the end of October — in now, or wait until next year:

  • Broad Beans (open since August) — direct sow; harvest December–February.
  • Brussels Sprouts (since September) — raise in trays, net against white butterfly; the frost this zone reliably delivers sweetens them.
  • Kale (since August) — very hardy, and improves after frost.
  • Mustard Greens (since September) — tray-raise and transplant, or direct sow for a quicker baby-leaf cut.
  • Turnip (since August) — a cool-season crop that turns woody in summer heat, so this really is its last sensible window until autumn.

Still open

Hardy and cool-season crops carry on from earlier months and remain sowable if you haven't started: beetroot, broccoli, carrot, lettuce, radish, silverbeet and spinach are all hardy and fine direct-sown into cold soil, while coriander, mizuna, pak choy and peas are cool-season — happy in cool weather, worth a cloche over young plants in the hardest-frost gardens. Basil's window is also still open, but as the one frost-tender herb here it stays under cover until the last frost passes. If earlier peas flowered but set nothing in the cold, Why Are My Peas Not Flowering in NZ Cool/Mountain? covers the causes.

Transplant now: tomato leads

Tomato is October's headline. Its transplant window opens this month and runs through December — the first time all year it's safe to move seedlings from trays into open ground. Plant out only after the last frost, not on one warm week: in a cool/mountain garden a late-November frost is entirely plausible, and it can undo months of tray-raising overnight. Given the shorter runway here, harden seedlings off properly first so they don't stall — a checked transplant wastes weeks this zone can't spare. If earlier tomatoes have struggled to colour up before the cold returns, Why Are My Tomatoes Not Ripening in NZ Cool/Mountain? covers the short-season causes.

Broccoli and kale (both raised earlier) continue transplanting this month, and brussels sprouts and mustard greens sown in September now move out too. Net the brassicas against white butterfly as they go in.

Harvest now

October is when several long harvest windows actually open in this zone:

  • Beetroot, Radish and Silverbeet all reach the start of their harvest windows this month — the first roots and leaves of the new season. Growing Silverbeet Year-Round in NZ covers keeping it productive.
  • Coriander — cropping from earlier sowings; pick before it bolts. A cool start is what holds it back, the fix in Why Is My Coriander Bolting Immediately in NZ Cool/Mountain?.
  • Mizuna and pak choy — cut-and-come-again greens; take outer leaves rather than pulling whole plants.
  • Turnip — pull roots as they size up, before any heat turns them woody.

Recommended cultivars

  • Cucumber: Amira F1 or Crunchy F1 (both Kings Seeds NZ), tray-raised.
  • Tomato: Albenga Oxheart (Kings Seeds NZ), transplanted; or Alma (Koanga Institute), tray-raised and pricked out before planting at 50cm.
  • Broad beans, brussels sprouts, kale, mustard greens, turnip and the still-open salad crops: no zone-specific cultivar notes are catalogued for October's crops yet — choose an NZ-suited variety from your usual supplier.

Know your zone? Explore the full NZ Cool/Mountain Planting Calendar for month-by-month sowing and harvest timing.