When can I plant zucchini in temperate Australia?

Sow direct from September to January, though outdoor sowings are safest after the last frost in mid-October. A second sowing in January gives a fresh plant that crops through autumn.

How long does zucchini take to grow?

It is one of the fastest summer crops — germination in 6–12 days and picking from as early as 50 days after sowing. Once fruiting starts, plants need harvesting every day or two.

Why are my baby zucchini rotting and falling off?

Fruit that yellows and rots from the tip has not been properly pollinated, which is common early in the season and in wet weather. Hand pollinate female flowers with a male flower in the morning and the problem usually stops.

How many zucchini plants do I need?

For most households, one or two plants are plenty — a healthy plant produces several fruit a week at peak. Space plants 50–80 cm apart so air circulates and mildew is slower to take hold.

When to plant Zucchini in Temperate Australia

Sow zucchini in temperate Australia from September to January. Method: sow direct. Seeds germinate in 6-12 days, with harvest roughly 50-100 days after sowing.

Temperate zone — applies to Sydney, Melbourne, Adelaide, Perth, Newcastle and similar areas. Growing elsewhere? Cool · Subtropical · Tropical · Arid.

Zucchini is sown direct from September to January in temperate Australia, 15–20 mm deep into warm soil. Everything about it is fast: seedlings appear in 6–12 days, first fruit can come from around 50 days, and one or two plants will feed a household through summer. Give each plant real room — 50–80 cm apart with 80–120 cm between rows — plus full sun, rich soil and consistent water. The realistic expectation is a glut, so sow fewer plants than you think you need and pick fruit small, when it is at its best.

Sowing calendar — temperate zone

Green months are your sowing window: September to January.

Growing notes

Like all cucurbits, zucchini is frost tender, and the temperate window reflects it. September sowings only succeed under cover or in a genuinely warm spot, because the last frost normally arrives around mid-October; direct sowing from mid-October onward is the low-stress path. The January end of the window is one of zucchini's quiet advantages — with only 50–100 days to maturity, a midsummer sowing still crops well through autumn before the May frosts, and a fresh young plant often out-produces a tired spring one that mildew has caught up with.

Sow two seeds per station and thin to the strongest. The soil should be rich — a bucket of compost dug in per plant is not excessive — and watering should be deep and regular, at the base, keeping the foliage dry to slow powdery mildew.

The near-universal failure is small fruit yellowing and rotting from the flower end, which is a pollination problem rather than a disease. Bees do the job when flowers of both sexes are open together, but early in the season or in wet weather it pays to hand pollinate: pick a male flower (plain stem), strip the petals, and dab pollen into female flowers (small zucchini behind the bloom) in the morning. Harvest every day or two at 15–20 cm; fruit left a week becomes a marrow and slows the plant down.

Zucchini at a glance

Sowing depth	15-20 mm
Plant spacing	50-80 cm
Row spacing	80-120 cm
Germination	6-12 days
Days to maturity	50-100 days
Frost tolerance	Frost Tender
Method	Sow Direct

Companion planting

Grows well with

Nasturtiums Marigold Nasturtiums Sweet Corn

Nasturtiums: Deters aphids and squash bugs

Marigold: Deters nematodes; attracts pollinators for better fruit set

Nasturtiums: Deters squash bugs and aphids

Common questions

When can I plant zucchini in temperate Australia?: Sow direct from September to January, though outdoor sowings are safest after the last frost in mid-October. A second sowing in January gives a fresh plant that crops through autumn.
How long does zucchini take to grow?: It is one of the fastest summer crops — germination in 6–12 days and picking from as early as 50 days after sowing. Once fruiting starts, plants need harvesting every day or two.
Why are my baby zucchini rotting and falling off?: Fruit that yellows and rots from the tip has not been properly pollinated, which is common early in the season and in wet weather. Hand pollinate female flowers with a male flower in the morning and the problem usually stops.
How many zucchini plants do I need?: For most households, one or two plants are plenty — a healthy plant produces several fruit a week at peak. Space plants 50–80 cm apart so air circulates and mildew is slower to take hold.

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