When to plant Squash in Cool Australia

Cool zone — applies to Hobart, Canberra, Ballarat, Orange, Armidale and similar areas. Growing elsewhere? Temperate · Subtropical · Tropical · Arid.

Sow squash direct from October to December once frost has passed and the soil has warmed, with a final January sowing possible for a late crop in milder cool districts. Set the large seed 15-25 mm deep, ideally on a slight mound to keep it from rotting, and expect germination in 6-18 days depending on soil warmth. Squash is fast once away, maturing in 50-90 days. Give plants plenty of room at 60-100 cm apart with 90-100 cm between rows. Being frost tender, squash needs the short warm window of Hobart, Canberra and Ballarat used well, so do not rush it into cold ground.

Sowing calendar — cool zone

Green months are your sowing window: October to January.

Growing notes

Squash is a warmth-lover in a cool climate, so the season is short and every decision should protect that warmth. The single biggest failure mode is sowing too early: seed dropped into cold, wet soil in early spring simply rots rather than germinating. The fix is discipline, waiting until frost has genuinely passed and the soil is warm to the touch, or starting seed in pots under cover a couple of weeks ahead and transplanting carefully once nights are mild.

Squash are hungry and thirsty. Plant into ground enriched with plenty of compost or well-rotted manure, and keep the water up steadily, especially once fruit sets, watering at the base to keep the leaves dry.

That dryness matters because powdery mildew is the second great failure mode, coating the leaves white in the humid, still conditions of a cool-zone autumn as the season closes. Space plants at the full 60-100 cm for airflow, water in the morning, and remove badly affected leaves. Plant nasturtiums nearby, which help deter squash bugs and act as a trap crop for aphids. If bees are scarce and fruit is dropping while tiny, hand-pollinate by transferring pollen from a male flower to a female one in the morning, a common need in districts like Orange and Armidale early in the season.

Squash at a glance

Companion planting

Grows well with

Nasturtiums: Deters squash bugs; trap crop for aphids

Common questions

When can you plant squash in cool climates?

Wait until frost has passed and the soil has warmed, which means October to December in cool cities like Canberra and Ballarat, with a January sowing possible for a late crop. Squash is frost tender, so sowing too early into cold soil causes the seed to rot.

Why is my squash seed not germinating?

Cold, wet soil is almost always the cause, as squash needs warmth to sprout. Delay sowing until the soil is warm to the touch, or start seed in pots under cover and transplant once nights are mild. In warm soil it germinates in 6-18 days.

How do you stop powdery mildew on squash?

Space plants the full 60-100 cm apart for airflow, water at the base in the morning to keep leaves dry, and remove badly affected foliage. Mildew thrives in the still, humid conditions of a cool-zone autumn, so good airflow is your best defence.

Why are my squash fruit falling off while small?

This is usually poor pollination, common when bees are scarce early in the season. Hand-pollinate by transferring pollen from a male flower to a female one, the female being the one with a tiny fruit behind the bloom, ideally in the morning.

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