How to grow Squash in Australia
Squash here means summer squash, especially the button or pattypan types with scalloped, flying-saucer-shaped fruit in yellow, green or white. They grow on compact bushes, crop heavily about six to eight weeks after sowing, and are best picked small and often, like zucchini.
📖 Our full guide: How to Grow Squash in Australia
At a glance
When to sow by region
| Region | When to sow | Regional note |
|---|---|---|
| South East Queensland | August to February | |
| Northern Rivers NSW | September to February | Sow from September to February. Starting in September protects young plants in hinterland frost pockets. |
| Sydney & Coastal NSW | September to January | Start under cover in late August, or sow direct from September once the soil warms and frost risk is over. Last sowing January. |
| Melbourne & Victoria | October to December | Frost tender. Sow direct Oct to Dec once frosts finish in mid September and the soil warms. Same season as zucchini. |
| Adelaide & SA | September to November | Sow Sep undercover or Oct to Nov direct after frost. Same season as zucchini; avoid midsummer sowings into extreme heat. |
| Perth & WA | August to October | Sow Aug to Oct like zucchini. The SEQ style summer sowings arrive too late to establish before the mid November deadline. |
| Tasmania | October to December | Sow Oct to Dec after frost. Button squash crop well in the short warm window. |
| Canberra & ACT | November and December | Frost tender. Sow Nov to Dec after the last frost in early November. Harvest before the April frosts. |
| North Queensland | April to August | Dry season Apr to Aug, same as zucchini. The SEQ spring and summer window lands in the monsoon. |
| Darwin & Top End | April to August | Dry season only Apr to Aug. NT Darwin calendar lists button squash. SEQ baseline of Aug to Feb lands in the build up and monsoon. |
Not to be confused with: Pumpkin and butternut, which are winter squash grown to full maturity and stored. Summer squash are picked young and tender, and Zucchini is a close relative grown the same way.
Where to plant
Squash need full sun and rich, well-drained soil with plenty of compost or manure. Sowing on a low mound helps drainage and warms the soil. Bushes spread a metre or so, and good air flow between them helps keep powdery mildew at bay.
They are frost tender and the seed needs warm soil to come up.
- South East Queensland: sow from August to February. Northern Rivers: September to February.
- Sydney: sow from September to January, or start under cover in late August.
- Melbourne and Hobart: sow from October to December, once frosts have finished and the soil is warm. Button squash crop well in Hobart's short warm season.
- Adelaide: sow from September (under cover) to November; avoid sowing into midsummer heat.
- Perth: sow from August to October so plants establish before the summer heat.
- Canberra: sow in November and December after the last frost and harvest before the April frosts.
- North Queensland and Darwin: sow in the dry season, from April to August, as wet season sowings struggle in the monsoon.
How to plant
- Dig compost or manure into the bed and make low mounds about 70 to 80 cm apart.
- Sow three or four seeds about 2 cm deep in each mound.
- Water in and keep the soil just moist. Seedlings appear in about a week in warm soil.
- Thin to the strongest one or two seedlings per mound.
- Mulch around the plants once they are growing well.
Watering and feeding
Water deeply and regularly, especially in hot or windy weather, at the base of the plants rather than over the leaves. Wet leaves encourage powdery mildew, and uneven watering can cause blossom end rot on the fruit.
Feed well. Dig in compost before planting, then give a liquid feed every week or two. Once fruit starts to set, a fertiliser higher in potassium supports cropping better than more nitrogen.
Pruning and care through the year
- Squash have separate male and female flowers. The female flowers have a tiny fruit behind the petals. Bees do the pollinating, so encourage them with flowers nearby.
- If young fruit shrivels and drops, pollination is failing. Hand pollinate early in the morning: pick a male flower, remove its petals and brush it over the centre of an open female flower.
- Remove leaves badly affected by powdery mildew to keep air moving through the bush.
Harvesting
Start picking about six to eight weeks after sowing. Pick button squash small, from about golf-ball size, while the skin is still glossy and soft enough to mark with a fingernail. Cut them off with a short stalk.
Pick every couple of days. Regular picking keeps the plant flowering, while fruit left to grow large slows new fruit from forming. Squash keep about a week in the fridge.
Growing in pots
Button squash suit a large pot at least 40 cm wide and deep, with a quality potting mix. Water every day in hot weather and feed weekly.
Using it
Steam, roast, grill or stir-fry small squash whole or halved. Larger ones can be stuffed and baked. Squash flowers can also be eaten, stuffed and fried, though picking female flowers means fewer fruit.
Varieties
- Button (Pattypan)
- Scallopini
- Spaghetti Squash
- Gem Squash
- Yellow Crookneck
Companion planting
Squash share the classic summer bed with corn and beans, and flowers nearby bring in the bees they need.
Good companions
- Corn Part of the traditional three sisters planting with beans, sharing the same warm season.
- Beans A summer legume that adds nitrogen and shares the warm bed.
- Nasturtium Draws aphids away and brings in bees for pollination.
- Marigold Bright flowers that bring in pollinators and beneficial insects.
- Borage Its blue flowers are very attractive to bees, which squash need.
Keep apart
Avoid planting these close to squash.
Pests and diseases
Powdery mildew is almost certain by late summer. Watch for leaf-eating beetles and, in warm areas, fruit fly.
Pests to watch for
- 28-spotted ladybird Orange ladybirds with many black spots, and their spiny yellow larvae, scraping lacy patches on the leaves.
- Aphids Clusters under the leaves and on new growth; they can spread viruses.
- Fruit fly Sting marks and soft, rotting patches in the fruit in fruit fly areas.
- Pumpkin beetle Orange beetles chewing holes in young leaves and flowers.
Diseases to watch for
- Powdery mildew White, powdery patches on the leaves, worst from mid summer. Water at the base and keep air moving.
- Downy mildew Angular yellow patches on the upper leaf with grey growth underneath in humid weather.
- Blossom end rot A dark, sunken patch at the flower end of the fruit, linked to uneven watering.
Common questions
Why are my baby squash rotting and falling off?
Usually poor pollination. The tiny fruit behind a female flower only grows if bees carry pollen to it. Plant flowers to draw bees, or hand pollinate early in the morning with a male flower.
When should I plant squash in Australia?
In spring and summer once the soil is warm: from August to February in South East Queensland, September to January in Sydney, and October to December in Melbourne and Hobart. In the tropics, sow in the dry season from April to August. Pick your region at the top of the page.
When do I pick button squash?
Small, from about golf-ball size, while the skin is still glossy and soft. They are usually ready six to eight weeks after sowing. Pick every couple of days.
What is the white powder on my squash leaves?
Powdery mildew, a fungal disease that almost always appears from mid summer. Water the soil rather than the leaves, give plants space, and remove badly affected leaves.
Is squash the same as zucchini?
They are close relatives and are grown the same way. Zucchini is a long summer squash; button or pattypan squash are round and scalloped.
Can I grow squash in a pot?
Yes, compact button types grow well in a pot at least 40 cm wide and deep with rich potting mix, daily water in summer and a weekly feed.
Sources we checked: Yates: How to grow squash; Sustainable Gardening Australia: Zucchini.