How Long Does Corn Take to Grow? Sweet Corn in Australia
Updated October 2026
A warm-season fruiting crop for the home garden
Growing Sweet Corn rewards a little local know-how, and in the right season the plants do most of the work for you. It is rated intermediate to grow. Saves ~$2-4/cob, homegrown corn is dramatically sweeter than supermarket.
This guide covers when to plant Sweet Corn in your region, the position and soil it likes, how to sow and space it, day-to-day care, the pests and diseases to watch, and how to harvest and store your crop.
🌱 Plant profile: Sweet Corn, with sowing times for your region, companion plants and common pests.
When to Plant Sweet Corn in Your Region
Sweet Corn is a warm-season crop, frost-tender and needs a frost-free run. In subtropical South-East Queensland it is sown in August, September, October, November, December, January and February. Timing shifts with your climate, so choose your region below for a local calendar.
Sweet corn is sown into warm soil after frost in the south and in the dry season in the tropics. These are the sowing months for each region from our planting data. Each region links to its full vegetable planting calendar, and the Sweet Corn plant page has spacing, companions and care notes for your region.
| Region | Sow seed | Local note |
|---|---|---|
| South East Queensland | August to February | Sow Aug to Feb. Plant in a block of several short rows for good pollination. |
| Northern Rivers NSW | September to February | Sow Sep to Feb. Inland, wait until the frost risk has passed, because a late frost cuts corn seedlings down. |
| Sydney & Coastal NSW | September to January | Sow Sep to Jan. The season is shorter than in Brisbane. |
| Melbourne & Victoria | October to December | Sow direct Oct to Dec once soil 20°C+. Frost-tender; Feb to Apr harvest before autumn frost. No winter sow. |
| Adelaide & SA | September to January | Sep starts undercover only. Direct sow Oct to Jan into warm soil in blocks for pollination. Water deeply through summer. |
| Perth & WA | August and September | Sow Aug to Sep only. Sweet corn fails in extreme summer heat and does best established in spring. |
| Tasmania | October to December | Sow Oct to Dec in the warmest spot. Early varieties only, cool summers slow ripening. Block plant for pollination. |
| Canberra & ACT | November and December | Sow Nov to Dec into warm soil after the last frost in early November. Choose early maturing varieties; plant in blocks for pollination. |
| North Queensland | April to November | Dry season crop in NQ. Bowen and the Burdekin plant sweet corn Apr to Nov. Avoid the Dec to Mar monsoon peak. |
| Darwin & Top End | March to August | Dry season main window Mar to Aug per NT growers. A November sowing for a wet season crop is possible but risky. |
Varieties to Try
Honey Sweet F1
Australian favourite supersweet. Tall, vigorous, fat yellow cobs. The Bunnings punnet standard.
Try: Yates, Mr Fothergill's, Bunnings
Balinese
Purple and yellow kernels on small cobs. Heirloom, not as sweet but striking. Kids love it.
Try: Eden Seeds, Green Harvest
True Gold
Old-fashioned sweetness, less sugary than supersweets, more corn flavour. Eden Seeds heirloom.
Try: Eden Seeds, Diggers
Popcorn (Strawberry)
Small red cobs that dry down for popcorn. Ornamental AND functional. Same care as sweet corn.
Try: Eden Seeds, Green Harvest
Position and Soil
Give Sweet Corn full sun (at least 6 hours a day). It does best in free-draining soil with a pH around 6 to 7. Dig through plenty of compost before planting, and mulch to hold moisture and keep weeds down. It needs an open garden bed rather than a pot, getting too big or deep-rooted for containers.
Sowing and Spacing
Sow seed about 3 cm deep. Thin or space plants to about 30 cm apart. Seedlings usually appear in around 7 days, fastest when the soil is between 18 and 32 degrees.
Plant in a block (not a row) of at least 4×4 for proper wind pollination. Hungry feeder, dig manure in first.
Care
Water consistently, roughly 10 L per plant every 2 days in warm weather, less in cool or wet spells. Feed every few weeks through the growing season with a balanced organic fertiliser, and keep mulch topped up.
Pests and Diseases
Keep an eye out for Corn earworm and Heliothis. The main diseases to watch are Rust, Smut and Northern corn leaf blight. Good spacing, watering at the base rather than over the leaves, and crop rotation prevent most problems. See our Pest and Disease Guide to identify and fix any issue.
How Long Does Corn Take to Grow?
Sweet corn takes about 90 days, roughly three months, from sowing to harvest, according to our plant data. Seedlings appear in about 7 days in warm soil, between 18 and 32°C, and the rest of the time goes into growing tall, flowering and filling the cobs. Each plant usually gives 1 to 2 cobs.
From seed to cob, stage by stage
- Germination, about a week. Seed sown 3 cm deep into warm soil comes up in about 7 days. In cold soil it is slow and can rot, which is why our calendars wait for the soil to warm.
- Leafy growth. The plants grow quickly towards their full height of 1.5 to 2.2 metres. Feed with nitrogen as they grow tall and keep the water up.
- Tassels and silks. The tassels at the top shed pollen onto the silks below, and the wind carries it between plants. This is the stage when steady water matters most, and when planting in a block pays off with fully filled cobs.
- Filling the cobs. The kernels fill and sweeten in the last weeks. A cob is ready when the silks have turned brown and a kernel pressed with a thumbnail runs milky rather than clear.
Count about three months from your sowing date to plan the harvest. In Melbourne, sowings from October to December are picked from February to April, before the autumn frost. Short-season regions such as Tasmania and Canberra do best with early varieties, because cool summers slow ripening.
Harvesting and Storing Sweet Corn
Sweet Corn is typically ready to harvest in around 90 days (about 3 months). Fridge in husk, use within 2 days for best sweetness. Blanch and freeze kernels.
Twist each ripe cob down and off the stalk, and eat it as soon as you can, because the flavour is best used soon after picking.
In the Kitchen
In the kitchen, sweet corn is good grilled on the BBQ with butter, kernels cut for salads and salsas, made into fritters or corn chowder and roasted and eaten straight from the cob. Nutritionally: good source of carbohydrates and fibre and contains lutein for eye health.
Companion Planting
Sweet Corn grows well alongside Beans, Pumpkin, Zucchini and Cucumber. Keep it away from Tomato. Our companion planting chart has the full pairings.
Frequently Asked Questions
When should I plant Sweet Corn in Australia?
Sweet corn is sown once the soil is warm and frost has passed. South East Queensland sows from August to February, the Northern Rivers from September to February, and Sydney and Adelaide from September to January, with Adelaide's September sowings started under cover. Melbourne and Tasmania sow from October to December, Canberra in November and December, and Perth in August and September only. In North Queensland sow from April to November, and in Darwin from March to August, avoiding the monsoon.
How long does Sweet Corn take to grow?
About 90 days, roughly three months, from sowing to harvest, according to our plant data. Seedlings appear in about 7 days in warm soil. The cobs are ready when the silks have turned brown and a kernel pressed with a thumbnail gives milky juice.
Can I grow Sweet Corn in a pot?
It is best grown in an open garden bed rather than a pot, needing more root room than a container gives.
How much sun does Sweet Corn need?
Give it full sun (at least 6 hours a day) for the healthiest growth and best harvest.
How do I know when sweet corn is ready to pick?
Check when the silks have turned brown, about three months after sowing. Peel back a little of the husk and press a kernel with your thumbnail: milky juice means it is ready, and clear juice means it needs longer.
How many cobs do you get per corn plant?
Usually 1 to 2 cobs per plant, according to our plant data. Planting in a block of several short rows rather than one long row gives better pollination and fuller cobs.
Why are my corn cobs only half filled?
Gappy cobs come from poor pollination. Corn is wind pollinated, so plant in a block of several short rows rather than a single line, and keep the water steady through tasselling and silking.
When is it too late to plant sweet corn?
Perth stops sowing at the end of September, Melbourne, Tasmania and Canberra at the end of December, Sydney and Adelaide at the end of January, and South East Queensland and the Northern Rivers at the end of February. Later sowings run out of warm weather before the cobs fill.
See also: Sweet Corn in the Plant Library
Plant profile
The sweet corn profile has sowing times for your region, companion plants and common pests.
