How to Grow Corn
Corn At a Glance
Difficulty
Moderate
Category
Grain
Sun Exposure
Full Sun
Frost Tolerance
Frost Tender
Cold Hardiness
Survives to 2°C
Plant Family
Poaceae
Growing Season
Warm Season
Plant Lifecycle
Annual
How to Start It
★ Recommended for beginners
Sow 1 to 2 weeks after your last spring frost, once the soil is warm, because corn seed rots in cold soil. Plant seeds 2 cm deep and 25 cm apart in a square block of at least 4 short rows, never one long row. They sprout in 5 to 10 days. The block matters: corn is pollinated by the wind, and plants close together catch each other's pollen to fill the cobs.
Corn takes about 90 days from sowing to picking, so it needs warm soil and a full summer. Ornamental corn is grown for its colourful dry cobs, not for eating fresh like Golden Bantam sweet corn. Grow them far apart, since pollen from ornamental corn makes sweet corn kernels starchy and tough.
When To Start
First chance to plant
10 Days After Last Frost
Last chance to plant
60 Days Before First Frost
When should you plant Corn?
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Your Corn Planting Window
Start planting
May 15, 2026
Last chance
Sep 10, 2026
Your Corn Calendar
Set your location to turn these into exact dates and reminders.
Sow corn outdoors in a square block, not one long row
1 week after your last frost· every year
Pick corn when the silks are brown and a kernel runs milky
80 days after your last frost· every year· optional
Did you water your corn seedlings today? Keep the top of the soil damp until they are up and growing.
About 1 days after you plant it
How is your corn patch doing? Water deeply at the base, since corn drinks a lot as it grows.
About 40 days after you plant it
Corn check! Steady water now helps the ears fill out with full kernels.
About 70 days after you plant it
Picking time may be here: check your corn.
About 90 days after you plant it
The Journey Ahead
Corn's Lifecycle
Seedling
Mature Plant
Seed Production
Step 2
Planting & Sprouting
Expect sprouts in 5–10 days
Growing Tips
- 1Plant corn in full sun, at least 6 to 8 hours a day, out of strong wind.
- 2Dig plenty of compost into the soil before sowing, since corn is one of the hungriest crops in the garden.
- 3Water deeply about once a week, and never let the soil dry out when the tassels (the feathery tops) and silks (the threads at the end of the cobs) appear.
- 4Feed with worm castings or compost tea when the plants are knee high and again when the tassels show.
- 5Pile a little soil around the base of each stalk when it is knee high to help it stand up to wind.
- 6Raccoons and birds love ripe corn, so pick it as soon as it is ready, and pull off any small caterpillars you find in the tips of the cobs.
Seedling Phase
Step 3
Growth & Maturity
~90
Days to Maturity
250 cm
Mature Height
60 cm
Mature Width
Pests to Watch For
Diseases to Watch For
Mature Plant
Step 4
Harvesting
Harvest Window
21 days
When to Pick
Pick ears when silks dry and kernels are full
How to Harvest
- 1Sweet corn is ready about 3 weeks after the silks appear, when the silks are brown and dry and the cob feels full to the tip.
- 2Peel back a bit of husk and press a kernel with your fingernail: milky juice means it is ready.
- 3Hold the stalk with one hand, then pull the cob down and twist it off with the other.
- 4Eat or chill it the same day, because its sugar turns to starch within hours of picking.
- 5Leave ornamental corn on the stalk until the husks are dry and brown, then pick it and hang it somewhere airy to finish drying.
Step 5
Saving Seeds
How to Save Seeds
Corn is pollinated by the wind and crosses easily with any other corn, so grow only one variety, or keep different kinds at least 400 m apart. Save seed only from a variety that is not a hybrid, like Golden Bantam, since hybrid F1 seeds will not grow true. Corn grown from the seed of just a few plants gets weaker over the years, so save from as many healthy plants as you can, at least 20, and mix the seeds together. Leave the chosen cobs on the stalk until the husks are brown and dry, then hang them indoors for another 2 to 3 weeks. Twist the kernels off and store them in a labelled jar somewhere cool, dark and dry, where they keep about 3 years. Dry sweet corn seeds look wrinkled, which is normal.
Seed Production
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