When to plant
Sow direct after last frost when soil is above 15°C. Corn is frost-tender and grows best in warm summers. For continuous harvest, plant every 2–3 weeks rather than all at once. Minimum planting size: 4 rows of 10 plants for adequate wind pollination.
Soil & site
Corn needs deep, fertile, well-drained soil. pH 5.8–6.8. Work in abundant compost and a high-nitrogen fertilizer before planting. Corn is a very heavy feeder. Plant in blocks (not single rows) of at least 4 rows for good wind pollination.
Feeding
Apply a nitrogen-rich fertilizer at planting. Side-dress with additional nitrogen when plants are 30 cm tall and again when they reach 60 cm (the "knee-high" stage). Consistent nitrogen throughout the season is critical — deficiency causes pale striped leaves and poor ear fill.
Common problems
Corn earworm (caterpillar in the ear tip — apply a drop of mineral oil to the silk 3–7 days after silk appears). European corn borer. Smut (grey-black galls on ears and stalks — remove and destroy affected parts immediately). Birds and raccoons raiding ears near maturity — cover with paper bags or netting.
When to harvest
Sweet corn is ready when the silk turns dry and brown (but the husk is still green), and the ear feels plump when squeezed. Peel back a small section of husk and pierce a kernel with your thumbnail — milky juice means it's ready. Watery = too early, doughy/starchy = too late. Corn has a very short harvest window of 2–3 days.
How to harvest
Grasp the ear firmly and snap downward with a quick twist. The ear should break cleanly from the stalk. Check the entire planting every day once the first ear is ready — timing is critical. Cook or refrigerate within hours of harvest for the sweetest flavour.
Storage & use
Corn loses its sweetness rapidly — sugars convert to starch within hours at room temperature. Eat the same day as harvest if possible. For storage, blanch cobs 4 minutes, cool in ice water, cut off kernels, and freeze. Frozen sweet corn retains most of its flavour for up to a year.
Useful for growing sweet corn
A few things that make this one easier — chosen for this plant, not a generic list.
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