Sweet corn should be planted after the last frost when the soil and air temperatures are warm enough to support growth. For most temperate regions:
- Start sweet corn seeds indoors in mid-April and transplant seedlings outdoors 2 to 3 weeks later after the danger of frost has passed.
- If planting directly outdoors, sow seeds from the end of April to the end of May when frost risk is gone, and soil temperatures reach at least 10°C (50°F), ideally around 20°C (68°F).
- Plant seeds about 3 cm deep, spacing plants about 34 to 45 cm apart in groups for better pollination.
- Late May to early June is a typical time to plant sweet corn outdoors in milder climates without frost risk.
- For a continuous harvest, stagger planting every two weeks or plant early, mid, and late maturing varieties.
In warmer or tropical zones, sweet corn can be planted year-round, while in cooler zones, planting is advised around spring to early summer to ensure a sufficient growing season for the cobs to mature.
