Sweet corn
Vegetable · warm season · also called maize
When to plant
- Sow seeds outdoors about 1 week after your average last spring frost.
- Ready to harvest about 75 days after planting.
- Sow again every 2 weeks for a steady harvest.
Plant in blocks of 4+ rows for pollination.
Frost dates depend on where you live. Enter your ZIP code to get exact dates.
Dates by zone: 3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a 8b 9a 9b 10a 10b
Growing basics
- Sun
- Full sun (6+ hours)
- Spacing
- 8–12 in, in blocks
- Soil temperature
- At least 60°F
- Time to harvest
- About 75 days
- Plant family
- Grass family
- Harvest per plant
- About 0.5 lb
- Seeds keep
- About 2 years
Companions
Good neighbors: Green beans (bush), Pole beans, Winter squash, Pumpkin, Cucumber
Keep apart: Horseradish. Horseradish spreads aggressively. Give it its own spot.
Keep apart: Mint. Mint spreads aggressively into neighbors. Keep it in a pot.
Keep apart: Fennel (bulb). Fennel slows the growth of most garden plants. Grow it on its own.
Keep apart: Sunchoke (Jerusalem artichoke). Sunchokes spread aggressively and shade neighbors.
Varieties to try
- Early Sunglow 63 days: early, short stalks
- Golden Bantam 78 days: heirloom yellow
- Peaches and Cream 83 days: bicolor, sweet
- Silver Queen 92 days: white, late
Pests and problems
Grow it well
Tips
- Test sweet corn with a fingernail. About 3 weeks after the silks appear, once they've turned brown and dry, peel back the husk and press a kernel. Milky juice means it's ready. Clear juice means wait a few days; no juice means it's past its best.
- Plant corn in a block, not one long row. Corn is pollinated by the wind carrying pollen from the tassels to the silks. A block at least four rows wide gets full ears; a single long row gets ears with missing kernels.
- Feed hungry crops halfway through the season. Corn, tomatoes, squash, and cabbage use up nitrogen fast. When tomatoes set their first fruit, or corn is knee-high, scratch a little compost or balanced fertilizer into the soil beside the plants and water it in.
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