Sweet corn is an annual with yellow, white, and bi-colored ears. A long, frost-free growing season is necessary after planting. Sweet corn is wind-pollinated, so it should be planted in blocks, rather than in single rows. Early, mid, and late-season varieties extend the harvest. If you miss the optimal harvest time, corn will go downhill fast, as sugars convert to starch.
Planting, Growing, and Harvesting Sweet Corn
- Corn plants are picky about their soil. Work in aged manure or compost the fall before planting and let over winter in the soil.
- Starting corn seeds indoors is not recommended.
- Plant seeds outdoors two weeks after the last spring frost date.
- Make sure soil temperature is above 60 degrees F for successful germination. (Up to 65 for super sweet varieties.) In colder zones, the ground can be warmed by a black plastic cover if necessary. Plant seeds through holes.
- Plant seeds 1 inch deep and 4 to 6 inches apart. Rows 30 to 36 inches apart.
- For sufficient pollination, plan your plot right. Don’t plant two long rows, rather, plant corn blocks of at least four rows.
- You may choose to fertilize at planting time; corn is meant to grow rapidly. If you are confident that the soil is adequate, this can be skipped.
- Water well at planting time.
- When your plants are 3 to 4 inches tall, thin them so they are 8 to 12 inches apart.
- Be careful not to damage the roots when weeding.
- Soil must be well drained and able to keep consistent moisture.
- In dry conditions, be sure to keep corn well watered due to its shallow roots. Water at a rate of 5 gallons per sq yard. Mulch helps reduce evaporation.
- Harvest when tassels begin to turn brown and cobs start to swell. Kernels should be full and milky.
- Pull ears downward and twist to take off stalk.
- Sweet corn varieties lose their sweetness soon after harvesting.
- Prepare for eating or preserving immediately after picking.
- Sweet corn freezes well, especially if removed from ears before freezing. Learn how to properly freeze corn.
- Corn kernels can also be harvested for other purposes, like corn-filled therapy packs.
There are three types of sweet corn: Normal, sugar-enhanced, and super sweet. Each one contains a different level of sucrose, changing the flavor and texture of the corn. Sweeter varieties will stay sweeter for longer after harvest.
- ‘Lochief’: Midseason, normal-sugar variety. Yellow.
- ‘Silver Queen’: normal sugar-variety. Resistant to some bacterial diseases. White.
- ‘Challenger Crisp n Sweet’: supersweet variety, resistant to some diseases, high yield. Yellow.
- ‘Pristine’: sugar-enhanced variety, good taste. White.
Wit & Wisdom
- Baby corn is produced from regular corn plants that are harvested early, while the ears are immature. Regular sweet corn, sugar-enhanced sweet corn, and supersweet corn varieties can be used, along with a few varieties that are specific for baby corn.
- If your corn shucks harder than usual, prepare for a cold winter.
- Corn is one of the Three Sisters; its growing style pairs perfectly with beans and squash. Learn more about companion planting.
- Corn is great for eating but also has so many other uses including medicinal. Learn more about corn for natural health.
- Learn more fun, witty facts about corn.
If too much hot pepper or spice has been added to a soup or stew, adding a can of sweet corn can help.
Popcorn is also a favorite snack if you have leftover kernels. Learn how to make homemade popcorn here.