Sweet Corn Essentials

by National Gardening Association Editors


  • Plant corn directly outdoors after all danger of frost has passed and the soil temperature is about 60&deg F.
  • Seeds can be started indoors, two seeds per peat pot, 3 to 4 weeks before the last frost date.
  • Plan the garden to prevent cross-pollination between incompatible types of corn and to prevent tall varieties from shading nearby crops.


  • Work plenty of manure into the soil the previous fall.
  • Just before planting, sprinkle 3 to 4 pounds of 5-10-10 or equivalent fertilizer per 100 feet of row along the side of each row and work it into the soil.


  • Plant corn seeds in blocks of at least four rows with 2 to 4 feet between rows (the closer spacing is for short varieties). Sow the seeds 1 1/2 to 2 inches deep, 6 to 8 inches apart.


  • Thin the corn to stand 12 to 16 inches apart when the plants are 4 to 5 inches tall.
  • Provide at least 1 inch of water a week.
  • Control weeds with frequent shallow cultivation until the plants are knee high. Then apply a 3- to 5-inch layer of mulch.
  • Side-dress with a high-nitrogen fertilizer, such as 2 pounds of ammonium nitrate per 100 feet of row, when the plants are 8 to 10 inches tail and again when the silks appear.
  • Watch for signs of nitrogen deficiency (yellowing leaves) and respond with quick side-dressings of fish emulsion, manure, commercial fertilizer, or a combination of the three.
  • See our article Summer's Bad Guys by Charlie Nardozzi for controls of common corn pests such as corn earworms and European corn borers.


  • Sweet corn should be harvested when its ears are completely filled out and a pierced kernel shows a milky white liquid.
  • Sweet corn varieties (except for supersweet varieties) lose their sweetness soon after harvest. Immediately after picking prepare the ears for eating or preserving.
  • Harvest corn for meal or popping as late as possible and dry on the cob, then store.

How to Have the Earliest Corn Table of Contents

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