Grow Guide Conditions:
Corn is a heavy feeder, and may be grown in a wide range of soil types with a pH of 5.5–7.0 and good fertility. It is a warm season crop sensitive to cool soil conditions. Always grow different types of corn (su/se sweet corn, sh2 super sweet corn, and popcorn and starch types) separated from each other by an isolation distance of at least 100’. Cross pollination between types makes kernels starchy and tough. In addition, since corn is wind pollinated and the pollen may travel one mile or more, isolate from genetically modified varieties to ensure crop integrity.
Grow Guide Seed:
Corn is most commonly direct seeded, but can also be started in cell trays indoors for better germination and an earlier crop. Corn seed will rot in cool soil, so wait until soil temperatures reach 60-65°F before direct seeding. Plant in blocks for optimum pollination, and sow every 2-3 weeks until midsummer for continuous harvests. Plant seeds 1 inch deep, 3-4 inches apart, allowing 36-48 inches between rows. Thin to one plant every 8-12 inches. To start seedlings indoors, fill 1-1/2 inch cell trays with a sterile seed starting mix. Plant 1 seed per cell, 1/2 inch deep. Ideal soil temperature for germination is 75-85°F. Transplant 3-4 week old seedlings outside after all danger of frost has passed, 8-12 inches apart, allowing 36-48 inches between rows.
Grow Guide Pests:
Practice crop rotations. Destroy or incorporate crop residue to control leaf blights, root worm and European corn borer. Stewart’s Wilt, a serious bacterial disease, is spread by the flea beetle and can be difficult to manage in areas of heavy flea beetle pressure. Use Bacillus thuringiensis (Bt) for suppression of corn ear worms or cut off damaged portion of ears prior to eating.
Grow Guide Harvest:
Corn begins converting its sugars to starch as soon as it is picked. Normal sugary (su) varieties are best consumed within a few hours of picking. Sugary enhanced (se) varieties will retain their sweetness for several days after picking. Harvest when the silks are dried brown and the ears feel plump to the tip.