Make Room for Corn (cont)
By: Jack Ruttle
Time to Plant
Another advantage of the shorter corns is that they tend to be early, maturing in 55 to 70 days. But corn seed sprouts slowly early in the season and can decay before the plant reaches the light. Corn germinates fastest when the soil temperature is around 90° F, but waiting until then means many of us couldn't mature a crop. You can plant normal corn varieties when the temperature at a depth of one to two inches reaches a minimum of 55° F (minimum temperature occurs around dawn). For supersweets and sugar-enhanced varieties, wait until the soil reaches 60° to 65° F. One of the reasons people traditionally plant two and even three kernels at each point is to overcome poor germination in early plantings.
If you want to push the season, the best way is to presprout the seed in moist paper towels inside a plastic bag. Or, start the corn indoors in containers about two weeks before your planting date and then transplant seedlings under plastic tunnels or Reemay.
Sweet corn is also an excellent candidate for late planting. You can pick corn from your garden long after the local market farmers have exhausted their plantings. Though corn is not very frost hardy, it grows well in the cooler weather of early fall, unlike other heat-lovers like tomatoes, eggplant or basil. You can pick the last crop of good corn the day before frost takes the planting.
Late planting means shorter corn. And corn varieties tend to be shorter the farther south you go. The reason is that shorter day lengths push the plant into the flowering stage earlier. So in the North, fall-crop corn may be a foot or so shorter than normal. In the South, varieties advertised as seven to eight feet tall in catalogs may stay under the rather arbitrary six-foot height limit in the chart, especially in later plantings.
When you plant corn after July 1, add 7 to 14 days to the ripening time to account for shorter, cooler days. All season long, separate your successive plantings, either by planting day or by days to maturity, by about two weeks. (One week isn't enough because maturity rates vary with temperature.)
More than most vegetables, corn likes rich soil. At planting time, apply two inches of compost or three pounds of soybean meal, alfalfa meal or 5-10-5 per 100 square feet. Use an organic mulch once the soil is warm.