From sowing to harvest, Hickory King corn plants need 110 to 115 days of frost-free growing season. Corn matures slightly earlier if humidity is high and summertime heat abundant.
Corn is a tropical annual grass and does not tolerate any frost. Sow seeds after danger of spring frost passes and soil warms to at least 65 degrees Fahrenheit. Drought slows plant growth and quality of the corns and kernels.
Harvest Hickory King corn cobs around 85 days when the kernels are still soft and immature but in the "milking" stage. Eat the kernels like sweet corn. More mature kernels contain higher levels of starch.