Corn varieties have been developed to reach maturity at different times. From 85 to 140 days after planting. Which variety is planted depends on how long the growing season is. In the northern states of the Corn Belt, they plant corn that matures in 80-92 days. Varieties developed for southern states will mature in 140 days. So, a year is not a year in the life of an ear! What part of the year is it?