 If you follow along on your Almanac calendar, you'll find mid-July always has this notation. Corn scadius air is everywhere. Don't bother looking it up in the dictionary, it's not there. But most of us know it by intuition, the hot and damp conditions that are ideal for growing corn. And if you're growing your own sweet corn, here's a few signs it's ready for picking. The silk will have turned brown, the ears will be plump and full, and the top of the ears should feel rounded, not pointy.