One favorite sweet corn variety can be sown two weeks later than the first sowing to extend the harvest of fresh sweet corn. The second sowing will mature about two weeks later than the first. This extended fresh harvest will allow gardeners a longer time to eat fresh sweet corn. The fun begins when the corn comes in. It is true for some varieties but not all.
Sweet corn has a very high percentage of sugar and water in the composition of the kernels.
Most varieties of sweet corn are ready to eat in two and a half to three weeks after pollination. Very hot temperatures will hasten the maturity of the corn in the garden. To check for picking, examine the kernels and pop one of the kernels with your thumbnail. If the juice spurts out and looks milky, harvest. If the juice is clear, wait another day.