Farmers selecting corn hybrids for silage should first consider planting the latest relative maturity of corn that will reach harvest maturity by frost. Higher yields are produced with hybrids that mature slightly later than those adapted for grain production – perhaps 5 to 10 relative maturity units later. These hybrids will result in the highest yield of high quality forage.

When planting is delayed beyond May 20, earlier maturity hybrids should be planted to reach harvest maturity by frost.

However there comes a point (about June 1 in northern Wisconsin and June 20 in southern Wisconsin) where planting is delayed to the extent that even shorter maturity hybrids will not reach harvest maturity by frost. At this point it is preferable to plant later maturity hybrids so they reach pollination at frost, and then allow drying after frost to get the hybrid to low enough moisture content for ensiling.

The recommendation to switch back to later maturity hybrids for late planted corn silage is made because corn has two peaks in forage quality: one at pollination and one at harvest maturity. The early peak in forage quality at pollination is high in quality but too wet for ensiling unless frost can dry the corn down. For late planted corn, aiming for a hybrid that will be at pollination at frost becomes a better choice than planting a short season hybrid that will not reach harvest maturity.