Cover crop species recommendations change depending on whether you are in Northern or Southern Wisconsin.
Northern Wisconsin Cover Crop Options
Small grains / grasses
Cereal rye is the only option for seeding cover crops after corn for grain in Northern WI but it should be planted by late October. Much later than this and rye won’t have a chance to grow enough to survive the winter. With sufficient snow cover and fall growth, cereal rye will survive the winter and require termination in the spring.
Brassicas
Due to limited time for establishment and growth, it is not recommended to plant any of the brassicas after corn grain. There is not enough growing degree days left in the season to provide any cover crop benefits.
Legumes
Due to limited time for establishment and growth, it is not recommended to plant any of the legumes after corn grain. There is not enough growing season for them to develop nodules and fix nitrogen.
Southern Wisconsin Cover Crop Options
Small grains / grasses
Cereal Rye and triticale are both cover crops that can be planted into October in Southern WI. Rye is more winter hardy than triticale so for very late planting dates, rye is preferable. Rye should be planted by late October, much later than this and rye won’t have a chance to grow enough to survive the winter. With sufficient snow cover and fall growth, cereal rye will survive the winter and require termination in the spring.
Other grasses, such as annual ryegrass. oats, barley are generally not recommended for planting after corn grain because they will winterkill and there are not sufficient enough growing degree days after grain harvest for these cover crops to produce enough residue to protect the soil in the spring. However, if these grasses are planted sometime during the corn growing season, they may be options. Please see the aerial seeding and interseeding pages to read more about these options.
Brassicas
Due to limited time for establishment and growth, it is not recommended to plant any of the brassicas after corn grain. There is not enough growing degree days left in the season to provide any cover crop benefits.
Legumes
Due to limited time for establishment and growth, it is not recommended to plant any of the legumes after corn grain. There is not enough growing season for them to develop nodules and fix nitrogen.
