Seeding forages in the fall may seem like a good idea, but it should only be done as a last resort.
BrettYoung Forage Seed Specialist Kent Price has seen forages seeded in all kinds of ways and seasons, including many fall seeding attempts. Growers may decide to seed a new forage stand in the fall because they have the time to or because some land became available for seeding. They might do it because they simply didn’t have time to do it in the spring or because they’re trying to get ahead of spring weeds. Either way, fall seeding is rarely a first choice as it comes with a lot of risks and stress.
There are essentially two categories when fall seeding forages.
Fall establishment planted in early September is when seeds will germinate and need to establish before freeze-up, and seed planted in late October once the soil is cold will lay dormant till spring.
Risks of Seeding at the Start of September #
Most risks here come from seeding legumes, not grasses. Price said because forage grasses don’t need to be a certain size to overwinter, they’ll typically be fine if seeded around Sept. 1. They’ll have time to establish and make grass seedlings for the spring.
Seeding legumes at the start of fall, though, is usually a death sentence for the crop. Price said by Sept. 1, it’s too late for alfalfa, clover, and other legumes to establish themselves, so they won’t be big enough to survive the winter.
“Legumes take off in the spring with the energy from its root,” said Price. “If it doesn’t have a big enough root, it won’t have enough energy to emerge.”
Risks of Seeding in Late Fall #
Price said one of the most common reasons someone might seed a new forage stand at the end of October is because a low spot has become dry, and they have the time to get to it. Though those spots may be dry in the fall, they’re destined to become wet again come spring.
“These low spots are typically full of water in the spring,” said Price. “The seed will rot in the ground or flood out and be washed away. It’s just too wet of a scenario to establish the seed come springtime. The best time to establish these low areas is in the late spring or summer immediately after they become dry enough to work the soil.”
Even in better fields, dormant seeding is a significant risk. The extended period between planting and germination makes the seeds susceptible to wind and water erosion, and if you get a winter warm spell plants can emerge too quickly and die off when winter temperatures return. Legume plants die off if temperatures are colder than -5 degrees Celsius for a prolonged period of time.
Because of the risks, Price only recommends seeding forages in the fall as a last resort. And if you have to do it, he suggests planting grass — because of fall dews, the higher humidity at the soil surface will allow for good establishment.