Cover crops seeded into or after fall-harvested crops can be beneficial for the soil, but can present challenges for seeding the covers. Fall mixtures vary greatly depending on your goals, planting method, and timing. Here are some basic guidelines to follow:
Planting 4-5 weeks prior to first frost
You can plant any cool season or fast-growing warm season species during this time frame and obtain significant amounts of biomass production prior to freezing weather. In many central and northern areas, this may require broadcast seeding prior to fall harvest. This time frame is also an ideal window to plant perennial grasses and forbs.
Planting 2-3 weeks prior to first frost
Cool season species that winterkill at temperatures below 25°F or overwintering species are good choices for this window.This is an ideal time to plant any overwintering crop that will be utilized for forage or seed production the following year.
Planting at or after first frost
With limited heat units remaining in the season, only invest in species with overwintering potential. Fall growth will be limited and winter hardy cereal grasses will most commonly be utilized. Winter hardy legumes can be added if there is adequate time for spring growth prior to the next planted crop.
Timing of termination in the spring is an important management decision that will have to be made.
Elbon cereal rye is the best option for late planting as it has the most fall growth and the fastest spring growth of any cereal grain we have ever tested. It has excellent winter hardiness, good grazing when it is young, and is unsurpassed for weed suppression of winter and spring annuals. Elbon grows fast enough in the spring that it is also the best option if you are considering roller crimper termination of the cover crop. Hairy vetch is the best fall seeded legume option, but you need to be willing to let this legume grow until late April–mid May to get enough nitrogen production to offset the seed cost.