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COVER CROP MIXES

It has been observed that a mixture of plants often performs tures consist of both cool season and warm season species
better than a monoculture of the best performing plant in so soil temperatures need to reach and maintain 55-60°F
the mix. Each plant species has unique liquid carbon root and the last frost risk has passed.
exudates which feed a diverse community of microbes, Midsummer Mixes
which in turn makes the whole system work. This is one of Planting covers after a summer-harvested cereal or pea crop
the reasons we try to create diverse cover crop mixtures in- is the perfect opportunity to implement very diverse cover
stead of just picking the highest yielding or the “best ones”. crop mixes into a cropping system. Converting the ample
Plant diversity also provides different root types for better hours of summer sunlight into forages and soil nutrients is
use of soil resources, a layered canopy for better capture one of the best ways to improve the biological health of your
of sunlight, better livestock nutrition for grazing, and far soil. With so many cover crop options to choose from, these
lower risk of any one insect or disease taking out the stand. mixes will be driven by your specific goals. These mixes can
Green Cover Seed is the leader in designing and delivering also work well for early silage fields and seed corn fields.
customized diverse cover crop mixes. We encourage you to Warm season species will dominate these mixes with a few
use the SmartMix® Calculator (see pages 56-57) to experi- strategic cool season species added for diversity.
ment with designing mixes, or call or email us and we will
help design the best mix for you. Here are some basics of
cover crop mixology.
Spring Planted Mixes Photo by Elizabeth Hesterberg
Spring plantings are commonly utilized to jumpstart soil
biology after a long cold winter. These cover crop mixes
are used to “prime” the soil biology ahead of a later spring
planted crop. Spring mixes are also used in the western
Great Plains as a “fallow replacement”, where a living cover
provides extra residue and biological diversity for the soil.
Moisture used by the cover crop is usually gained back
later in the summer through increased infiltration and de-
creased evaporation. These mixes can be seeded when soil Late Summer Mixes
temperatures maintain 40°F; however, greater diversity can In the late summer there is a terrific window of oppor-
be added to these mixtures if planting date is delayed until tunity for both warm and cool season species to be used
closer to the frost-free date. together. Warm season species will decline after the first
killing frost, leaving the cool season species to continue to
thrive and be productive.

Fall Mixes
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
Photo by Brett Peshek goals, planting method, and timing. Here are some basic

guidelines to follow:
Planting 4-5 weeks prior to first frost: Use any cool season
or fast-growing warm season species for significant amounts
Late Spring/Early Summer Mixes of biomass production prior to frost. In many areas, this
Late spring and early summer plantings are commonly uti- may require broadcast seeding prior to fall harvest.
lized as a forage source for livestock when summer heat Planting 2-3 weeks prior to first frost: Cool season species
begins to reduce cool season grass forage production. These that winter-kill at temperatures below 25°F or overwinter-
mixes can also be used on prevented planting acres to add ing species are good choices. This is also the ideal time to
biological diversity, suppress weeds, produce nitrogen, and plant overwintering crops for forage or seed production for
cycle nutrients during the prevented plant year. These mix- the following year.

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