Winter Wheat cover crop seeds produce hardy annual plants. Unlike oats, this cold-hardy cereal will not die off over winter. The germinated seeds lie dormant in frosty soil, and then burst into growth in the spring, providing a greater nitrogen to carbon ratio when it is tilled under. You will want a machine to help till Winter Wheat under, but it does not form the bomb-proof roots like fall rye. Left to mature, it will produce hard wheat kernels by early July. Hardy to Zone 3: -40°C (-40°F). 500g covers approximately 40m2 (438 ft²).