Cover crops serve several purposes. A site that is being prepared by cultivation for planting natives the following year may be subject to soil erosion or weed invasion. If so, a cover crop planted in the summer will help hold soil in place and/or suppress weeds. If only a cover crop is being planted, a heavy seeding is recommended. A cover crop planted with native seed requires a much lower seeding rate. See each cover crop below for specific lbs/acre recommendations.
Suggested Cover Crops: A good cover crop is Oats, which can be planted with prairie seed to stabilize the soil. This annual plant grows rapidly, and if not seeded too heavily, will not compete with the wildflowers and grasses. An oats cover crop will not reseed itself. You may be able to purchase Oats or Winter Wheat from local farm seed dealers for lower prices. If so, be sure there is no weed seed contamination listed on the label.
Another cover crop is Regreen, a wheat/wheatgrass hybrid that produces a sterile plant. After it dies out, it does not leave a new generation of plants to compete with slower-growing perennial species. Regreen is a highly versatile temporary cover crop that can be planted in either spring or fall in most climates.