In the northern Great Plains, planting cover crops after a full-season cash crop often results in a poor or marginal stand due to low temperatures and/or dry soils. Greater stand establishment and growth has been obtained if the cover crop follows a short season crop or if it is interseeded into corn or after or soybean in mid-July. Planting cover crops in these situations is when herbicide residuals may be the most hazardous for cover crop establishment. A greenhouse study examined radish or rye growth in silty clay loam and silt loam where corn herbicides had been applied 120 days prior to collection.