With the increased interest developed during the past few years on production of alfalfa hay for cash sales, the acreage seeded each year has increased • And. although UK forage specialists prefer spring seeding of alfalfa to fall seeding. some growers will and should opt for fall seeding. This is particularly true on fields which have a history of legumes and/or are contaminated with Johnsongrass. Those who do so should begin planning now to have the seedbed prepared for planting by mid-August to mid-September.
Wells, Kenneth L. and Evans, J. Kenneth, "Seedbed Preparation for Fall Seeded Alfalfa" (1987). Soil Science News and Views. 132.