In the second and succeeding seasons, the first harvest may be taken in the full bud stage, with other harvests being made at 10 percent bloom or before crown buds advance. Always allow the last growth in any season to grow and store the full amount of food reserves in the tap root before being killed by freezing temperatures. This provides the energy for the new plants to grow the following spring. After complete kill by cold, the remaining frosted growth may be removed by harvesting or grazing. Chemical Weed Control Controlling weeds is sometimes a major problem in growing alfalfa, especially on early fall and spring seedings.
Weeds can emerge in such numbers that they reduce the alfalfa stand.
In some cases, you can get a more uniform and productive stand of alfalfa by using herbicides to prevent weed problems. However, most seedings made between September 1 and October 15 will not require a herbicide to control weeds. There are several preplant and postemergence herbicides for weed control in alfalfa. Current information on chemical weed control can be found in the forage section of MSU-ES Publication 1532, Weed Control Guidelines for Mississippi , and in Extension Information Sheet 945, Forage Weed Control in Pastures . County Extension agents can assist with this information when needed.