Managing Seeding Year Alfalfa
Seeding year alfalfa is different from established stands and needs a different management and harvest strategy. Stems are spindly, roots are small and shorter, and growth is a little slower.
You can harvest seeding year alfalfa as early as 40 days after seedlings emerge. Notice that this is 40 days after emergence rather than after planting. It takes plants about 40 days to develop their ability to regrow from the crown after cutting. If plants are cut before this development takes place, maybe to control weeds, at least one set of leaves must remain on the plant for it to regrow.
Although alfalfa seedlings can be harvested 40 days after emerging, it’s better to wait until 60 to 70 days after emergence, at late bud to early bloom stage, before first cut. Yield will be a little higher and plants will withstand weather stress easier with a little extra growth. This extra time also allows roots to penetrate the soil more deeply, helping avoid problems from soil compaction or surface soil dryness.
These first harvest recommendations may be earlier than some folks like to cut. However, after this early cutting the regrowth of seedling alfalfa will become more similar to established alfalfa, giving you the opportunity for two or maybe even three cuts the first year. A delayed first cutting also helps with weed control.
One last point—never cut seeding year alfalfa during the four-week period before a killing freeze. Winter injury can be severe due to reduced winterhardiness. Look ahead at the calendar to plan when future cuts might be taken to avoid cutting during this sensitive time.