1, the first harvest of alfalfa is at the beginning of flowering Alfalfa's flowering period is from May to July every year, and it enters the early flowering period in early May. This is when the first harvest is needed, because the crude protein content in alfalfa is highest at this time.2, the last harvest of alfalfa is one month before the first frost. Alfalfa can be harvested three times a year, and the third harvest should be one month before the first frost. If you harvest after this time, not only will the quality of the forage be lower, but the nutrient content will also be low.3, pay attention to the stubble height when harvesting alfalfa. When harvesting alfalfa for the first time, leave five centimeters of stubble, which is conducive to the growth of alfalfa again. When harvesting for the last time, leave about seven centimeters of stubble, which is conducive to safe overwintering.