Alfalfa is rich in protein, vitamins, and minerals and has the ability to fix nitrogen and improve soil structure as it disintegrates. Alfalfa yields an alcohol, triacontanol, which is a growth stimulant that produces basal breaks. Do not apply alfalfa as a heavy mulch on your roses. You only need to use 1 cup around each large rose bush, and less for smaller bushes. Use about three times a year.