Wash the blanket in cold water. Use regular laundry detergent and the gentle cycle. During the rinse phase of the wash, add about ½ cup of vinegar to help prevent shedding and pour in one capful of fabric softener. Allow the wash cycle to finish.
Hang the blanket outdoors to dry. This will not only help prevent some of the fibers from shedding, but it will also cause loose fibers in the blanket to float away in the breeze.
Rub an adhesive lint roller all over both sides of the blanket to remove additional loose fibers to prevent shedding.
Wash the blanket about once a week until it stops shedding. Most blankets should stop shedding after two or three washes.