Treat grass-stained garments with a prewash stain remover. Then launder garments as usual, using liquid chlorine bleach if it is safe for the fabric. If chlorine bleach isn't recommended, use oxygen bleach instead.
The sooner you pretreat and launder the grass-stained clothes, the better your results will be, If a stain isn't removed in washing, don't dry it. Dryer heat will set the stain. Instead, try soaking the stain in an enzyme prewash product or a solution of liquid laundry detergent and water. Then, launder again.
