• The first thing you must do when treating grass stains is to remember not to wash the stained garment with hot water, which will cause the stain to become permanent. Wait until the stain is completely removed first, using cold water in combination with the cleaning solution of your choice. Grass stains are commonly regarded as difficult to remove, but there are a few common household chemicals and detergents that you can use to remove them without harming or discoloring the garment.
  
  

Laundry Detergent

• Laundry detergent, if properly applied, can be all you need to remove grass stains from a garment. Rather than run a normal wash cycle, soak the garment in cold water, and then apply the liquid or powder detergent. Scrub the detergent into the garment, let it sit for 15 to 20 minutes. Wash the garment in a normal cold-water cycle.
  
  

Hydrogen Peroxide with Bleach

• If you have grass stains on white garments, try using a solution of hydrogen peroxide, bleach and water. Mix equal parts bleach and hydrogen peroxide with 3 parts cold water. Soak the garment in the solution for an hour, rinse and run the garment through a cold-water wash cycle with detergent.
  
  

Vinegar

• Vinegar can be used to remove grass stains when used in a solution. Create a solution using 1 tablespoon of white distilled vinegar and 1 cup of either ammonia or warm water. Pour the solution directly onto the stain and rub it in. Let the garment soak in the solution for 15 minutes before running it through a cold-water cycle with detergent.
  
  

Isopropyl Alcohol

• Rubbing alcohol can be surprisingly effective in removing grass stains. Soak a clean sponge in 91 percent isopropyl alcohol and let it dry. Wet the sponge with cold water and pour 1 tablespoon of liquid or powder laundry detergent onto the sponge. Scrub the stain with the sponge, rinse under cold water and run the garment through a cold-water wash cycle.