Assess and Pre-Treat the Stain

• Inspect the stain: Grass stains can be stubborn, so it’s important to assess how long the stain has set in your denim. Fresh stains are easier to treat than older, set-in ones.
• Pre-treat: Gently scrape off any dried residue with a dull edge like a spoon. Then, apply a small amount of liquid laundry detergent directly onto the affected area. Use a detergent that is known for lifting stains without harsh additives.
• Work it in: Rub the fabric together lightly to help the detergent penetrate the fibers. Avoid aggressive scrubbing, especially on denim, as it can weaken the fabric over time.

Let the Treatment Sit

• Wait a few minutes: Allow the detergent to work its magic on the grass stain. Let it sit for about 10-15 minutes. This dwelling period gives the detergent time to break down the stain-causing compounds.
• Keep an eye on the fabric: If you’re worried about potential discoloration, test the detergent on a hidden seam first.

Rinse and Soak

• Rinse: Rinse the treated area with cold water from the back of the stain. This helps push the stain out without driving it further into the fabric.
• Soak if needed: For persistent stains, soak your jeans in a basin of cold water mixed with a bit more detergent for around 30 minutes. Cold water is key—it prevents the stain from setting further.

Machine Wash with Caution

• Wash on a cool cycle: Once pre-treated and rinsed, wash your denim jeans according to the fabric care instructions. A cool cycle is recommended; high temperatures can complicate stain removal by setting the stain.
• Use a quality detergent: Choose a detergent known for its cleaning power. While tough on stains, avoid abrasive chemicals as denim is a durable fabric but benefits from gentle treatment.
• Double-check: Before tossing your jeans in the dryer, inspect the stain. If any trace remains, repeat the pre-treatment and washing process. The heat from the dryer can lock in any residual staining.

Final Tips and Considerations

• Patience is key: Grass stains may require a couple of treatments. Consistent care and gentle handling often lead to effective results.
• Avoid harsh chemicals: Stick to a trusted detergent and simple cleaning techniques. Over-complicating with extra chemicals isn’t necessary—denim's durable nature works well with basic care.
• Routine maintenance: Regular cleaning of your jeans not only removes stains but also helps maintain the fabric's overall appearance.