Tree sap will stick to just about anything, from hair to skin to cars to clothes. Tempting as it may be to simply toss the soiled clothes in the washer, laundering clothes that have tree sap still attached can result in permanent staining. Prior to washing, the sap must be removed. With nubby fabrics, such as fleece, this can be a bit of a challenge.
Cover a hard, level surface, such as a table or countertop, with an old towel. Lay the jacket flat across the towel, with the affected portion of the garment facing up. Place several paper towels inside the jacket, directly beneath the area covered by sap. This will prevent the pitch from seeping through the fleece.
Soak a cotton ball with isopropyl alcohol, and then press the saturated cotton against the sap. Squeeze the cotton ball gently, encouraging the dispersion of a small amount of alcohol directly onto the sap.
Gently scrub the treated area with an old toothbrush, loosening the sap from the fibers of the fleece. Wipe the sap away with a paper towel.
Pour 1/4 cup powdered laundry detergent into a small bowl. Add enough water to make a paste. Spread the paste thickly over the area where the sap was. Allow the detergent to sit for 10 to 15 minutes, then wash the jacket as normal.
Inspect the jacket after washing, and if any trace of sap remains or any discoloration has occurred, repeat the entire process. Do not put the jacket into the dryer until all the sap has been successfully removed, as the heat from the dryer will permanently fix the stains into the fabric, making them almost impossible to eliminate.