Damp or forgotten blankets can easily grow mould. Occasionally, running the blanket through the washing machine immediately after you discover the mould is enough to remove the marks, but often the stain is discovered after some time has elapsed. Sunlight and fresh air help to kill mould spores, but often you need stronger means to completely remove mould from blankets.
Take your mould-stained blanket outside. Mold spores spread easily and multiply quickly, so you want to keep as many of them out of your home as possible.
Brush away as much of the dried surface mould as possible with a stiff-bristled brush.
Spread the blanket in the sun for several hours. If the mould stains are fresh, this may be enough to kill the mould and allow you to brush away any remaining stain. Older or large stains will require more care.
Mix 3 parts baking soda and 2 parts white vinegar into a paste. Rub the baking soda paste into the mould stain and allow the blanket to sit for at least 30 minutes.
Wash the blanket according to its label instructions. Do not place the blanket in the dryer. Instead, take it outside and examine it carefully to see if any mould stains remain. If stains are still present, apply a paste of lemon juice and salt to the stains. Allow the blanket to dry in a sunny location before examining it again to see if the mould is removed.
Rinse the blanket in your washing machine and allow the blanket to dry completely outside in the sun.
If you smell a mildewy or musty smell before you actually see mould stains, wash the blanket and allow it to dry in a sunny spot.