Lack of sunlight and excess moisture contribute to mold growth on walkways. Whether you have concrete, brick or flagstone walkways, mold can leave unsightly green, brown or black stains on the surface. If left on the walkways for too long, mold can erode the porous stone and destroy your walkways. Harsh cleaners, such as chlorine bleach, are harmful to plants and animals. Oxygen bleach kills mold and brightens stone without harming wildlife or vegetation.
Fill a bucket with 2 gallons of hot water. Add 2 cups of powdered oxygen bleach and allow it to dissolve for five minutes. Stir the mixture gently with a wooden spoon.
Pour the oxygen bleach solution over the moldy walkways. Allow it to sit for 20 minutes to clean the walkways and kill any mold.
Scrub the walkways lightly with a push broom.
Spray the walkways with a garden hose to rinse.
Push any standing water from the walkways with the broom.