Black mold is a fungi that has a green and black color. It thrives in areas that are damp, shaded and have moderate temperatures. Also known as Strachybotrys atra, black mold can grow on just about anything, including concrete. Keep the concrete dry to prevent black mold from forming in the first place. The best way to kill black mold is to attack in in its early stages with a mixture of water and chlorine beach.
Place a hose on its most powerful setting to clean off the concrete. Hose off as much black mold as you can. Wet the area with a sponge if concrete is inside.
Scrape off any remaining black mold with a spatula.
Mix a solution of chlorine bleach, detergent and water. Mix one cup of bleach and half cup of detergent for each gallon of water.
Apply the solution to the concrete with sponge or brush. Scrub as hard as possible to remove the black mold's roots.
Rinse off the concrete.
Scrub the concrete and rinse again if black mold persists.
Keep concrete as dry as possible. Remove (or cut back) tree limbs or shrubs that are blocking the sun. Dry with a fan if concrete is inside.
Try a power washer on commercial mold-killing product for particularly stubborn black mold growth.