How to remove algae from paths

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After a particularly wet spell of weather, you may notice an unattractive green, powdery film or deposit developing on the stone or wood surfaces in your garden. This slimy coating could be algae. Once algae starts to collect on a path, it may render it slippery when wet.

In areas with large trees or next to ponds and puddles, you will notice that shade and moisture create an environment where algae thrives, especially in the late winter and spring.

Mix a solution of bleach and warm water. Use 3/4 of a cup of bleach for each 4.5 litres of water. Household chlorine bleach will do the job. If you have concerns about the environment, use oxygen bleach instead. Avoid bleaches that gel or become thick since it tends to sit in one spot. This will make it harder to give the surface an even cleaning.

Pour the solution onto the path and let it sit. After about five minutes use a broom or scrubbing brush with thick, hard bristles to work the solution into the path's surface. If you have a large path, work in sections so that you can control the amount of bleach on the surface.

Rinse the bleach solution from the path with water from a garden hose or pressure washer.

Repeat the process two or three times to remove all the algae.