How to kill moss on patios

A patio can be an enjoyable outdoor feature. Moss spores may be present on your patio's surface. If your patio has excess moisture or doesn't receive enough sunlight, the spores may grow into a mossy mass. Not only may moss look unsightly, but it may also pose a safety hazard due to its slippery surface. Kill the moss on your patio to restore your patio's appearance and protect your family's safety.

Pour half a gallon of water and half a gallon of common household bleach into a plastic bucket. Add a cup of powdered washing powder. Mix thoroughly to dissolve the detergent.

Pour the bleach and detergent solution on your patio where you notice moss growth. Allow the solution to sit on the mossy growth for 30 minutes. The bleach will kill the moss and any residual moss spores. The detergent in the solution will help remove the actual moss from the patio surface and also helps loosen any stains caused by the moss.

Scrub the area with a mop or shop broom to remove the dead moss. Hose down the patio with fresh water to rinse away the bleach and detergent solution.

Spray the moss with a commercial moss killer spray as an alternative to using bleach and detergent. Example products include Safer Brand's Moss & Algae Killer or Bayer's 2-in-1 Moss & Algae Killer. This is a good option for homeowners who only need to spot treat limited amounts of moss growth. Spray on to the moss according to the instructions provided by the manufacturer, as chemical formulations and strengths typically vary.

Dry the patio thoroughly after cleaning it with the bleach solution or a commercial moss killer. Use rags or towels, or blow a fan over the patio surface. Allowing the patio to remain wet increases the chance of moss regrowth.


Rearrange patio furniture, and trim any nearby trees or shrubs, to increase the level of sunlight on your patio. Sunlight will discourage the growth of moss.

Things You'll Need

  • Gallon-size plastic bucket
  • Household bleach
  • Powdered washing powder
  • Mixing stick/spoon
  • Shop broom or mop
  • Hose
  • Commercial moss killer
  • Rags or towels
  • Fan
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About the Author

Joshua Duvauchelle is a certified personal trainer and health journalist, relationships expert and gardening specialist. His articles and advice have appeared in dozens of magazines, including exercise workouts in Shape, relationship guides for Alive and lifestyle tips for Lifehacker. In his spare time, he enjoys yoga and urban patio gardening.