Most surfaces that are not frequently trafficked eventually develop colonies of mosses, lichens, fungi and algae over time. Again, prevention is better than cure, and regular aggressive brushing with a stiff-bristled broom and/or application of a general purpose weed killer such as sodium chlorate 2 or 3 times per year will keep colonization to a minimum, but can never completely prevent it.

Proprietary fungicidal washes are available from Garden Centers and these usually need to be applied during dry weather, allowing a few days following application for the fungi to be killed and dried in the sun, before removal by simple brushing.

Heavily affected areas are best scraped clean with a shovel or a garden hoe and the detritus removed. A stiff brush will remove the residual loose material and then the pavement can be washed down, sloshing the area with bucketfuls of water, spraying with a hose or, for best effect, cleaning with a power washer. Detergents added to the water can help, and, it has been claimed, addition of Jeyes Fluid will deter the vegetation from returning for a limited period.