Friday, November 11, 2011

Moss/Algae on sidewalks

After abundant rainfall, what to do about all the slippery growth on driveways and paths around the home. (often referred to as slimy blobs of olive green matter similar to what one would expect floating on a pond).
Living in the tropics, we are often plagued with unsightly and dangerous moss and algae growing on driveways and pathways around our homes.  When the rain stops, the green growth will dry up but will regenerate again with the next rain. 
There are many different products on the market to help you clean up the driveway.  Look at the active ingredients on the label; most products will contain bleach, copper, or soap. Be sure to follow the directions on the label.  Most are sprayed on, left for a while and then washed off with a hose – sometimes with the help of a shovel/scrapper.  Often times the buildup is so great that a power washer is needed. Bleach is often recommended at one cup per gallon of water. 
When using copper and bleach, there is always the potential for these products damaging desired plants either from the direct spray or from the solution entering the soil. Take caution when spraying near desirable plants. The damage is lessened in high rainfall areas through the leeching action of the rain.
Another option is to use one cup of vinegar per gallon of water; bleach is sometimes added to fortify the solution as vinegar alone may not always work.   An application of Roundup herbicide will kill the algae and moss, but the plant residue still needs to be scrapped off.