HELP!!!! I recently put moss killer granuels on my front lawn...not paying attention, or course, to where the granuels were flying. WELL, the next time it rained?? I have these orange spots EVERYWHERE on my driveway and sidewalk. I've tried my pressure washer, but it doesn't work...any ideas? Thanks! Bryan from Washington.
most moss killers for lawns are ferrous sulphate (Iron and sulphur) they will stain most surfaces when they get wet and oxidize. I dont know of a cure beyond scrubbing and washing the area well.
Try pressure washing it. Even then, if the surface is concrete, you are unlikely to get rid of all of the stand. Do not use any chemicals, like bleach, on the stain, as there is a risk that you may "fix" the stain and make it more "permanent".
Muratic acid is a last resort, vinegar or lemon juice works well with a good scrubbing, but usually only within the first few days of staining concete, after that it really sets in.
I found a solution to the pesky orange “Moss-Out” stains on concrete, aggregate driveway, and stucco. The gallon jug of “acidic toilet bowl cleaner” from Home Depot, viscous and dark blue, is basically weak muriatic acid with soap added. Apply to exterior hard surfaces at full strength with a long-handle soft bristle brush. Scrub-in thoroughly. Wait four minutes maximum—or sooner if the foaming surface starts turning purple—and then rinse heavily with normal hose. Voila!
