Fertilizer that accidentally lands on walkway and patio pavers may leave behind stains. Orange stains are most common. These are formed from iron in the fertilizer or weed killer reacting with moisture to form rust. Occasionally, white stains also appear from salts in the fertilizer. Pavers are usually made of concrete mixed with sand or pebbles, so power washing is not an option, as it may break the pavers apart. Removing the fertilizer stains without damaging the pavers is usually possible.
Pour fresh lemon juice onto the stained area. Allow it to set on the stain for five minutes.
Scrub the stain thoroughly with a nylon bristle brush. Allow it to set for an additional five minutes then rinse off with clear water. Repeat until the stain is gone.
Purchase a commercial rust remover from a home improvement store to remove any remaining stains. Look for one that uses oxalic acid as a main ingredient.
Apply the rust remover following label instructions. Wear gloves and eye protection when using these products.
Flip the stained pavers over if stain removal does not work. Loosen any soil between the pavers with a flat spade or chisel then lever the spade under them to lift. The back side of the pavers often just requires the dirt to be rinsed off to look like new.