Insects such as flies are naturally drawn to vinyl siding because vinyl siding attracts build up of airborne sugar particles from nearby trees, plants and brush. Unlike brick or wood homes, the sugar particles (which may not be detectable to the human eye) stick to the vinyl siding, causing flies to gather.
Ensure that the length of your garden hose will reach the vinyl siding you wish to clean.
Turn on your water spigot to maximum output.
Using your garden hose with the spray attachment on, wash down your siding.
Cover the entire area of your siding. If you miss a portion of the siding, the flies will still continue to hover around the area you missed.
Let your vinyl siding air dry.
Repeat as often as needed. If your vinyl siding is near a flower garden or a large collection of trees or brush, you will probably need to give the area a weekly rinse.