Dirt and debris from vegetation can build up on your fence over time. A thorough cleaning every year should help it look brand new again. You can employ a number of different methods of cleaning to figure out which works best for your fence. Using a power washer or your garden hose may help take off some of the dirt. Stains from mildew and vegetation will probably require a finer touch; vinegar and water are usually sufficient for dealing with stubborn stains. Some marks and stains may require specialized care to remove. Black marks from rubber, for example, can often be removed with a pencil eraser.