LICHENS on VINYL FENCE: HELP! Having always wanted a white picket fence with roses growing over, I was thrilled to have my husband drive all the way to Grants Pass to buy it for me. I call it my folly. In England, on the grand estates, you often see a Greek temple or a Japanese tea house in the distance---though the owners are neither Greek nor Japanese. It is a folly: there for no other reason than to please the eye! That is my little white picket fence: it keeps nothing out, and fences nothing in. But now, after a few years, it has pale green lichens growing on it. That commercial product, "Wet and Forget" had no effect on these lichens. Vinegar was no help. A dilute bleach solution had little effect. CAN ANYONE HELP? ? ? Please?