Left untreated, cedar will weather to a beautiful gray. Painted or stained cedar does offer better long-term weather resistance, but cedar is naturally wind, hail and rain resistant. Western red cedar will last longer and age better than many man-made materials. Correct installation of cedar over proper substrates are a must. Consult a local professional for the appropriate backing materials for your area. Use stainless steel or hot-dipped galvanized nails of the appropriate length. Do not use electroplated, galvanized or unfinished nails. They will rust, and stain the siding or worse, they can weaken the siding and lead to expensive repairs. Once a year clean your siding by using a stiff broom or brush. Like any thing of value, caring for your cedar will keep it looking new for years to come and even though cedar is tough, with care it very well may last you a lifetime.