Ok, this is a picture of a polar bear in a snowstorm! NOT! This is the kind of board you want to replace those rotten trim boards on the peak of your roof. WILL NOT ROT. DO NOT NEED PAINTING. CAN SIT IN STANDING WATER. Yes they are more expensive but only need to be installed once by brave people whose ancestors fought off flying monkeys. They are made of PVC, vinyl, yes, plastic. Click on image for link.
This is another option: Boral Truexterior trim boards. They handle like wood but are closer to stone. Ends don't need sealing, approved for ground contact. Have one smooth side and a wood grain texture on the other. Click on image for link.