Cedar is a premium greenhouse frame material because it is naturally resistant to rot, decay, and insects. It is structurally strong and stable, yet lighter than many hardwoods. Unlike aluminum, cedar does not conduct heat or cold as quickly, which can slightly reduce temperature transfer through the frame. Over time, it weathers gracefully and maintains its structural integrity for decades when properly maintained. For buyers who want a durable, natural, and architecturally warm frame material, cedar is a premium choice.