Copiapoa cinerea

Endemic to a zone where measurable rainfall is virtually non-existent, this plant survives entirely on the cool, moisture-laden camanchaca fogs rolling off the Pacific Ocean, which are captured by its woolly apex and channeled down its heavily waxed ribs. In a coastal Zone 10b environment, it thrives outdoors beneath the protective diffusion of shade cloth and a polycarbonate roof, which shields its pristine white body from scorching while blocking out cold winter rains. It demands an uncompromisingly fast-draining mineral substrate—such as a gritty blend of pumice, decomposed granite, calcined clay, and a touch of cactus soil. Housed in a breathable raw cement pot, it should be watered with extreme discipline only during warm, breezy weather, enforcing a strict, completely dry dormancy throughout the winter to prevent fatal rot.