10' x 3' wide, (tissue culture). Originating from northern Mexico, 'Sapphire Skies' is a stunning blue-leaved selection of the species introduced by Sean Hogan of Cistus Nursery in WA. Its flexible, non-threatening "jade blue" leaves are extremely showy as are the huge spikes of ivory flowers borne by the mature plants. A vigorous plant, 'Sapphire Skies' is a trunk forming Yucca reaching 3 to 4 ft. in 7 to 8 years, maturing at 10' or more. Sites with full sun and well drained non-clay soils provide the best growing conditions. Provide extra cold protection in zones 5-6 for the first couple of winters. Zones 5b (-10° to -15° F) - 9.