Blue yucca, a trunk-forming species with minimal branching near the top. Its distinctive, powder blue leaves are rigid, with yellow margins. These blue leaves have a sharp spine at the tip. In the late spring the blue foliage is complemented by a showy stalk of white flowers. For best growth, provide supplemental water in the summer, and plant in well-drained soils. Blue yucca can be planted in full sun or very light filtered shade.