Blue Yucca is another trunk-forming yucca, and grows to 12 feet tall, with minimal branching near the top. Its distinctive, powder blue leaves are fairly rigid, with yellow margins. These blue leaves are about 3 feet long by 1 inch wide, and have a nasty spine at the tip. In the summer the blue foliage is complemented by a showy 5 to 6 foot 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, and is
hardy to 5º F. USDA Zone 7.
Like all Yuccas makes a wonderful house plant too.
Sow spring in a greenhouse. Pre-soaking the seed for 24 hours in warm water may reduce the germination time. It usually germinates within 1 - 12 months if kept at a temperature of 80�F. Prick out the seedlings into individual pots when they are large enough to handle and grow them on in the greenhouse or cold frame for at least their first two winters. Plant them out into their permanent positions in early summer and consider giving them some winter protection for at least their first winter outdoors..