Castle Spire® Blue Holly makes a beautiful addition to the landscape with year-round visual interest. Flowers appear in late spring, adding welcome seasonal color to the landscape. At maturity it reaches 6 to 10 feet tall with a 4 to 5 feet spread, so give it room to develop its full canopy. Plant in full sun for the best results. It thrives in zones 5 through 7. Expect visits from pollinators, butterflies, and birds throughout the growing season.