American Holly Tree 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 30 to 50 feet tall with a 15 to 30 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 9. Expect visits from pollinators, butterflies, and birds throughout the growing season.