Considering the lack of blue-flowering, summer-blooming trees and shrubs, we’re surprised that more chaste trees aren’t planted. Slender, 12″ long flower spikes cover this deciduous shrub from early to late summer. Loved by hummingbirds and butterflies. Grows quickly to reach 15-20′ tall. Thrives in hot, dry, sunny locations and tolerates high humidity and drought. One of the most spectacular flowering trees for the South. Zones 6-9.