Chaste Tree

Vitex agnus-castus

“Blue-purple spikes in the dead of summer when nothing else is blooming.”

Medieval monks used it to suppress desire — hence the name. In your yard it'll do the opposite: long, fragrant lavender-blue flower spikes emerge in mid-summer heat when most trees have given up producing anything interesting. Butterflies and bees lose their composure over it. Grows as a multi-trunk small tree in Zone 7–9, dies back to the ground in Zone 6 and returns stronger. One of the best blue-flowering trees for the South and West.