Crape Myrtle is a summer flowering favorite in southern gardens and landscapes. Because of their heat tolerance, these flowering trees bloom profusely even during the most intense, humid summer weather. Visit our Flowering Trees for more ideas to brighten your landscape. Flowering Shrubs are often used where space is limited and trees cannot be planted. In zones 5 and 6, crepe myrtles often die back to the ground in winter to re-emerge in spring.... As a result, a Crape Myrtle Tree that is listed as maturing to a 20 to 30' tree in warmer climates may remain as 5 to 10 foot tall shrubs or small flowering trees in the cooler growing zones. But you still get to enjoy its fantastic flower clusters!