We just transplanted large (4-ft. tall) crape myrtles from the black clay soil of San Antonio to the sandy loam of south Texas. They sprouted immediately and one is blooming, but the edges of all the leaves are browning, drying out and one tree lost all its leaves. I think I am overwatering, as this sandy soil holds water like a sponge. Should I wait till soil dries out before re-watering? Also, we are in an area of constant, hot winds. Could this be windburn? HELP!