Submitted by Jason Reeves, UT Gardens, Jackson
In the 1960s, a cross was made between two U.S. native trees in the Bignoniacea family, northern catalpa (Catalpa bignoniodes) and desert willow (Chilopsis linearis). The combination of large growing, big leafed northern catalpa, (hardy to zone 4) and the much smaller growing, narrow-leafed desert willow (hardy zone 7) led to a small tree that proved to be hardy to zone 6 and was called x Chitalpa. Chitalpa grew vigorously in youth with a shrubby, loose, open habit, and an abundance of flowers on new growth during the summer. The foliage was medium in size but highly susceptible to mildew, and overall, the hybrid did not measure up to other deciduous flowering shrubs and never became mainstream. For more on this; CLICK HERE