What is the process for crossing a chilopsis and catalpa?

I live in Southern New Mexico and have planted 4 Chitalpa Tashkentensis. I would like to know if they are crossed via grafting or some other method. Also, I heard that cuttings germinate easily. Is this true and what process is most recommended?

I wouldn`t know but I will tell you to go ahead and try stuff. :)

I have not been successful in crossing catalpa and chitalpa ,which already is a hybred of catalpa and chilopsis. Chitalpa grafts very readily on catalpa.Chilopsis grafts but not very vigorously. As to rooting cuttings, have at it! I would like to see good selections of chilopsis crossed to a selected catalpa from northern Illinois. That should result in an improved chitalpa