Using scissors or a knife to make little cuts(wounds) in stem. Remove some leaves. Be sure to do this in approx. the center of the stem, leaving lots of stem to the mother and to the end of the stem itself.
Bury the 'wounded' part of the stem. Always leaving the stem attached to the mother plant!
Add Mulch. It helps! (but not a must).
Place a stone on top of buried section. This helps hold stem under ground.
Water!!!!!!! Water often during waiting time.
WAITING TIME!!!..How Long?? A couple months would be ideal!
Look!! New Growth!! A good sign of new roots!!
Loosen soil with shovel. Try not to cut roots with shovel!
Cut a generous piece of new growth (roots) from the mother plant!
Dig a hole in a new location or fill a pot with soil! Place root system in hole(or pot).
Cover your 'new growth' ('New plant') with soil.
Keep watered to help plant take to new home!!
I find this to be the easiest way to get new trumpet vine plants.