In MY experience..THAT vine is a weed and is so VERY hard to kill. I made the mistake of planting it and ended up with it in my lawn and in my neighbors lawn! Then it got attacked by some kind of catapillar and it was gone. But I am still pulling up sprouting roots nearly 2 years later. It is thriving in a neighbors year! So..I think if you get a few roots on a cutting and plant it as deep, in a small pot,with good light soil...it should root and take off ,fast!

Digging up the daughter plants are the quickest and easiest way to propagate incarnata--easier than seed, even. Repot the root cutting and it should do fine.