I have a hillside with a healthy growth of common vetch (Crown vetch, I believe - don't know the botanical name) and I would like a lot more of this on that hillside - too hard to mow ! Can I do this with stem cuttings or does it have to be done with root cuttings ? I didn't notice if this plant set seed last year. If it does, is this a good way to go ? TIA. Sonnie OH zone 5