Also, my mom has had some success with keeping dormant roots alive through the winter. She cuts plant off about three inches above the soil, and buries the stump under a mound of leaf mulch about two feet thick. In the spring she uncovers stump, gives it a good dose of ferts and new branches come out from sides of the stump. Problem is this really only works outdoors, and roots still may die during winter. You can tell if roots died with a glance when you uncover in the spring. Stump will be completely brown ( if alive stump below amputation will be green ) and a tug will confirm that roots are no longer viable in the soil. Still, if you grow outdoors and have a good performing plant it's worth a shot to have it grow back the next year.
