Today I cut back easily 80% of a large 'Potato Mint' (Plectranthus species) that had sprawled over much of my northeast street flower bed before I apply Mills Magic Rose Mix organic fertilizer and give the bed a deep watering. I was disappointed that the very center of maybe 20 inches across is where the tubers seem to be growing. The cuttings will get composted. I have never grown this before so hope I enjoy the tubers. John