I have 2 of the regular planifolia covered in buds, some are flowering and I have beans. These plants are well in excess of 30 feet. From my experience success starts with superior cuttings . After that find a place that it likes, don't let it get too dry, and feed it. Mine are growing in large pots of leaf mold,sticks,some shredded spaghnum. I fertilize regularly with composted cow manure and micros.