I got an AP Waterfall this spring that is about 12 inches high and (for the sale price I paid) I think it has a fairly nice whorl of branches surrounding the little trunk. My question is will the stem/trunk eventually grow higher? I'm not clear if the branches are grafted onto dwarf stock or if it naturally grows this way from seed. There is a joint about 4 inches up the plant suggesting the dwarf stock option is more likely. I was drawn to the beauty of this cultivar after having seen several 4 - 5 foot tall specimens in nurseries. I'm hoping this little one I purchased has that potential. I read the archived posts relating to Waterfall but they don't seem to talk about this question. Thanks.