They have similar looking bark, but what are the differences?
Being a Sec. Macrantha maple the first will have thicker twigs, fewer branches, striped bark and bigger, less divided leaves. If you want the elegance of Japanese maple, you will prefer the latter cultivar. I've had one a short time, I noticed lately the tips of last year's growth are dead, somewhat marring the effect. When you choose a grafted Japanese maple you may often experience disease issues at some point. Bacterial blight, for instance is sufficiently common that at least one Oregon grower talks on their web site about how they bring their crops of Japanese maples into the overwintering houses early in fall, in order to protect them from the damp and cool conditions that favor blight infestation at that time of the year.
I'm thinking mine didn't harden off completely last year and lost the tips to frost, I did notice it was still growing late in the season. Not that I am seeing signs of it on mine now, but such damage can serve as entry points to bacterial blight later. A tall, long-established magnolia tree at the Seattle arboretum was lost to what was very likely bacterial blight after its tips got frosted during an early cold spell one autumn.
This post was edited by bboy on Sun, Feb 24, 13 at 14:59
I've only seen the A. p. 'Bihou' grafted. Is that for ease and speed of propagation or because it won't grow from cuttings?
I noticed the A. p. Bihou at the garden show were very upright. Is that it's growing habit or the result of growing conditions?