Where do you live and how close to the house are you planting??? David

8B in coastal Virginia. The spot is to the left corner of the house. Planting location would be about 15ft away from the corner of the house (there is a 4.5ft ground gutter before you hit the house as well).

I cannot speak to specifics I leave that to others ... the distance is fine...you should be able to let it grow w/o trimming for many years ... The Bloodgood will give you more color the griseum is a nice green maple with winter bark interest ( defoliation)...if your corner gets alot of sun in that zone you will get leaf burn on your BG and in that case the grisioum may be better ( if Griseum's do good in your area I am NOT sure others will know) . I do think even with planting a bigger more exopensive tree you are looking at MANY years to get anywhere near that height and I seriously doubt either will get that wide in your lifetime ...but as I said others from your area may differ on this and their advise may be more apropos..David

Grisuem and Bloodgood in my zone in sun do fine once established. Bloodgood may leaf scorch in the first year or two, but once its established and if on an irrigation system - it generally won't scorch. It will however turn a bit more green/bronze but not quite scorched.

This particular location has afternoon sun but almost no sun in the morning as the house shades it. The preference for these two would be morning sun, but I do know that they can handle afternoon sun if watered well. Eventhough they are both very different in looks, I'm ok with either in that location. More interested in trying to get to about 20+' in height in some amount of time. I'd really like to put a beech purporea tri-color there, but that definitely won't take the full sun in my zone and that probably grows just as slow.

I'm curious as to how fast Griseum and Bloodgood grows if pruned for vertical growth rather just let to grow wide. I have a griseum that was planted last year and it put on close to 2ft (from 6 t 8ft) and caliper went from 1.5 to 2.5in. It was kind of shocking to me as I was figuring 6in to 1ft at most and minimal caliper growth. I don't know how long it will sustain this type of growth, but thicker caliper is usually a very good sign in trees. Pruning for vertical growth seems to help a lot of trees grow vertical (especially bloodgood, crape myrtles, prunus species, etc ). I know if you let Bloodgood has its way, it'll be 6ft in 5 years, but if you stake and prune it to go vertical, it can easily reach 12ft in 5 years. the question is what does it look like after 12ft ? Too many bloodgoods(and griseum) don't have vertical leaders. .

So, if anybody has any data on how fast(or slow) their bloodgood or griseum, it would be greatly appreciated.

How fast a tree grows is due in large part to the growing conditions - the more well-suited the growing conditions, the faster the growth rate, within reason. If you are located in an area that suits these trees and provide optimum growing conditions, 20-25 years is not out of line for them to achieve a listed mature height. Both trees can put on some pretty rapid growth when young and slow as they age. My own griseum, a seedling from a 1 gallon can, is now 10' tall after about the same number of years. But conditions for all Asian maples are pretty much ideal here and my 12 y.o. 'Sango Kaku' is approximately 2/3 of its suggested mature size and spread.

Personally, I would not opt to either prune or fertilize for fast vertical growth. IMO, excessive pruning negates the natural habit of the these maples, which is a very large part of their attractiveness. They are NOT single leader trees. And excessive fertilizing is never a recommended approach as it can lead to too rapid and lush growth susceptible to weather damage and insect and pest problems. If you want size quickly, buy 'em big to begin with.

My griseum has been growing slower and less vigorously than my red-leaved Japanese maples of similar size. Yet Bloodgood (and the multitude of "maybe Bloodbloods" that are sold as the real thing) are indeed pretty -- but they are also terribly common. The griseum on the other hand remains a relatively rare and unusual tree of great beauty. Much is said of its signature exfoliating bark. Less often talked about is its foliage -- interesting at any time of the year and spectacular in the fall. In New England griseum and trifolium are among the very few trees able to surpass out native rubrum in regards to autumnal color and I suspect this is probably the case elsewhere in North America as well. Given the choice of planting an estabished sapling of griseum or Bloodgood, I would hasten to chose the former.

I think you might be right in choosing larger trees. I do want the tree to hit the roofline or a bit above to look right for the scale we're looking for in that area. Obviously this lifetime would be good. . . What I have in availability in larger trees is decent. I've personally got a Griseum that has two leaders up top about 9ft tall that I'd prefer not to move. The nursery has a single leader Griseum that is about 8ft tall and 2" in caliper. Bloodgood availability is quite good as I can get 10(2.5"), 12(4in) 15ft(6in) caliper trees. The 15 footer is pretty nice and pretty costly, but something to consider.

My question is if starting with a 9ft Griseum or a 12 to 15ft Bloodgood, what do you think I'll have in 5 to 10 years ? Does anyone have a Acer Griseum or Acer Bloodgood in the 20+ft range that they planted ? It seems like everyone's that I know is in the 10-15ft range. What I don't want is to plant a tree in that range that stops about there. These are both slow growing, but we'd want something that could hit in that 20-25ft range over a reasonable amount of time.