Make it grow denser and branch out more by giving it good care, encouraging it to grow. Do not head it back. If it's not growing a couple feet per year, like mine did, then it is not up to potential for this area. (2 feet per year is still slow for a tree, actually, so this was not a radical departure from expectations for this species). If mulching, nutrient levels and irrigation are surely adequate then maybe exposure is not. These definitely grow skinny if shaded too much or crowded, as do many other trees.

Wow, should it be growing a couple feet per year? That seems like an awful lot flow a "slow growing" tree; I know mine has not put on that kind of growth, and I haven't noticed any new branching, except maybe some of the really small, twiggy bits. The caliper has increased since I purchased it, though. This tree gets full southern exposure and is not crowded at all. I have it mulched, although I'm sure I can improve on that. I have not fertilized though (I don't really fertilize any of my trees as I have found that hasn't really helped in the past). Are there any other suggestions? Thanks bboy!

IME, time is a factor. My own griseum has a form similar to yours with a similar height and trunk caliper also. But it has filled out quite a bit from its original, more seeedling like appearance when it was planted about 5 years ago. And I expect it to continue to do so until it develops a more typical maple-like canopy. I would also consider a 2' per year growth rate to be pretty optimistic for this species as well.

I'd hold off on the pruning and let time and nature take their course. Unless the tree is showing signs of nutrient deficiency, fertilizing is most likely unnecessary (and should be done only after a soil test indicates what is lacking), but mulching lightly with compost won't hurt a bit.

If it's hardly growing at all something is clearly wrong, almost certainly needs to be addressed before a marked improvement can be expected. Are you keeping it moist in summer? Many people here are unaware of the significance of our dry summer to ornamental plantings. Partly this is a factor of soil conditions, some sites will stay moist through summer but probably most places that "perk" need some irrigation to support normal growth of plants from monsoon climates (such as paperbark maple).

Another common problem that perhaps most are unaware of is Armillaria. If this is working on a plant top growth may be poor.

Thanks for the extra responses. My tree looks quite healthy, and upon closer inspection, the side branches do look a bit fuller than I initially thought. Perhaps I am simply being impatient, not knowing exactly what "slow-growing" means for this particular species. I will have to be more diligent about keeping it well watered in the summers, and about adding compost as mulch. Bboy, what is Armillaria?

I think this one grows *really* slow, I'd guess a foot a year would be pretty decent.

Elevated crown due to pruning and training by grower, of course.

Dax,

thanks so much for posting the pic. My crown isn't quite that elevated- I'd say the branches begin about 4 ft. from the ground. This certainly gives me hope and makes me feel better! :)

You've given this 12ft maple enought time to show itself; it's no longer a seedling in a 3" pot. It's time for some tough love, time for some intervention

note: this process will initially make your tree look really hideous, but next year it will look great.

I would
- chop the 1/3 of the leader
- trim back all the new growth to one segment (node) and remove dead branches.
- if the upward pointing branches is movable wire it down to a desirable angle
- if not movable chop back to the nearest segment (node) before it started growing upwards.

When the sap starts emerges from it's winter hibernation, it will realize it has no where to go and just get fat and spread it's papery bark. Like blowing a latex glove. This might cause some sucker growth from it's normal two buds per node, so leave one or two and rub off the rest.

regards, Cesar Ramos

would any of you folks have a nursery you'd recommend that ships acer griseum ?