How you train a Japanese maple is pretty much up to you. Yes, you can train one of those lateral branches (not 'trunks') more vertically by staking. And I would NOT remove the other - it balances out the plant.

The habit of 'Red Dragon' is that of an umbrella-shaped little tree. In time, the lateral branching will spread and cascade over and additional branching following the same growth pattern will emerge from them, forming a dense, weeping canopy.

Personally, I dislike staking weeping dissectums and remove the stake as soon as I get them so they can start assuming their natural growth habit. But many folks DO stake them to get a taller plant.

This what the typical growth habit of 'Red Dragon' looks like.

ps. This forum is very quiet. You will get more responses to your maple questions on the Maples Forum. It's quite active and many JM folks hang out there.

Thank yoy very much garden gal

I have a similar JM as in the photo. What if the portion that you want to stake doesn't really bend straight up to be staked? I feel like if I made that portion vertical it would just snap the branch.

Staking can only be done while the branch wood is still young and flexible. Sometimes, precisely vertical is difficult to achieve - this is after all a weeping tree and is not inclined to grow vertically - but even encouraging the leading stem in a more upward growth habit will help to increase height. If you do this with each new primary branch as it begins to extend from the framework, you will eventually have a taller but layered specimen.

I see. I have another question. Let's say that the JM in the photo was left as is. Would it ever get taller on its own? Or does the main trunk just get thicker, but not taller? In other words, does the entire tree "scale up" as it grows up, or is it pretty much just horizontal growth if left alone. Hope you understand that question, lol.. Thanks.

Yes, the tree will get taller on its own without staking..........but not hugely so. New branches will develop to increase the height of the canopy but the trunk won't elongate. It is what it is :-) You could expect to see maybe 8-12" of increased height over the lifetime of the tree with no further staking.

These types of Japanese maples - weeping dissectums - are most often grown and sold as small, umbrella shaped accent 'shrubs'. These are low graft trees, with the weeping portion grafted on to a short understock trunk. Since the weeping portion will naturally grow out but not up, the ultimate height is pretty much predetermined. High graft dissectums just have a taller portion of rootstock trunk they are grafted to, so a taller tree from the outset but not hugely so. And either can be staked and the topmost branches trained more vertically upward to achieve a taller, layered looking tree. So instead of a short little mushroom or umbrella looking tree, you will get one that is a series of 'flounces' or weeping layers like a woman's petticoat. But there is a limit as to how tall you can train these. The weight of the branches are a limiting factor as the tree matures and heavy branching on a too tall tree (for the habit) could cause tearing as the upper 'trunk' (or leader) from which they are growing is unable to support their weight.

Hi, you can also check out this short video from Whitman farms owned by Lucile Whitman. She demonstrated how to train a weeping JM to grow taller.

http://www.whitmanfarms.com/blog/how-to-train-a-weeping-tree/