A question about trunk growth. Acer Rubrum

I know these are basic questions but I am looking for a little guidance and support. I have three of these trees started from seeds one year old (in spring) and I am curious as to when I should start controlling height and if I do will that stunt the trunk girth growth?

Not for a long time as you want robust growth for some years to develop trunk girth. It will be worth your while to read some good books (there's a recent thread on IBC about the topic) and you may wish to read some of Brent's articles... http://www.evergreengardenworks.com/articles.htm

Thanks John. I have read many things stating it's never too early to start training but I could never find a straight answer to the question "If I top off the tree will the trunk stop growing in girth?"

Hello Philip. Girth will increase with any growth, be it top or side. Girth can be controlled in different ways though. If yuo want a tall slender tree then you grow the top more, reduce the height to a branch, wire it as a new top and let it grow again. Repeat this process until you reach the required height/ taper. If you want a short stocky tree, then you keep some low branches and let them extend for a long time, increasing the girth but keeping more control of the top this time by cutting back hard and low. This is best done with the tree in the ground, for quick results.

With Acer Rubrum you should be able to follow the same basic techniques as tridents. For a very basic "how to" you may try to get your hands on a copy of Peter Adams book "Bonsai with Japanese Maples"......although strangely there is a trident on the dust jacket. Much of the information he covers uses seedling material.

I believe Vaughn Banting created a really nice forest using acer rubrum. Maybe good inspiration for you to find the progression online. That planting is the only really nice rubrum bonsai I think I've seen around.

Good luck!
Neil

You first need to decide what you are shooting for -- how large a tree, what style, etc. Then you can decide what you need to do to the trunk. I'd suggest that a one-year-old seedling is a bit too young to do anything to yet. Give it two full years, or better yet, three.

But at that point, growing it up, choosing a new leader and chopping just above it and repeating for two or three or more years is the way to go to develop a tree with traditional taper. If you want FAT bases, you use the sacrifice side branches and let them grow unabated for a few years, cut them, then pretty much let everything be for a few more years while the scars heal, tho you can do some work on them. Scars will heal faster, though if everything is allowed to simply grow.

Here's a pretty nice red maple grove from the NC Arboretum's collection. These trees (the bigger ones) are likely 5-8 years old. Maybe more. The American red maple is not the easiest tree to work with.

Thank you Jim. Thank you everyone. As much as I am interested in the traditional Bonsai styles I am more interested in doing a grouping with these and others I haven't grown yet. So I will need to keep them somewhat thin. I figured about three years with most of them. I appreciate the first set of articles by Brent Walsten. Many things I read explain techniques with a small assumptions of past knowledge. Which is fine but I hear a lot of mixed ideas too. I think this will help me envision the end result better.