So I collected this maple as a seedling in April with the intention of untiring it into a bonsai. I plan to buy a bonsai in the spring to practice pruning l, wiring etc.

But my question is why no branches at all on this maple? Just a straight trunk (hard to see but it's a good two inches around already). Should I be worried? Will it survive the winter?

RPBonsai wrote: So I collected this maple as a seedling in April with the intention of untiring it into a bonsai. I plan to buy a bonsai in the spring to practice pruning l, wiring etc.

But my question is why no branches at all on this maple? Just a straight trunk (hard to see but it's a good two inches around already). Should I be worried? Will it survive the winter?

way too young to have any branch system.... the tree looks healthy, let it grow wild to develop a trunk, then focus on branches in 10-20years. You should plant it in the ground if possible. You will have to take care of it this winter, or it might not survive because it is a very young specimen.

You said yourself it was a seedling in April. What do you expect it to grow like a cherry tomato plant?. It is a tree, they take a very long time to develop. How much did you grow as a kid in less than a year? and humans live what, 80 years?. How long does a Maple live?

Also, it seems to me this species isn't very suitable due to it's very large leaves.