Hi all.
I have been wanting to grow Japanese Maple from seed for a long time, and have done lots of research. However, my research has resulted in a query I can’t find an answer to.
All the maple I have seen growing from seed in my research seems to shoot up tall very quickly, and have no lower branches. How are lower branches encouraged?
I assume you cut the main stem down, and new shoots will emerge. However, I don’t want to kill them by doing this if it is incorrect.
I also don’t want to grow a nice thick trunk and then cut it down to size leaving an unnatural top. If I keep it short from the beginning, will I get a better tree?

Has anyone got experience in this?

What I do, I let the seedlings grow for the season, then trim back in winter or late summer. n late summer you have less thickening but you might get a little bit of late summer growth, adding a few short internodes, which later on will allow side-branches.

Internode length is the most important thing to work for if you do not want to graft.

A japanese maple will shoot everywhere if trimmed and defoliated in mid-spring.

Just let them grow freely for the 1st 2-3 years (additionally add some movement in the trunk after year 1). After 2+-3 years you can cut the trunk down to a low internode and new branches will grow from there adding some taper in the trunk. Peter Adams' and Andrea Meriggioli's maple books are a good way to learn about how to grow maple bonsai trees.

I started a batch in 2017: shumibonsai.wordpress.com/tag/japanese-maple-from-seed-2017/

Also if you have like 100 seedlings and don't know what to do with all of them, here's a great idea for at least 9

Thanks both. Really useful.
And thanks for the links and ideas I really want to do the clump of 9 trees now.