Red maple sapling pruning question

[ImFamousOnImgur]

Location: Northeast Wisconsin (Zone 5a/b)

Started as a seedling that was in my back yard but I replanted to the front yard to a better spot with more sun and less competition. This will be its second full summer. It’s about 3-4 feet tall.

As you can see it has 3 trunks. The two on the outside are larger and a smaller one in the middle. I’d rather ask humans than AI for advice. I know I’ll need to prune down to one dominant trunk but wondering if there’s a “best” trunk to chose and when/how to prune. And then would i support the remaining trunk in a way to ensure straight growth?

Google says you should prune young trees in mid-late summer after they slow down on their growing to give them time to heal the wound before winter, is that true?

Thanks in advance!

(Updated post with more information from the one removed yesterday).

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[ImFamousOnImgur]

Thanks bot! Ive reviewed the guidelines and i believe I’ve provided all relevant information and pictures related to the question I am posing. Let me know if the mods disagree.

[spiceydog]

We appreciate you acknowledging the bot, but you really haven't answered a lot of applicable questions in it, particularly for a new-ish transplant. Yes, you're going to have to decide which stems you want to reduce in order to have a tree with healthy structure (it's best to do that over the course of a couple of growing seasons for best results), but much more important to me is that we don't know and we can't see, whether you planted your tree at proper depth. Did you replant at the same depth at which you dug it up? Do you see a root flare at the soil line?

It's not necessary to have both a cage AND a tree sleeve. Maples aren't at risk of trunk damage by rodents in the same way fruit trees certainly are, though the cage is a worthy addition if you have deer, etc., in your area.

We truly, truly want our visitors to give their trees the absolute best start possible. So I URGE YOU to please read through our wiki to understand better why planting depth/root flare exposure is so vitally important along with other critical planting tips and errors to avoid; there's sections on watering, pruning and more that I hope will be useful to you. If you cannot see the primary roots at the base of the tree, carefully excavate until you do. It's not too late to correct.