Japanese Black Pine seedlings separation

Hello, looking better already.

There's a video a like on how to proceed with JBPs from seed, I like to watch it every once in a while.
You'll notice the importance of inducing and preserving inner candles and buds, so you can start the structure after you're about done thickening, after a few years it becomes very hard to make them bud back

You might have learned that pines can bud from between needles, so it helps to clean them but leaving needles in strategic points

Here's one of mine JBP, that's the lower part, sacrifice branches extend for about a meter, they're on big pots tho.
You can see that it has lots of buds that will be selected to compose the structure of the tree once I remove the sacrifice branches.

I’ve figured to give an update: all 3 trees are still alive
One of them isn’t so healthy (it’s needles turned lime color). My suspicion is that it was in an area with not enough sun, afterwards I have moved it an area with full sun (which shocked the tree).

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I am well aware that the one in bonsai pot is gimped. The other two, the were growing weird so I had to do some cuts that will graduallly give them shape.

Happy to see they're alive and improving, that middle one is getting a nice shape.
The needles are quite elongated, but that it's because their position I think.
The first one, you should look forward to cut that older branch, and start with those two lower ones, in my opinion, those newer branches with a lot of needles bud back more easily...

About plucking old needles, that would be by winter (when it's also time to wire, if needed), but you have to be sure that the new needles are suficient to mantain the tree until it wakes up on spring, however, I don't see much you need to pluck, because where you want new buds to emerge, you don't pluck, so you can get needle budding.