Wouldn't grow something from the inside require a very strong force to "move" the already present one? Instead growing from the last "layer" towards the outside would require a lot less force, but perhaps a lot more matter.

Is it even correct that trees grow concentrically?

Now that I think about it, how do plants grow in general? Hahaha

Update: for everyone wondering, yes, my question doesn't make sense because the i.e. contradicts the question. I don't want to correct it because I don't know which part to correct since I was wrong, I thought trees grew new parts inside and pushed older parts outside. So I could correct the i.e. and swap "innemost" with "outermost" but that would mean that people would read a question stating something that is wrong, or I could correct the question and swap "inside" with "outside" but I was wrong and I'm glad I learnt something today. We can all agree that I asked a weird question in a weird way, thank you all for your answers.