My birch tree is growing pretty well this year, as it has in years past.. I repotted this spring. I was thinking about defoliating this summer or partially defoliating this summer to get some more light into the middle of the tree. Does anyone have experience defoliating birches? Is it similar to maple? I need to prune it this week sometime, as well.

I have several but I have never done any partial defoliation, I just pruned to get light in, they do not seem to grow much after pruning so I doubt there would be a new flush of leaves. It is not the same as Maple, but I don't defoliate Maples either.

the trims that I have done, have always produced decent new growth... so that's why I was wondering about defoliation. I do know that one must be careful with pruning too much... they don't seem to back bud as easily as some.

You could try it on one that is not valuable and see what happens. The problem I find is that they can drop a branch at will, so it could precipitate a branch dying.