Prune while you can. A lot of threads on here today showing poor branching structure.

If you want a vase shaped tree and it won't fall on your house let it go. Some folks will say trees have been growing for millions of years and have it figured out thanks to evolution. I think isolation in our open yards are something they didn't deal with in the cretaceous period though.

SO unless you have other reasons simulate the effects of some lower growing competition and prune what you can.

When do Chestnut Oaks want pruned? Fall? Can ya put a picture up?

Unfortunately I don't have a digital camera and my cell phone is pretty basic. One of these days I,ll get a camera. I am worried about future breakage, the way it looks is not a problem. What do you mean simulate the effects of some lower growing competition?Do you mean to plant around the base? Like a shrub or something?

I should be more clear.

I mean limb it up to simulate the effects of growing in a forest like most trees are designed to do.

SOMEPLACE there has to be a link to a more eloquent wording, but I consider tight "V"'s in branch to trunk angles to be bad and closer to 90 degree angles good.

Significance of narrow crotches varies with species and cultivar, if you tree to eliminate all narrow crotches on a species that often produces them or a fastigiate cultivar you may end up with very little tree left. What is happening below where two branches meet is what determines the likelihood of future breakage. Maybe Google "included bark" and "bark ridge" for more on this.

I read the article on included bark and understand the reason for breakage in narrow crotches after seeing the pictures, before seeing the pictures I thought it was that the branches didn't get thick enough because of the two branches being too close instead of the sectioning off thing that the pic shows. I searched online for pics of chestnut oak quercus montana or quercus prinus ( saw both names)and the older trees look sort of vase shaped anyway. Thanks for the input Toranado also.