In your experience do gopher baskets have any effect on the growth of the root systems of trees - do they slow or restrict growth in any manner, or prevent roots from growing as extensively horizontally as they normally would, or do roots simply grow right through them like they aren’t there?
Good question, and I think the answer is that they probably do limit root growth in the long term. I initially had the same concern, and there’s not a lot of information on this online. I decided to make gopher baskets for all of my fruit trees since we have moderate gopher pressure and my neighbor has lost a tree or two to gophers. I used either heavy duty mesh wire 1/4” or 1/2” regular chicken wire and wrapped the chicken wire around itself twice to make smaller gaps. I’ve made 50-100 baskets. They’re a pain to make but worth it. My oldest trees are 4 years old and seem to be doing fine, fruiting well. I think over time the wire will restrict the roots, which is probably a good thing since I want to keep my trees small. The wire will probably degrade, but it could take several years since I used heavy wire for many of them. At some point, I will end up digging up a tree and get a better idea of the root structure with the wire basket in place.