We have what seems like hundreds of pocket gophers. We’ve taken to using lots of raised beds with 1/2″ hardware cloth stapled on the bottom.
We also used large pots and “gopher baskets” which go in the ground and should prevent gophers from getting to the roots. I’m not sure how the gopher baskets will work as the trees mature, we’ll see. The other thing we do is plant lots of plants, then some of them survive. (and occasionally the cat catches a gopher).
I too had terrible gopher problems. They were eating everything in sight. I thought I must have at least a dozen and attracting every gopher in the neighborhood. They loved all the organic herbs growing in my yard. It was like fine dining for them. I have heard that planting daffodils around areas you want to protect is a really good solution & one I plan to employ in the future as protection. However, things got so desperate that I never had a chance to try the daffodil soution. Instead I had professional trappers come in and trap them. They used no poison but the traps physically killed the gophers which I was sad about. But the trappers left the gophers in the ground as fertilizer. And in the end they trapped only 4 or 5 gophers that had been doing all that damage! I have not had any gophers since Sept. 6, 2016. I live in the East Bay Hills of San Francisco Bay Area of California. If I get any more gophers, I will definitely call my trusty trappers. Oh, and trapping them yourself to save the money is easy to learn and do. It’s just not for me. Those gophers are just too cute!