I've tried every possible solution, and the only thing that's worked for me is to plant everything in gopher-proof cages. All of my roses are planted in 5-gallon cages. I used to buy them from the hardware store for about $5 apiece, but I later met a man who makes them for about $2.50 apiece.
Daffodils, garlic, "gopher spurge," and various other deterrents did not work in my garden. The gophers eat everything near the daffodils, garlic, and spurge, and if they're hungry enough, they'll even eat the daffodils, garlic, and spurge. I tried putting kitty litter, dead fish, castor oil, and broken glass in the tunnels and even buried a dead raccoon in one of the tunnels. Those "sure-fire" remedies didn't work in my garden either.
Lining a bed with hardware cloth doesn't work because gophers can travel overland. They simply walk over to the bed and burrow down into it. I thought I had the solution one year and built raised beds on top of concrete, assuming the gophers would never bother the roses and bulbs in those beds. It didn't work. The gophers climbed up into those beds, burrowed down, and ate all of the bulbs and roses.
I haven't used traps because they would be a full-time job around here. One of my neighbors doesn't want to pay for the cages and uses traps. He has dozens of traps, catches dozens of gophers regularly, and the rest still eat everything they like in his garden.
The cages are a big investment if you grow lots of roses and other plants that appeal to gophers (lilies, tulips, irises, daylilies, fig trees, etc.), but they cost less than the plants you'll lose if you don't use them.
