Well these pests vary a lot in their feeding habits and are very difficult to control. For moles, patience often works the best since these carnivores are in your garden to dine on earthworms. As the weather warms up and dries, the worms go lower into the soil and the moles follow. However, Liquid Fence sells a pretty effective repellent I've heard has been pretty successful. It's for sale at most garden centers and home stores. Now, gophers are generally not a problem in backyards. They dig large mounds, but are mostly found in pasture land. Are you sure you have gophers? Could you have ground squirrels or chipmunks? Not saying you are incorrect, but just want to be sure that a gopher is what you are dealing with. Anyway, there are also repellents for gophers. I believe the Messina company has one which would be for sale at the same locations as Liquid Fence.