If gophers are a problem in your garden or property I can recommend an organic green solution you might not have tried yet, the beautiful narcissus bulb. Any type of narcissus bulb, which includes jonquils, paperwhites, and daffodils will be a deterrent to gophers, rabbits, and deer in your garden and property. For simplicity sake, I am writing mainly about gophers and daffodils, but this solution works just as well for rabbits and deer, using all types of narcissus bulbs.
It is important to plant bulbs that are hardy for your climate. Check the packaging information included with your bulbs, or with the source you are purchasing your bulbs from. Generally speaking, these type of bulbs are planted in the fall time frame, and are cold hardy blooming in early winter, depending again on your specific climate zone.
Narcissus bulbs are such a wonderful green solution to deterring gophers for many reasons. Once you plant your bulbs, depth and spacing depends on variety, they bloom year and year. They are simply beautiful to look at, and often very fragrant. Bulbs planted in the ground send out a year round message to critters by actually "advertising" a toxicity odor or fragrance. Yes, that's right. Even before a bulb is bitten into, it is sending a warning, that it has a natural toxicity ability to irritate (burn) the soft tissues of their mouth and cheeks. Gophers find it uncomfortable and stay clear of the bulbs, "taking a hike" out of the vicinity. To some extent by limiting their food source, you are limiting their population, and they have to go elsewhere. Once your bulbs are planted and in the ground, give it some time, and you will notice gophers staying clear of the area near your bulbs.
If you have ever had a gopher problem, you have probably tried trapping, poisoning, drowning, blasting, and a few other gopher terminator techniques. Gophers can be quite a menace taking out a rosebush, grapevine, shrub, or vegetable plant, usually by eating the root system. If you have chickens like I do, gophers can be especially persistent in trying to reach their "pot of gold at the end of the rainbow", the chicken feed bucket and ensuing spillage around it. I even have a 1 1/2 foot wire fencing buried around the chicken coop to discourage gophers.
Try planting bulbs first in a few specific areas, such as along side your chicken coop or the perimeter of your vegetable garden. With time and budget permitting, you can expand your bulb planting as you see your success.
In vegetable gardens where you have a lot of rabbits on a regular basis, try planting bulbs among your vegetables, besides the perimeter. In flower beds, for instance where you have tulips, and a problem with deer, plant your narcissus bulbs mixed closely with your tulip bulbs. All types of iris and agapanthus are gopher, rabbit, and deer resistant, too.
One of my favorite sources for bulbs is the mail order business, www.easytogrowbulbs.com (tel) (866) 725-5361. They sell bulbs for all zones, but specialize in "warm climate" bulbs. Featured in the above photo is their "Erlicheer" Daffodil.