Exclusion or gophers is almost impossible due to the cost of fencing and excavation work. To keep gophers out of an area, you should dig a trench 3 to 6 feet deep and put up a chain-link fence with a close mesh to keep them from burrowing under it. The wire should be thick enough not to get chewed up and deep enough not to sink in. The fence should also be high enough that they cannot climb over it. Gophers usually just dig tunnels, so underground exclusion is the most important factor to focus on.
Unfortunately, you have to do this on your entire property, so the time, cost, and actual feasibility aren’t worth it, unless you have very expensive flowers. What most homeowners and landlords choose to do is deal with them when they come. Most people will go online and find a solution. The problem is not all that “solutions” are going to help. The biggest “fix” scam is ultrasonic squirrel eradicators (also sold for moles). I can’t tell you how many times I’ve gone into a house with a gopher hole in one foot from one of these devices. Bottom line, don’t waste your money.
Another home remedy for newbies I see is to flush them out with a water hose. Although not impossible, the probability of this succeeding is very low. Gopher holes are designed for your safety. They plug their holes to keep out light, rain and predators and have many tracks in different directions. A garden hose will struggle to get enough water fast enough to drain a gopher and you still have the option of getting out of one of its holes to escape the water.
Smoke bombs are often sold in hardware stores and may have limited success. You must cover all the holes with the smoke bombs to stand a chance. The idea is to kill the gopher with carbon monoxide, but the holes usually fill with enough smoke to suffocate the well-hidden, well-protected pest.
Home improvement stores sell baits (poison) to kill gophers. Poisons available to home and property owners without a pest control license are low dose and require multiple feedings to be effective. There may be success with these low dose formulas, but not as much as a professional strength squirrel poison used by a pest control company. Caution: Your pets may dig up this poison or unearth a poisoned gopher and a secondary poison that can be fatal. Call your local veterinarian immediately if you think your pet may have ingested any poison.
Capture is available to both homeowners and professionals. Traps are set in squirrel tracks and no bait is required. Squirrel traps can be placed on the tunnel track, which requires two traps to be placed, in each direction, in line with the tunnel route. Another way to set a trap is to dig a recently used gopher hole and set a trap at the entrance with light shining through the trap. Light shining through a gopher hole is very dangerous to the gopher’s well-being and it will go to investigate and plug up the hole’s entrance. When the gopher reaches the entrance of the trap, he makes it jump and “no more gopher.”
Pest control professionals use fumitoxin granules, also known as aluminum sulfide. You need a restricted use license to purchase this pesticide due to its high lethal potential. This method is very effective. Compared to the poison a gopher eats, the fumitoxin method has a low secondary exposure risk. With poison, a dog or cat can dig up the poison or eat a poisoned gopher and get a secondary poison. This is often fatal to the household pet.
Fumitoxin works by releasing phosphine gas, which is extremely toxic to pocket gophers. The gas is expelled throughout the tunnel system. Because pest control professionals are the only ones who can apply this method, the fumitoxin is placed in strategic locations where they know it will be effective. My pest control company, Rodent Guys, uses the almost exclusive fumitoxin method and we have achieved almost 100% success.
Pest control service companies, like mine based in La Verne, CA, that do gopher extermination will often guarantee the job done. If you live in an area next to wildlife or open fields, you may need a monthly service to fix your problem. Most homeowners don’t have the time, patience, or desire to try this on their own. Hiring a professional who knows what to do and has the resources is recommended for large properties or heavy infestations.
You can find more information about gophers and general pest control on my website at http://www.rodentguys.com.