Rooting gophers out of your garden
In the movie "Caddyshack," Bill Murray goes to extreme lengths to try to eradicate a gopher which has been tearing up a country club's golf course. In the end, the pesky creature escapes gunfire, flooding, and explosives to dance another day.
The gophers in your garden may not be as tenacious, but they can still be an elusive foe. The University of California's Statewide Integrated Pest Management Program says these rodents, also known as pocket gophers, have large claws, small eyes and ears, and other features suited for tunneling.
A gopher's tunnel system will cover a large area, and you are unlikely to see them above ground. You're more likely to know this critter is in your yard if you spot mounds of loose dirt that have been pushed to the surface as the animal digs a new tunnel.
In addition to damaging your lawn, these tunnels can make it more difficult to cut the grass or erode soil on your property be redirecting water. The gopher is an herbivore and can wreak havoc on your shrubs, vegetables, and flowers. It might also damage your sprinkler system by gnawing on water lines it encounters while tunneling.
There are many strategies for getting gophers off your property. These range from trapping them to simply putting up additional protection for your prized garden plots. There is even the possibility of an explosive attack, though one that is perhaps not as cataclysmic as the one in "Caddyshack."
Consider how you want to tackle the problem. Inga Cryton, author of the pest control site PestKill, says you should determine whether you want to repel the gophers on your property or simply keep them away. You should also check with your neighbors to see if they are having similar problems, as you should coordinate efforts if gophers are affecting multiple yards.
Before setting a trap, you'll want to know where the gopher will be traveling. Push a probe into the soil about a foot away from a fresh mound of soil. When the probe suddenly encounters no resistance after you have pushed it down six to 12 inches, you've found the main burrow.
Once you know where the tunnel is, dig down to set a trap. Roger Cook, writing for This Old House, says you should wear gloves so the gopher will not detect your scent. Loosely cover the trap with earth to block out sunlight, and periodically check the trap to see if it has captured an animal.
Both lethal and non-lethal traps are available. Cryton says one type of lethal trap functions like a mousetrap, catching the gopher around the neck or chest and suffocating it. Non-lethal traps capture the gopher and come with strings to recover the device.
If you use a non-lethal trap, don't just release the gopher into a nearby field. The animal should be taken several miles from your home before it is released.
The University of California recommends removing the trap and placing it in a new location if you have not captured or killed a gopher within two days.
There are two main types of poison to use on gophers. Strychnine-based poisons or baits with zinc phosphide will kill a gopher in a single feeding. Anticoagulant poisons will kill a gopher by causing the animal to bleed internally.
The type of poison you use depends on the characteristics of your home or neighborhood. Cook says strychnine can also kill cats, dogs, foxes, and other small animals that ingest it. This poison should not be used if there is a chance that a small child might be able to access it.
The University of California says anticoagulants are less toxic than strychnine, so you'll need to use a larger dose to be effective. However, this poison is also safer to use in areas with small children and pets.
Poison can be applied through the hole into the tunnel made by a probe. Widen this hole so that it is large enough to insert a funnel or other device to apply the poison. Cover the hole so sunlight does not enter the tunnel, but make sure you do not bury the poison itself.
This method is more likely to be effective if you leave poison at multiple points within a burrow. You should add new bait or try trapping if you see new mounds more than two days of applying strychnine or zinc phosphide or more than seven to 10 days after applying anticoagulants.
If you are mainly concerned with keeping gophers out of your garden, you can take a few preventative efforts to protect these plants. Cryton says you can put down a layer of cloth under a raised bed to keep gophers from tunneling up into your garden. A rhizome barrier, which is designed to contain the growth of root systems will also serve as an underground blockade.
Adding a fence or other barrier around a garden plot will keep gophers from feeding on your plants if they surface nearby. The University of California says underground fencing is a good option for ornamental shrubs and trees.
Cook says mulch may help keep gophers away from your plants. You can also put down gravel around irrigation lines or underground cables to protect them.
Some smells will prove unpleasant to gophers and can help drive them off your property. HGTV says an application of castor oil can be effective in convincing gophers to vacate the premises.
Spread a pound of castor oil granules every 1,000 square feet. As these dissolve, they will produce an odor which will send the animals packing. Distributing over a portion of this parcel and adding more to untreated areas in ensuing days will drive the gophers in a certain direction.
You might attempt to force the gophers out of their burrows by flooding them with water, fumigating them with gas, or using devices that produce noise or vibrations. However, these strategies are usually ineffective or will only cause the gopher to abandon a tunnel and start a new one in your yard.
One long term strategy involves attracting predators to your yard. Set up a nest box to invite owls to roost on your property. While an owl may attack the gophers, there's no guarantee that they will use the nest box or hunt close to your home.
The University of California says the Bill Murray method of gopher elimination is feasible through gas explosive devices. This method ignites a mixture of propane and oxygen in a tunnel, killing the gophers with concussive force and destroying the burrow. However, gas explosive devices can damage property, cause injuries, or start fires if you aren't careful. They are also loud, so they will likely disturb any nearby neighbors.
If you're worried that the gopher will emerge triumphant from all of these eradication methods, you can hire a professional to root it out. These services are likely to have more effective tools, such as fumigation gases which aren't available to homeowners, and they may be able to remove the rodents from your property in no time.