Used Kitty Litter
Gophers hate "bad" odors or odors that they are not used to, such as ammonia. The smell of ammonia can send the gophers away from your garden. One of the drawbacks of using store-bought ammonia is that it is also a chemical that can be harmful to the environment. An excellent substitute that you can use is a used kitty litter to fill in the gopher holes. The used kitty litter with the cat’s urine produces ammonia naturally, which can produce odorous gas that gophers cannot stand. Place portions of the used kitty litter into the holes. Kittly litter is a naturally decomposing product; therefore, it should not be harmful to your garden. If you are concerned about the smell of urine in your garden, make sure to cover the holes right away with additional potting soil. Of course, you should already own or plan to own a cat if you plan on using this method. You can also ask a neighbor with cats for their used kitty litters.
Gophers may like damps soils or survive from normal garden irrigation; however, they do not like the flood. Use a garden hose and insert it as deep as possible into the gopher holes. Then, turn on the water and leave it on for about five minutes or longer. You can force the gophers out of their burrows by flooding the ground. Wet soil will prevent gases from entering or leaving the burrow. The sticky and wet soil also irritate the gopher because they stick to their claws and fur. Make sure the water runs continuously in order to reach the elaborate underground gopher network. Use grey water or water collected from rain, shower, laundry and dish washers in order to save on your water bill. Also, make sure that when you use this method that there are no high spots that gophers can use as retreat points.
One thing about gophers, they really hate awful or bad smell. Just like the ammonia, a fish emulsion is also irritating to the gophers. Water around your plants or shrubs regularly with fish emulsions to prevent gophers from digging. If you see gopher holes, drop some fish emulsions into them to get rid of gophers. You can buy fish emulsions from the grocery or Asian markets. You can also use carcases of dead fish. If you have an aquarium that you clean regularly, you may also try pouring the dirty aquarium water into the holes. The water stench would send the gophers packing.
Oleander, Castor Bean, Garlic and Onions
Gophers may go digging in your flower and vegetable gardens to look for food; however, there are plants that can kill or, at the very least, irritate them. Castor bean plant is poisonous to gophers. When gophers eat the castor bean plant roots, they can die. Oleander plant roots have similar effect. Many gardeners also claim that planting garlics and onions all over your garden can get rid of the pesky gophers. The putrid odors coming from these plants can be irritating to the gophers; therefore, they will avoid a garden with plenty of these types of plants.