Moles and gophers and voles Oh my!
Ah, spring is in the air, a time for romance, and rebirth, and lots of babies. Rodent babies that is! Those miniscule creatures that seem bent on destroying our gardens can come in herds this time of year. In fact they do breed quickly, and although gophers live individually and are territorial, when the babies leave the nest and look for their own homes they will appear everywhere. A group of moles happens to be called a labor, and if you have these guys in your yard, that is what they may cause for you! A collection of voles on the other hand, is called a herd, and can eat most everything in their path.
What exactly is the difference between moles, voles and gophers? First, what they have in common: all live underground, make tunnels, breed prolifically and become pests in large numbers. The differences, however, are more important. Gophers are herbivores, and eat plant roots, even drag whole plants down into their tunnels. They are most directly responsible for large scale plant damage. Moles, on the other hand, are cute little blind carnivores, with insects being their meat of choice. Very often they go after grubs and are actually doing our lawns a favor. Problem is, their tunnels are shallow, and if your lawn is riddles with them you will cave it in if you walk on it. Gopher tunnels are deep, but they make exit/air/feeding holes all over, and spread dirt out in a horseshoe shape around them. Voles are also called meadow or field mice. While they look like a short tailed mouse, they are actually cousins of the lemming. These guys eat mostly plants, some insects. They especially like tender little seedlings in our veggie gardens. They will also eat bark on tender woody plants, and can girdle and kill them. They make their homes in tunnels under brushy areas. You generally don’t see much evidence oftunneling with these little guys, you just come out in the morning and all you lettuce and spinach starts are gone!
So what do you do if you suspect garden damage from these guys? First, try to positively identify the culprit. Gophers are mainly active feeding at night, but occasionally active in the day, and leaves holes with large dirt mounds around them. Larger plants may wilt for no apparent reason, but if you tug on them they come right up, sans a root system. Smaller plants may disappear all together. And you may see your cat sitting still for hours staring at a spot in the garden- Fluffy is waiting for the little rascal to poke its head up. Dogs may go after them too, digging huge trenches and doing more damage than the rodent in the process. In the wild, the action of gophers in the soil are beneficial for both plant and animal communities. Gophers mix and deepen soils just as effectively as if the fields were plowed, although considerably slower than by human methods. Gopher mounds cover surface vegetation, thus incorporating sometimes over 50 percent of surface plant material into the soil. By-products of the gopher and unconsumed plant material enhances the fertility of the soil. Their tunnels permit deeper penetration of air and water into the soil. The tunnels also collect runoff of early melting snows and rain storms.
Moles and voles are more active at night, so you are less likely to see them. Mole tunnels are distinctive in being subsurface, easily broken through when walked on but rarely do you see an exit hole. Vole evidence is even more rare, and their presence can be hard to deduce. Owls are a natural predator, and you can find instructions to build or buy nesting boxes for these guys on the internet. There are traps and bait specifically for these varmints, check with the nursery for details.
Gophers are by far the most damaging in our area. There are a number of ways to combat these vermin. Traps can be set, but you must access their tunnels to be successful. There are a number of poison baits that work well, but be careful if you have pets, especially dogs, as they can succumb to the poison as well. Other methods that may have some limited success are smoke bombs, flooding ( starting to hear the Caddy Shack music yet?), hair or chewing gum down their holes, routing the car exhaust down the hole ( NOT RECOMMENDED). There is also a granular or liquid repellent that will repel gophers and moles. It takes about a week for the critters to leave, and must be reapplied in about 3 month intervals. Put it on your calendar if you use this, because if you go too long between applications, those darn things will come back with a vengeance ( author’s experience). This product is Castor oil based, and while could be toxic to pets (if ingested in quantity), they seem to leave it alone as well. Oh – and don’t kill the snakes, they eat these guys too, as do hawks and owls.
If you have the opportunity, plan ahead when you are thinking of planting. Raised beds with hardware cloth on the bottom, wire cages around the roots new transplants, or planting in pots will keep out gophers. This is especially important for edibles, because with the exception of blueberries, our favorite foods seem to be theirs also. (Although there is no scientific evidence for it, they may not like the highly acidic soil blueberries should be residing in. They have eaten everything around them, and not gone into the blueberry bed, pH 5 – Author’s observation).
If you need some plants to put in the ground and forget, there are some that most mammals detest. Highest on the unpalatable list is Euphorbia, most kinds. Daffodils are also immune, but I have noticed them moved in high activity areas. Other ornamental plants with some toxicity they tend to leave alone – Hellebore, foxglove, marigolds, and amaryllis. Some other plants that show up often on "gophers won't eat" lists are columbine (Aquilegia), artemesia, ceanothus, rock rose (Cistus), breath of heaven (Coleonema), lavender, Mimulus, heavenly bamboo (Nandina), Indian hawthorn (Rhaphiolepis), rosemary, and native or other perennial salvias. Keep in mind, however, that food choices of mammal pests are not entirely predictable. And before you ask, yes the above plants are usually ignored by deer as well. Yeah!
Of course, if you read all the plethora of info on the internet and are still not sure what you have, take a picture of the business (or deceased plant) if possible and talk to a nursery specialist. They can help you at least limit the damage and have a productive spring. Happy Planting!
Disclaimer – we are talking about live creatures with a mind, though small, of their own, and they may not have read all the literature. Physical barrier is always the best way to limit pest damage.