Your carrots have finally reached harvestable size—you can tell from the broad shoulders slightly protruding from the soil that the crop is going to exceed expectations. Excitedly, you bend down and gently tug on the feathery green leaves. Pop! Up come the leaves and the top of a carrot—but wait! Where’s the rest? All you’re holding is a quarter inch of orange. The rest of the carrot is missing! Confused, you stick your shovel into the soil to bring up the next root, but it suddenly plunges downward, encountering no resistance. There’s a tunnel under your carrot bed. Grrrrr!
The heavy snowfall took a while to melt, but finally your dormant lawn emerges from under its frozen blanket. Last time you saw it, it was perfect turf, smooth and even. But now, it looks as if an army had performed maneuvers across your yard! Shallow furrows run here and there around islands of still-intact grass. What in the world?!
You’re quite sure you planted the flowers in that spot. You remember digging the hole and carefully sliding them out of their pot and into the soil. But now all you find is mulch. Where did the plant go? Careful digging exposes a gnawed off stub flush with the soil. So much for the $7 perennial! Maybe the roots will re-sprout?
There is a lot of confusion over which pesky critter we should blame for causing damage in our landscapes. Was it moles or voles, and what’s the difference anyway? What about gophers—are they rodents or turtles? What did the damage—and what can we do to stop them?
Let’s list the suspects. Front Range gardeners do not have to contend with moles, thank goodness. (I’ve seen the damage they do in other parts of the country.) In any case, they eat grubs (beetle larvae), not plants. However, we do have pocket gophers, voles, and rabbits, and occasionally ground squirrels and prairie dogs, and they can destroy your yard. Today we’ll address pocket gophers. Next month I’ll talk about voles. You can read my rabbit article here.
Pocket gophers are rodents. (In some parts of the South, a “gopher” refers to a tortoise.) There are 35 species scattered across North America, four of which are found in Colorado. Size ranges from five to 14 inches long; picture an overgrown gerbil. You can identify a pocket gopher hole by the semicircular fan-shaped mound around it. Some tunnels are closed with a soil plug, as on the right, below.
Tunnels are two to three inches in diameter. They may be four to 18 inches underground, or form a snaking mound along the surface that appears after the snow melts in spring. Left undisturbed, these burrows may reach 200 yards in length with dozens of branches and hundreds of mounds.
They’re admittedly kind of cute, with their big front teeth, but pocket gophers are a tremendous problem if they’re in your yard. They eat roots, lots of roots, and are the culprit in my first example. (Yes, this actually happened to me—they also ate the roots of my four apple trees, causing the 7-year-old trees to fall over dead.)
It’s very tempting to take a lethal approach to eliminating these incredibly persistent critters, but they do play a significant role in the ecosystem, aerating the soil and providing meals for hawks, coyotes, snakes, and other wild predators. Besides, animals in adjacent areas will quickly move into a vacated habitat.
Colorado State University suggests a better approach is exclusion, although they agree that the effort and expense involved may be impractical:
Pocket gophers can be excluded from valuable plots of ornamental trees and shrubs with a 1/4 to 1/2-inch mesh hardware cloth fence buried at least 18 inches. The bottom of the fence should be bent at a 90-degree angle so that a 6-inch apron of wire projects horizontally toward the gopher. Place the fence in shallow soil at least 2 feet from the nearest plants to avoid root injury. … Ornamental beds and vegetable beds can be protected by lining the beds with 1/4″ hardware cloth. … It is recommended to put a fence at least one foot high around the beds to keep the gophers from going over the barrier.
I’m not sure 18 inches is sufficient. My husband built me a small greenhouse at our previous home, laying two courses of cinder blocks below ground level before adding 2 x 4s and repurposed sliding glass door panes. One spring I stepped inside to start planting lettuce and was startled by an equally surprised pocket gopher. Yes, it had tunneled under the cinder blocks and had happily set up housekeeping in the relative warmth of the greenhouse. At least I didn’t have to do much digging that year—the ground was already full of mounds and tunnels.
Pocket gophers are one of the most troublesome pests we have in Colorado, perhaps equal to, or even worse than, deer. I miss the amended soil and numerous beds of my old garden, but at least our new yard doesn’t have gophers. Thank God!
For more information, read CSU’s fact sheet, “Managing Pocket Gophers.”
Plains Pocket Gopher photo from Wikipedia.