Here's how you can figure out what's eating your garden:
1. Look at the holes/tunnels.
Voles have small, oval,open holes - about 1-2" wide. These are never plugged with soil, and there is often a "runway" in front of the hole. This can be easiest to see when the snow melts and the grass is not too high, or in the winter.
|Vole holes - note that they are open. The winter picture shows the runway clearly.|
Northern Pocket Gophers' holes are about 2-3.5 inches wide, but are almost always plugged with soil. In the summer, the holes are surrounded by large fan-shaped mounds of dirt that are 12 to 18 inches wide and 4 to 6 inches high.
|Pocket gopher hole -- note that it is plugged, and the fan of dirt. The "hole" is not always this obvious.|
2. Look at the damage - is it above-ground or below-ground?
The most common voles we have are meadow voles and montane voles, and these two species mostly eat above-ground parts of plants, including leaves of flowers, grasses and sedges and fungi in the summer. Dried grasses, bark, and twigs are winter staples.
Voles are of most concern when their winter bark-chewing girdles trees and shrubs (they are also problematic in lawns, but lawns less common in the mountains):
|During the winter, a vole girdled this lilac by chewing the bark off all the way around the shrub|
Pocket gophers mostly eat the roots of plants (below-ground). They only rarely come above-ground to eat, and then only a very short distance from their burrow. They use their sense of smell to locate the roots of plants, and then will eat the entire root system. This causes a sudden and unexpected "wilt" of the plant. They can even pull an entire plant underground -- sometimes even under the astonished eyes of a gardener!
|The middle columbine's roots were eaten by a pocket gopher -- look for sudden, unusual "wilting"|