What is causing holes to appear in my yard? ASK THE HORT AGENT
Question What is causing holes to appear in my yard?
Answer The answer is simple. The absence of dirt is causing the appearance of holes. The real question is “What is moving my dirt?”
Like any horticultural mystery, this one can be solved by getting the specifics of the problem. Culprits can be chosen for a lineup depending on the size of the hole, number of holes and distribution of the soil. In the interest of brevity, I will only examine potential culprits using the size of the holes they make.
First, how big is the hole? Anything larger than 6 inches is probably an animal like a raccoon, skunk, dog or groundhog. These animals can be digging for food or building a new home. A dog may actually be digging a hole to catch another hole digging animal.
If the hole is 2 to 3 inches in diameter, then the suspects get more diverse. The furry animal suspects include squirrels, moles, voles, rats (small difference between rats and voles) and shrews. Cats also dig holes, but they usually cover them up when they finish their business. Smaller holes can also be caused by non-furry animals like frogs, turtles, birds and snakes. Not all snakes dig holes. However, the hognose snake has a specially designed nose for digging.
Crayfish or crawfish also dig 1 to 2 inch holes. Their holes are usually near water and capped off with a mud castle. Crawfish are the original sand castle kings.
Small holes, around 1 inch or less, are probably caused by insects. Cicada killer wasps and ground bees make holes primarily in the lawn. Some insects actually make holes when they are digging out of the ground. Cicadas, pecan weevils and Japanese beetles are a few of many insects which live under ground when they are immature. During the spring or summer they wait for a rain to loosen the soil so they can emerge as adults.
Worms are the exception to the insect rule for small holes. As they tunnel around, occasionally they pop their heads out. This process makes holes, but they are not insects.
There is another category of non-living things which may displace dirt. This group includes aerators, water dropping off the roof, fallen limbs, and meteorites. Meteorites can vary in size from 1 foot across to the size of Yellowstone National Park. Large holes can also be caused by county, state or federal contractors. Typically, the federal contractors would fall into the non-living category. State and county contractors are in a category of their own.
Another non-living cause would be buried organic matter. Building debris, wooden caskets and dead tree roots will rot away and leave a cavity which looks like a hole.
I guess the bottom line is nearly everything which crosses your yard may leave a hole. Rarely is a hole causing damage to a plant. If the holes aren’t killing something, then ride it out.
For info on making holes in your yard, check out http://www.oznet.ksu.edu/library/HORT2/MF2130.PDF If you have questions, then call 910-893-7533 or email me at gpierce@harnett.org
You can also buy one of those wildlife cameras that will take cool pictures of elusive animals digging holes like a hognose snake or Department of Transportation worker. Maybe too elusive?
Gary L. Pierce
Horticulture Extension Agent
Harnett County | 
