What can I do about these moles in my yard?

Published 6:58 pm Thursday, January 9, 2020

A nice, warm winter day (also known as the eastern North Carolina mini-spring) you’re out for a walk across the yard only to nearly break an ankle in one of numerous soft spongy spots. A closer look generates a panorama of tunnels across your yard that would have made a mid-century mining operation look lazy!

How did this happen? This was not caused by the aliens that make crop circles or gremlins — it is the diligent work of the eastern mole.

Eastern moles spend their time foraging for food under our turf. In doing so, however, they can wreak havoc on the aesthetics of our pristine lawns! Before I discuss options for dealing with the moles, I would like to discuss what they are actually doing in the yard.

Moles actually play an important role in our soil health. Their tunneling serves to aerate our soils and alleviate compaction. The tunneling mixes and disperses soil particles and humic (organic) matter into the soil. Humic matter is an organic source of soil nutrients once broken down by microbial activity. Better aerification aides in bettering the drainage in our yards, allowing for larger porosity throughout the upper soil profile.

If this were an exam we were taking in high school, so far, we would have an A-plus. Moles are carnivorous and while they do consume earthworms, they also consume white grubs in the soil that are feeding on the roots of our turf and ornamental plants. These white grubs are the larvae of several types of foliage-eating beetles — Japanese beetles and June beetles to name a few. Earthworms, on the other hand, consume and digest materials in the soil to produce worm castings. These worm castings are highly sought after for organic fertilizer supplements. So, this is not an ideal situation but one we should be able to deal with nonetheless.

There are several benefits and very few drawbacks to having moles in your yard. It is understandable that in high-traffic areas mole activity just cannot be tolerated due to safety concerns. Think about athletic fields or retirement homes, it is very easy to be injured by stepping in a mole tunnel. The primary tool for management of moles is to remove their food source. Treating the yard for white grub populations is a great management option, but you need to make sure it is worth your time and hard-earned money to do so. Use a flat shovel to peel back a square foot of sod just under the roots. Repeat this sampling method at several locations throughout the yard. If there are more than five white grubs present in the sample area, it is a good idea to treat the yard.

Treatment can consist of a product containing milky spore bacteria in late September or early October. This product works through ingestion so it will take a little longer than an insecticide. However, once established, it will spread on its own, not requiring another application for several seasons.

Insecticides are another route that can be taken to manage white grubs. These are products such as Carbaryl (Sevin) or chlorotraniliprole (Acelepryn G). A full listing of the products available can be found in the 2019 North Carolina Agricultural Chemicals manual online or available for purchase at your local Cooperative Extension office. Make certain to read the label for information pertaining to application, irrigation, timing and safety for your particular product. Typically, the recommendation is to apply these insecticides in late spring or early fall. The imidacloprid products are applied at egg hatch, usually in early April. Remember, when using insecticides like these, you will be removing beneficial insects and earthworms from your soils. Once the food source is removed, you may have a stray tunnel from time to time but most of the upper foraging tunnels will cease to exist, allowing for safe enjoyment of your property.

If you’re having trouble with growing in your home landscape, call the Extension office at 252-946-0111 or email Gene Fox at gene_fox@ncsu.edu. If you’re interested in being a master gardener, there is going to be an Extension Master Gardener Volunteer training series this spring. Sign up for our information list at go.ncsu.edu/bocoemginterest to receive updates. Call the Extension center today to learn more or visit the Blacklands Area Horticulture page on Facebook!

Gene Fox is the area consumer horticulture agent for the North Carolina Cooperative Extension.