By Pat Naughton
Controlling mole mounds can be frustrating. Fall is a time when critters are thinking about two things, food and habitat. Moles feed on insects, worms, and other invertebrates living in your soil. This time of year they live close to the surface and easy meal for moles. As the soil temperature gets colder insects and grubs will go deeper in the soil and the moles will become less active.
It may appear by the number of mounds that a large family of moles must be present. Not always is that the case. Extensive damage can be caused by one mole, creating up to 150 feet of new tunnel each day. Moles often eat up to 100% of their body weight in worms and insects each day as the travel through a lawn at speeds up to 18 feet per hour.
Trying to get rid of insects in the soil by applying pesticides throughout the year to reduce the mole food supply may sound like a good idea but rarely effective and not recommended. Soil pesticides target specific types of insects like grubs. Moles feed on a variety of insects including earthworms. Earthworms are beneficial to lawns. Fortunately most lawn insecticides do not kill earthworms. In some cases reducing the food supply with pesticides will make the moles travel farther in search of insects and result in more damage to the lawn.
What are effective alternatives to pesticides? The following are some methods for controlling moles and their effectiveness based on research.
Poison baits such as Talpirid has been found by actual research to be effective. Talpirid looks like earthworms. It is expensive. You can cut the worm bait in half or thirds to save money and still be effective.
Direct trapping is the most effective means of controlling moles. Whether using baits or traps it is important to locate a main tunnel that moles frequent. To do this, step on all mole mounds, then the following day look for mounds that have been pushed back up. To help conceal the trap, step on the tunnel on both sides of the trap. Packing the soil and reducing the moisture will make the habitat less attractive.
Discouragement products that contain castor oil are widely available and have shown some success. These products come in granules or liquid that is applied with a hose. Start close to the house and treat a band 5 to 10 feet. The following week retreat the area and expand another 5 to 10 feet until the lawn is covered. The goal is to move the moles away from the lawn.
Mothballs and moth flakes placed in tunnels are not effective or inconsistent.
Planting a barrier of plants that are toxic such as castor beans, marigold, or caper spurge (Euphorbia latharis) have not been found to be effective.
Vibration and ultrasonic devices emit vibration or sound into the ground to discourage moles. These devices may look nice in the lawn but are not effective.
Smoke cartridges are a Caddy Shack technique that may be fun but not effective.
Poison peanuts are not like a mole’s diet of insects, therefore not effective.
Home remedies are often recommended by neighbors. Substances like chewing gum, hair, and pepper are typically touted as doing the trick. Although there is no research to support these claims, if it works for you, go for it.