Mole Control in Lawn and Garden

Hole Identification: Moles vs. Voles and Other Rodent Pests

Image showing what a mole looks like.
What does a mole look like? This image shows one. How does it differ from a vole? The latter is more mouse-like, with clearly visible eyes and ears. Geoff du Feu/Getty Images

Why is mole control necessary? Because, mole holes are unsightly on lawns and can be disruptive to the root systems of garden plants. These pests lurk in their subterranean fortresses throughout the year. But gardening and lawn-care enthusiasts are made acutely aware of them mainly during the spring and fall, especially after periods of rain, when they push mounds of dirt up to the ground surface.

The mole's preferred diet is a carnivorous one: insect grubs, adult insects and earthworms (that's why one of the easiest first steps you can take in this pest-control project is to apply a product such as Grub-X on your lawn, thereby removing a food source). Neither the eastern mole nor the star-nosed mole is a rodent, and therefore any gnawing damage you detect on plants is unlikely to have been caused by moles. Rodents do, however, make use of mole tunnels to attack plants underground -- making moles accessories to the crime.

Moles produce two types of tunnels, or "runways" in your yard. One runway runs just beneath the surface. These are feeding tunnels and appear as raised ridges running across your lawn. The second type of runway runs deeper and enables the moles to unite the feeding tunnels in a network. It is the soil excavated from the deep tunnels that homeowners find on their lawns, piled up in mounds that resemble little volcanoes.

Mole Control: Pest Identification

Since moles are not the only animal pests responsible for runways in lawn and garden areas, they are often confused with these other pests -- the pocket gopher and the vole -- and you must learn the difference between them. Because these lawn and garden pests are rarely seen, it makes more sense to base identification on the signs they leave behind, rather than on how the animals look.

After all, you may never come face to face with these subterranean foes! And proper pest identification is the first step in effective mole control.

Whereas mole mounds, as stated above, are volcano-like in appearance, pocket gopher mounds are different, being horseshoe-shaped. Voles, meanwhile, leave no mounds at all behind. Instead, voles construct well-defined, visible runways at or near the surface, about two inches wide. Vole runways result from the voles eating the grass blades, as well as from the constant traffic of numerous little feet over the same path. And if any of these lawn and garden pests can literally "beat a path" through the grass, it is the voles. Rabbits do not have anything over this prolific rodent!

On Page 2 some mole control methods will be introduced....

The best bets for getting rid of moles are traps, but many people are reluctant to use them. There are also poisons and mole repellents available. We will look at the repellents first.

The formula for commercial mole repellents, such as Mole-Med, is based on castor oil. An example of a commercial mole poison is Moletox. When using mole repellents or mole poisons, you must often water the area where you'll be applying them, so that the repellent or poison will permeate the soil.

Water the area well both before and after applying the mole repellent or poison, if instructed to do so on the package of the particular product that you choose. Re-application may be necessary.

There are traps designed specifically for killing the pests, and they go by scary names like:

  • Scissors mole trap
  • Choker mole trap
  • Harpoon mole trap

You can also trap moles using a small live-trap, such as is put out by the Havahart Company. The problem with Havahart traps, though, is that you still have to get rid of the live critter after you've trapped it. In some states animal relocation is even prohibited.

Trapping in the early spring can eliminate pregnant females, effectively nipping in the bud what would be a greater problem later. Where you place the trap is critical to your success in trapping. You'll want to place your mole trap near active feeding tunnels (that is, the shallower of the two types of tunnel described on Page 1).

Here's how to tell if a feeding tunnel is active:

  • Using your hand or a trowel, flatten sections of the moles' raised ridges of soil.
  • Mark these sections with something bright (perhaps some old ribbon that you can tie to a stick to make a little flag), so it will be easy to relocate them later.
  • Check back within 12 to 24 hours, to inspect the ridges you've flattened.
  • If the ridges of soil are pushed back up, you'll know that Mr. Mole regards this tunnel as an active tunnel. This is where you'll place your trap.
  • Cut out the turf over the active tunnel, and remove the soil right down to where the moles have beaten their path. Moles don't see well, so they'll stumble right into the trap. While their vision is poor, however, moles are sensitive to the touch. This means you can't leave any loose soil in the path leading up to the trap, or the moles will detect it and back off.

Seek alternative methods for getting rid of moles, rather than using these dangerous poisons or killing traps, especially if you have pets or children. Mole-Med mole repellent is advertised as a safe alternative; but when you consider the likelihood of needing to reapply it, this method of getting rid of moles could be expensive. Page 3 discusses cheaper alternatives for homeowners of a more experimental bent....

Many do-it-yourself mole control success stories focus on methods that involve planting barriers composed of certain plants whose smell moles find offensive. While this alternative way (an instance of "companion planting") is probably less reliable than the use of traps, pesticides or repellents, it is also a lot more fun! In addition, these are visually appealing plants that are worth growing in their own right.

So if you need to deal with these pests but are not desperate for immediate results, then using certain plants as a natural way to control moles may be the right option for you.

Several bulb plants are said to repel moles. One is the well-known daffodil. Two of the others are also classic spring bloomers, although not quite as widely known as the daffodil: Siberian squill (Scilla siberica) and crown imperial (Fritillaria imperialis).

Squill bears pendulous bell-like flowers in shades of lavender, blue, white or pink. Over the years squill will multiply and fill in an area. Squill naturalizes in zones 4-8.

Yellow crown imperials such as Fritillaria imperialis 'Lutea' bear six to eight pendulous yellow flowers. The scent of its bulbs is said to resemble that of a fox, which certainly would not be a pleasant smell for moles. These plants reach about 3 feet in height. Zones 5-7.

The Allium genus of bulbs comprises not only garlic, onions, leeks, chives and shallots, but also ornamental flowering onions, such as Allium schubertii.

The latter are sometimes simply referred to as "Alliums." This unusual flowering plant ranges in size from about 6"-5' in height. While garlic is also reputed to be a mole repellent, Allium is a better choice if you are seeking a living mole repellent strong not only in scent, but also in aesthetic qualities.

Allium giganteum is one of the taller ornamental Alliums, reaching 3'-5'. Flowers are purple and form round clusters with a width of 4"-6". As its leaves die back in early summer, you’ll want this plant to be screened from view. To accomplish this, simply plant Alliums behind other plants that will obscure them as Allium’s foliage dies. Bulbs can be planted in fall or spring, 6" deep. Cold hardy to zone 4.

On Page 4 we'll consider three more plants, including two that are perhaps the most interesting "living mole repellents"....

The Mexican marigold (Tagetes minuta) is a malodorous plant often used for medicinal purposes, and it's widely held to be a mole-repellent plant. Companion planting is an example of a specifically organic method for controlling these pesky critters. But before you jump to any conclusions upon hearing the word "marigolds," let's take a closer look at this plant group, because there are a number of different kinds of marigolds.

What you probably have in mind when mention is made of this popular bedding plant is:

  1. French marigolds (Tagetes patula), the ones with small flowers 
  2. African marigolds (Tagetes erecta), the ones with large flowers

Both are commonly seen in the colors, orange or yellow. Less frequently encountered is the Signet type (Tagetes tenuifolia). You're even less likely to encounter the mole-repellent plant mentioned in the first sentence of this article. Tagetes minuta simply is not a plant you'll find for sale very often at garden centers, because it's not regarded as an ornamental. Sure, you could search online or through garden catalogs to find it, but there's another difficulty: it's considered an invasive species

Frankly, then, you're better off trying one or both of the two mole-repellent plants I discuss below:

This One Is So Repellent to Them That It's Called "Mole Plant"!

A couple of "living mole repellents" have a decidedly exotic flair: namely, mole plant and castor bean.

That's right: one of these plants has gained such notoriety as a living mole repellent that it is often referred to simply as "mole plant." Also called "caper spurge" (Euphorbia lathyris), this plant is an annual but re-seeds itself readily. It is related to similar plants you may have in your landscaping, such as purple wood spurge.

Mole plant has a striking architecture and is often grown as an ornamental, standing erect and bearing lance-shaped leaves. Its leaves are marked with an exquisite white vein running right down the middle. If you make a cut into a mole plant's stem, a milky sap will ooze out, as when you break the stalk of a milkweed plant. It is apparently the smell of this poisonous, caustic sap that repels the moles.

The final living mole-repellent I'd like to describe is castor bean, also known as castor-oil plant (Ricinus communis). This one's a bit of a no-brainer, since, as I have already mentioned, commercial mole repellent formulas are based on castor oil. Used in the old days as a laxative, there are still many folks out there who can attest to the repellent qualities of castor oil. And it would seem that moles do not like it any better than humans do! A word of caution: castor bean, like mole plant, is a poisonous plant -- neither should be grown around small children.

In temperate climates castor bean is treated as an annual.

It grows quickly and can reach 15' in height, suggesting another use for this plant as well: namely, as a privacy screen for those who don't have time to wait years for a shrub to reach such a height. Castor bean bears huge, star-shaped leaves that make it a very attractive specimen, and thus desirable even on landscapes not plagued by moles.