How to Get Rid of Gophers, Moles and Armadillos
Learn how to drive off unwanted underground garden guests with these expert tips.
There are a number of ways to control underground pests - from trapping and flooding to poison - but master gardener Paul James prefers using a granular form of his favorite repellent: castor oil. This relatively new product does an excellent job of controlling moles, gophers and even armadillos.
Natural Gopher Control 05:32
So just how do you know whether you have moles or gophers? For one thing, moles don't eat plants. They primarily eat grubs and earthworms, and they leave telltale tunnels or shallow, surface ridges as well as circular mounds of dirt above ground with holes in the center.
On the other hand, gophers eat plants, and their tunnels are rarely visible. Gopher mounds are fan-shaped with a hole off to one side.
"Frankly, I don't mind moles that much," Paul says. "The tunnels they create can be a nuisance, but in the process of tunneling, they help aerate the soil. Besides, I don't have that many moles because I use a combination of milky spore bacteria and beneficial nematodes to destroy the grubs that moles feed on."
But gophers are another story, and at Paul's place, they've been having a feeding frenzy. "While I was on vacation recently, they ate more than 150 of the hostas in a bed. And aside from the economic damage, which I conservatively estimate at between $2,000 and $3,000, the gophers destroyed what I considered a really beautiful garden bed."
Red Spider Mites
The tiny mites live under leaves and suck sap, causing yellow mottling. Fine webs are sometimes visible. Raise humidity and use a biological control under glass. Otherwise try organic sprays.
These microscopic mites suck sap and cause abnormal growths. These include raised pimples or clumps of matted hairs on leaves, or enlarged buds. Most are harmless and can be tolerated.
Leaf Miner Damage
The larvae of various flies, moths, sawflies and beetles feed within the leaves, creating discolored blotches or surface trails. Most leaf miner damage is relatively harmless and can be left untreated.
To avoid maggots in apples, spray emerging caterpillars twice using bifenthrin, starting in midsummer. Also hang pheromone traps in late spring to catch male moths and prevent them from mating.
In spring, the leaves of fruit trees are webbed together and hide green caterpillars inside. Holes are visible when leaves expand. Apply sticky traps to capture adult moths.
Tiny blister or shell-like bumps on leaf backs result in poor growth. Other symptoms are sticky excretions and sooty mold on evergreens. Wash off mold, and spray with horticultural oil.
Under glass, hang yellow sticky pads to trap the tiny white flying adults, which suck sap from plants; use a biological control (Encarsia wasp) on larvae or spray with organic chemical controls.
Both the adults and larvae eat holes in the leaves, mainly on Viburnum tinus and V. opulus; this can slow growth and looks unsightly. Spray badly affected plants in spring with bifenthrin or thiacloprid.
This tiny black sap-sucker, known as "thunder fly," causes white patches on the petals and leaves of indoor plants, and also peas, leeks, onions and gladioli. Use biological controls.
Vine Weevil Larvae
Small cream grubs with a brown head feed on plant roots, especially those growing in containers or with fleshy roots. This can cause plants to suddenly collapse.
Adult Vine Weevil
The adult beetle is nocturnal, flightless and makes notches in leaves. Use a biological control (nematodes).
Cabbage White Caterpillars
These voracious eaters decimate brassicas and nasturtiums. Rub off egg clusters and pick off any caterpillars you find.
The tomato moth damages fruits. Pick off any caterpillars you find.
The caterpillar-like larvae devour the foliage on plants such as roses, gooseberries and Solomon's seal. Leaf rolling is usually the first sign of sawflies. Pick caterpillars off by hand or spray with bifenthrin or pyrethrum.
Woolly Beech Aphid
Seen in early summer, these white fluffy aphids coat shoots and the undersides of leaves. They suck sap and excrete honeydew that supports black sooty mold.
Mostly beneficial, earwigs are nocturnal and feed on dahlia, chrysanthemum and clematis flowers. Lure them into upturned flower pots filled with straw and release them elsewhere.
So, to get rid of the unwanted gophers, James uses the castor oil granules. Keep in mind that castor oil products don't actually harm moles or gophers, they simply send them scurrying elsewhere. In fact, you can dictate the direction you want them to go. Using a spreader, Paul evenly spreads the granules over an area of his yard where the damage has been particularly bad. With this product, the coverage rate is a mere one pound per 1,000 square feet, which means a little bit goes a long way. But it's difficult to judge how much, or in this case, how little you've put down.
You can water the granules in if you like, or you can just wait on the rain to do the job for you. Either way, the granules will slowly begin to dissolve and release the scent that repels both moles and gophers. "This is an all-natural product containing nothing more than castor oil, soap and corncob granules, which are actually good for the lawn," Paul says.
If you're treating a large area, simply broadcast the granules all over your property, including your lawn and garden beds, directing the moles and gophers to the nearest exit point of your property." To force the pests in a specific direction, apply the granules to one-third the area to be treated, beginning with the area farthest from the ultimate exit point. And within hours, especially if you water the area well, the gophers will begin moving in that direction. A day or two later, apply more granules to the next section, and a day or two after that, apply additional granules to the final section.
The trick to using any granular product is getting even coverage. Paul suggests trying one of three methods. One way is to simply broadcast the granules lightly but as evenly as possible by hand. The second is to use a hand-held spreader set to the lowest application rate. The third method is to use a conventional broadcast spreader set to the lowest application rate.
Some other commonly used techniques include setting traps; whether live or lethal, they work pretty well if you set them properly. Flooding the tunnels with water or fumigating them by attaching a hose to the exhaust of a lawn mower can also be effective.
"Poison peanuts and smoke bombs don't work well," Paul says, "and their use has been banned in several states." But milky spore bacteria and beneficial nematodes are especially beneficial eliminating moles because both all-natural products destroy the grubs they feed on.