Prairie Lawn Critters and Pests

MOLES AND GOPHERS

Conventional practice is to eliminate moles by poisoning or trapping them, and then to rely on insecticides to eradicate the grubs once kept under control by the moles. This is overkill, and there are friendlier ways to deal with the problem.

You can spray your lawn with BT (bacillus thuringensis), a bacterium that kills off caterpillars of all varieties but harms nothing else. With no grubs to hunt, moles will soon move on. You can also infect your soil with milky spore disease, which kills Japanese beetle grubs and some others. For this to work, however, you have to convince all your neighbors to do it too, otherwise the beetles will fly in from their yards to decimate your roses.

As is so often true, it's best to let nature take its course: Let the moles work for you. They'll happily feast on all the grubs you don't want in your lawn, such as the sod web worms that girdle corn seedlings and create dry patches in your lawn by eating the grass' tender stems. Moles will also rid your turf of the cutworms that snip off your laboriously raised tomato and broccoli seedlings, as well as the larvae of Japanese beetles and other pests that will attack your flowers and vegetable plants in their voracious adult stage.

The problem, of course, is the network of lumpy nests and tunnels moles leave in their wake. A healthy mole can burrow ten to 15 feet an hour, and in a solitary night a couple of moles can make a real mess of your lawn and garden. Moles seldom harm garden plants, but their rifling of the soil will expose grass and other plant roots to air, which will cause them to dry out and die. The solution: First thing in the morning, give the lawn a good soak and smooth it over with a lawn roller. The sod will reroot just fine.

A more aggressive measure is to acquire and train a mole hound - any digging breed of hunting dog will do. Dachshunds, bred to hunt ferrets, and beagles, trained to flush out rabbit warrens, are ideal. Our best mole hounds have been German shepherds. Though not great diggers by nature, shepherds trace along tunnels to where the moles are active and flip them out with a swipe of the paw.

There's a variety of murderous mole traps you can set, and you can also fill the tunnels with water or vehicle exhaust. It is more humane, however, to repel rather than murder moles. The most benign repellent is sound. Wind-powered lawn ornaments send a clacking sound into the ground that is reputed to drive moles away. You can find the finished device or plans to make one yourself advertised in woodcraft and garden supply magazines and catalogs.

An old-fashioned yet effective anti-mole measure is to plant castor beans around the margins of your lawn. Especially if started indoors in late winter, a row of castor can grow into an effective screen hedge. The entire plant is mildly toxic and has been proven in both common practice and scientific tests to repel moles. However, after making sprays of vivid red, spikey flowers, the plant produces large, brown, lima-shaped beans that are highly toxic to small children, pets and livestock. The seed pulp contains castor oil, a purgative, plus a toxin called ricin that is so poisonous it has been used as an organic pest control and is suspected as an agent of biological warfare. It is best not to grow castor anywhere children or domestic animals can get to it. And, to prevent grief, never let the plants make seed; nip off the large flowering spikes as soon as they appear.

You can buy liquid mole repellent made from castor oil (which cannot mix with water-based ricin, so the repellent contains none of the poison) in hardware and garden supply outlets or on the Internet: elixir of castor bean in spray-on-the-lawn concentrate is available from www.deerbusters.com .

Or, you can make your own castor-oil concentrate by mixing six ounces of castor oil (from any drugstore) and two tablespoons of detergent with one gallon of water. Apply it to your lawn using a hose spray-mixer, combine at a rate of one cup castor oil concentrate to one gallon of water. Water lawn thoroughly so the mix gets down to mole level - about six inches below ground.

The only foolproof, nontoxic gopher repellents we know of are onions, garlic, dahlias and other bulbs, tubers and succulent-rooted plants. Grow them inside loosely closed cylinders rolled from 1' x 4' rectangles of 1/2"-grid galvanized fence-wire. This method makes harvesting easy; once top-growth has died down, just dig them up and shake soil from inside the cages, crop and all. You can hang the roots, still inside cages, from barn rafters to dry. Unhook and open cages to remove and clean roots for winter storage. Open cages will retain their curve and store stacked in threes and fours out of the way, hanging on hooks or big nails tapped into the barn wall.

You could also try a battery-powered ground spike from Lentek ($20) that emits ultrasonic vibes at a relatively low vibration. Ground-burrowing mammals will tend to avoid it. This ground spike will cover 7,500 square feet, and is sold through garden magazine ads or at http://www.repelandkill.com/repelgophers.shtml .

FIRE ANTS

The red fire ant was accidentally imported to Alabama 70 years ago and has been spreading throughout the deep South ever since. Colonies build 12-to 18-inch-high mounds in lawns or gardens, or they'll make nests in house or outbuilding walls. Aggressive if disturbed, fire ants advance in large numbers, grab an intruder with their jaws and inject a painful sting. Small children and adults allergic to insect venom may be in real danger.

If the problem is severe, if they've moved into your house or driven your children from the play area of your lawn, you may need professional help. An exterminator can apply some of the more virulent poisons without harming nontarget species.

Organic purists can reduce colony numbers by flushing an ant mound with liminoids - the bitter chemicals found in citrus fruit rinds. To do this, finely grind lemon and orange peels in a food processor, and heat up some orange or lemon juice. Quickly shove the small end of a large metal funnel into the mound, dump the pulp into the funnel and pour the hot juice through it several times. Renew the pulp periodically.

For do-it-yourself control of serious infestations in either house or yard, the natural insecticides pyrethrum and rotenone are available in injector-tipped applicators. Unfortunately, these are only mildly effective. We recommend that you consider nonpoisonous baits containing Hydramethylnon (Amdro®) that gives the insects a fatal tummy ache. Or, try fenoxycarb (Award Brand of Logic®) and avermectin (Ascend®), which act as insectgrowth regulators. Both take a while to work, but worker ants will take the baits down into the nest and eventually all the egg-laying queens will be killed. The effects are residual, and will even work against a new colony that tries to move into an old nest.

CHIGGERS

Chiggers are the microscopic larvae of the tiny red harvest mite, found in lawns and meadows over much of the continent. They lurk on tips of grasses to hitch a ride on any passing warm-blooded creature. They prefer rodents, dogs or deer, but will snag a passing human and migrate to anyplace clothing fits snugly - sock tops, waist bands, legs and the waist, where a baby's diaper fits snugly. A chigger's bite elicits an allergic reaction in many and will raise a large, red, itching welt that can last for days. Scratching just makes it worse. Your best offense is a strong defense.

*Keep the baby in a playpen or on a blanket rather than out in the grass. An immediate warm bath will remove chiggers that haven't yet dug in.

*Keep grass short and dry to discourage female mites from laying eggs. They will seek out more favorable conditions elsewhere.

*Apply repellents containing DEET to socks and other tight clothing spots.

*Pyrethrum - applied liberally to a freshly mowed lawn in April or early May - will control populations in limited areas.

If, despite protective measures, you still get chewed upon by chiggers, an age-appropriate antihistamine medication taken internally or a topical ointment applied liberally can help to reduce the miserable itching.