Creative Ways to Fight Pests

By Julie Marshall
Scripps Howard News Service

Kneeling in her garden, Greta Gottlieb peeks under a slab of flagstone. A worm wiggles out from the dark, moist soil — good luck, because worms aerate the soil, the Boulder, Colo., gardener says.

Gottlieb lifts a plant saucer. Darn, just a roly-poly. She turns over tender young cabbage leaves and grunts in disgust at freshly eaten holes.

The hunt is on for garden slugs, and Gottlieb is armed and ready with a spray bottle filled with white vinegar. "When you spray slugs, they will turn this solid white color, like when you cook raw fish," she says. "They are definitely dead."

With no slugs in sight, Gottlieb turns to spraying dandelions. It really works, says Gottlieb, a self-described fanatic when it comes to organic pesticides. Don't even say the word "chemical" or she'll make a face like she's sunk her teeth into a lemon.

For Gottlieb and many gardeners who ban synthetic pesticides, the choice is about health. A report in the journal Bioscience says 1 percent of chemical pesticides reaches its intended target; the majority of chemicals are spread to the soil, water and air.

But giving up chemicals doesn't mean resigning yourself to a yard full of weeds and a garden full of slugs and bugs.

Home remedies comprised of natural products that kill weeds, destroy pesky bugs or fight plant disease abound. Gardeners who don't want to mess with toxic chemicals on their food or near their kids and pets are turning to experts and garden lore to find concoctions that protect new spring growth. Hot peppers soaked in water, for instance, is a known deterrent to chewing bugs. The hotter the jalapeno, the better.

Another signature weapon in the organic pesticide arsenal is the use of "good" bugs to combat the "bad." Ladybugs, for instance, are known enemies to the aphid — a sucking bug that destroys tender leaves. Flowering plants, peas, beans, clover and alfalfa attract ladybugs.

Finally, when you hear about organic gardening, the buzzword these days is "companion gardening." Studies show that particular herbs or flowers can repel insects harmful to vegetable plantings. Onions, for instance, planted next to carrots in a ratio of 4-to-1, can help ward off the carrot fly whose larva attacks the roots of young plants. Leeks, as well as herbs such as rosemary and sage, also act as fly repellents.

Garden folklore tells us that onions planted near roses prevents disease, says Chad Brunette, a senior horticulturist at Denver Botanic Gardens. Natural oils in the leaves of thyme, rosemary and other pungent herbs, repel destructive insects.

"And let loose some ladybugs in the garden," Brunette adds. One ladybug can eat 200 aphids a day.

David Daum, an avid organic gardener in Boulder, has a few home remedies up his sleeve as well. "Try nicotine," he says. Soak cigarettes in water, drain and you have a spray that kills aphids and most chewing insects.

In the end, you've got to be willing to have a few "bad" bugs in the yard, Daum says, and accept that every leaf may not be perfect. "Nature works, but the problem is people get carried away, and spray all the bad with the good."

The gardening industry has heard the public's cry for something other than synthetic chemicals and come up with "organic" pesticides made from natural products that are low in toxicity.

An insecticide soap called Safer is popular for killing aphids and spider mites, says Connie Smith, manager of the Sturtz & Copeland florist shop in Boulder. Her greenhouse sells a lot of Ultra-fine oil made to smother bugs.

Bacillus thuringiensis, commonly called Bt, is made of bacterial spores that produce an insect-toxin protein and is useful for anything in the caterpillar family, from cabbage worms to tomato hornworms, Smith says. The protein kills by causing paralysis of the mouth and gut.

And Smith's home remedies? A potion of water, baking soda and two drops of dish soap cures mildew on roses, cucumber and squash, she says.

She's excited about a new product called Sluggo, made with iron phosphate, that kills slugs and turns into a non-toxic soil nutrient.

Daum adds to the list of commercially available biological pesticides. Pyrethrum, made from the flowerheads of mums is good for aphids. Neem, named after a tree in India, repels whiteflies and a wide range of bugs.

Most organic gardeners warn, however, that just because you use a less toxic spray doesn't mean it's safe to use more of it. Some argue that commercially manufactured pesticides, even organic ones, should only be used as a last resort.

(Contact Julie Marshall of the Daily Camera in Boulder, Co., at www.dailycamera.com.)