Is organic always best?

Jeff Gillman believes in organic gardening. But he also believes that not everything organic is safe.

While he doesn't like pesticides, there are times he thinks chemical or synthetic products are better than organic ones.

Gillman's book, "The Truth about Organic Gardening" (Timber Press, $12.95), tries to help gardeners sort out what's safe, effective and reasonably priced.

Nicotine is natural but toxic, for example, while vinegar is safe unless you get it in your eyes, but it doesn't kill a weed's roots.

Gillman likes the chemical glysophate -- active in a herbicide called Roundup -- for clearing a piece of land before planting.

"The word organic does not make something safe and it really bothers me when people think it does," the author said in a phone interview.

"Organic pesticides are still pesticides and in many cases can be more dangerous than the chemical ones."

The associate professor in horticultural science at the University of Minnesota, believes that the fundamentals of organic gardening -- composting and mulching -- are extremely important.

Chasing pests

Organic options

Citrus oil -- Don't use this pesticide on plants, it can damage them. Strong mixtures could injure eyes and even skin. Try on ants and ant mounds.

Rotenone -- Derived from plants, but Gillman really fears it. Rotenone is known as a fish poison, and low doses have been shown to give rats Parkinson's diseaselike symptoms.

Ladybugs -- They eat aphids, caterpillars, scale and mites voraciously. However, they don't stay put, so it's fine to buy some for an indoor garden, but they fly away home when outdoors

Better choices

Traps, insect-resistant plants and efforts to keep beneficial insects happy and alive in your garden are worth the effort, said Gilman. He hates insecticides and says if you're going to use one, choose the safest you can find -- something either organic or chemical that disintegrates quickly and fits your pest. But follow the directions.

Enriching soil

Organic option

Manure -- Compost is the darling of anyone who gardens, but organic material like manure must be composted or broken down by microorganisms. Otherwise, you could face harmful bacteria like the dreaded E. coli. This is more dangerous the closer to harvest it is used.

Better choice

If you add enough nutrients to the soil before you plant, you won't need fertilizer during the season. Synthetic fertilizers are really made from natural products and are cheap and effective. But some object to the energy and mining required to produce them.

Fighting disease

Organic option

Copper compounds -- While copper compounds effectively control plant diseases and fungis, they are very damaging to aquatic environments and dangerous to people if ingested.

Better choices

Choose disease-resistant plants and take care of your plants, especially removing diseased plants and fresh vegetable waste. Sulphur, an organic fungicide, and chlororthalonil, a synthetic one, are recommended if you're sure it's a fungus.

Controlling weeds

Organic options

Corn gluten meal -- the only organic herbicide that works on weeds before they come up. Even Gillman thinks it's safe, and it fertilizes as it kills weeds, but it is more expensive than synthetic herbicides and might take years to work.

Flaming -- Burning is the classic way to rid Midwest prairies of unwanted plants. The drawbacks are obvious -- you might burn a plant or even a building that you had wanted to keep.

Salt -- Salt kills weeds, and it's safe if you're growing celery or asparagus or other resistant crops. However, it is fatal to many plants.

Vinegar -- The acid kills young weeds without strong root systems, but to get the roots you are going to need many applications. Higher concentrations can hurt your eyes.

Better choice

While Gillman thinks the best method for gardeners is hand weeding, he uses glyphosate -- sold as Roundup. For example, he likes it for preparing a large piece of ground to start a garden.

Keep it out of bodies of water because it is made with oil and soap that will kill aquatic animals. He also uses chemicals classified as pre-emergent that kill weeds as they come out of the seed.

Evaluating pesticides

The Environmental Impact Quotent is a way to look at both organic and synthetic pesticides.

It tells relative dangers to humans and the environment.

The system was developed at Cornell University in the early 1990s.

The information is available at www.nysipm.cornell.edu/publications/eiq/.

EIQs figure the risk to the person who mixes and applies the poison, the consumer of the product and the environment.

A score of 10 is low and 100 considered more dangerous.

While EIQs are not perfect, and Jeff Gillman disagrees with some, the author calls them a useful tool.

"I am surprised EIQs are not more widely distributed," he said.

Doses, concentrations and frequency all seriously affect whether something is a poison or not.

For example, a sprinkle of salt is not poisonous, but two tablespoons could be toxic to a 1-year-old.

EIQs are not on product labels, those only indicate whether the item is toxic to humans and don't deal with the environmental effects, Gillman said.