“Organic Pesticide is not an Oxymoron,” a seminar at the Maine Landscape and Nursery Association trade show this winter, drew me in like a hungry honeybee to the first dandelions of spring. And now that early spring is just about here, that talk is on my mind again.

Pesticides – especially synthetic pesticides – are a hot topic. In November, Ogunquit banned the use of synthetic pesticides and fertilizers on privately owned land, the first community in Maine to do so. Several communities have banned them on public and/or school land.

In addition, legislation has been introduced at the state level that would place a moratorium on the use of neonicotinoid pesticides, which some blame for colony collapse disorder in honeybees.

But during his seminar, Gary Fish of the Maine Board of Pesticides Control had a different perspective: “Synthetic does not mean highly toxic,” he said, “and organic and natural does not mean safe.”

In an email exchange last week, Fish expanded on that statement, citing research from the University of California, Berkeley, that has shown that natural pesticides cause cancer in rats just as frequently as human-made pesticides.

Fish’s seminar was directed at professional pesticide applicators and farmers who, under a law that takes effect on April 1, must get a special pesticide license if they sell more than $1,000 worth of food per year.

Much of what he said, however, would be helpful for backyard gardeners, too, attempting to keep Japanese beetles or spotted-wing drosophila from chowing down on their raspberries or lily leaf beetles from leveling their Stargazers.

Of the 857 million pounds of pesticides sold nationally in 2007, the most recent year for which there are statistics, 8 percent – or 69 million pounds – were applied by homeowners, who buy and apply them with no instruction at all despite the potential hazards. (The remaining pesticides were applied by professional applicators, the vast majority – 80 percent – for agriculture.)

The most important thing that homeowners – and professionals – can do is to read the label of the pesticide they are using.

Fish relayed a story he heard from a pesticide toxicologist about a woman who was growing vegetables to serve at her wedding. She applied two bags of an organophosphate insecticide, enough for 10,000 square feet, on her 500-square-foot vegetable garden. The label said harvesting should take place 30 days after pesticide application, but the wedding was just 10 days after application.

“Of course, we suggested that she not harvest the vegetables,” Fish said, “nor serve them at the wedding.”

Then there was the organic vegetable grower who used the hydrogen peroxide pesticide Oxidate, and got some on his fingers when he recapped the bottle, Fish said. Unthinkingly, he wiped his eyes, and he suffered severe damage to his cornea. The label clearly stated: “DANGER: CORROSIVE. Causes irreversible eye damage.”

Fish said that surveys taken a few years ago at the Portland Flower Show demonstrated that many people do not understand what a pesticide is. By definition, a pesticide is any natural or synthetic product that kills or repels pests, including insecticides for insects, fungicides for fungus, herbicides for weeds and a lot of other “cides,” he said.

Licensed pesticide applicators know, and homeowners likely do not, the biology of how pesticides work and the principles of integrated pest management (IPM); the latter is a system that encourages the least harmful strategies – such as prevention; sanitation; and cultural, mechanical and biological controls – before resorting to chemicals. The professionals also learn how to keep themselves safe, avoid contamination of nearby bodies of water, and avoid killing species they don’t want to kill, such as bees.

Another thing that especially interested me are the items that seem safe to eat, such as peppermint and clove oils. Although often listed as “natural” pesticides, they can cause problems if misused. Even though the federal Environmental Protection Agency has exempted such essential oils from pesticide requirements, in Maine they remain on the state’s controlled lists.

What all of this says to me is that homeowners should consider carefully before using any pesticide. The motto for Integrated Pest Management is “Think first, spray last,” and that makes sense.

I have met and talked with people who want me to identify an insect in their garden. First, I’m not a “bug guy,” but second, they don’t bring the insect with them. When I point out how difficult identification is without the bug, they usually say, “I’ve got a bottle of stuff in my garage, I can use that and it will probably kill them.”

When I ask what’s in the bottle, sometimes they know, but usually they don’t. And I’ve never met a homeowner who knew both what was in the bottle and what the list on the label said it worked against. Sometimes, I think home gardeners should be required to take the same licensing tests that the state requires of applicators.

Here’s a better way: If you can dump the Japanese and/or lily leaf beetles into a jar of soapy water, you aren’t in any more risk than you would be from washing your hands – even though soap probably meets the technical definition of a pesticide. If you don’t have a 5-year-old around (they love this stuff), wear your gardening gloves to gather the bugs and use a jar from your recycling bin. Put the lid on for a day, and it should kill the bugs. Repeat daily.

Do some research to figure what is actually bothering your plants. The state has a great website, gotpests.org, that can help you identify your pest and, once you have, will tell you the least harmful ways to control it.

That’s much better than spraying with an insecticide that kills everything – including bees and other beneficial insects that you actually want in your garden.

I am repeating myself, but this bears repeating. If you do use a pesticide, remember the most important rule: Read the label and follow its instructions.

Tom Atwell has been writing the Maine Gardener column since 2004. He is a freelance writer gardening in Cape Elizabeth and can be contacted at 767-2297 or at [email protected]

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