"When bugs get real bad, can I use poison sprays, at least now and then?" readers of my column sometimes ask. No. They have at least four definite disadvantages.
Used even occasionally, they upset a garden's natural balance, killing not only pests but also bug-eating insects. With praying mantes, ladybugs, lacewings and other insect predators destroyed, insect hordes move in from unsprayed areas, requiring still more lethal doses.
Chemical sprays, falling on soil below treated plants, poison the land, perhaps for years. In time, they seep down to pollute the drinking water supply.
There's also danger from pesticide residues remaining on and in maturing vegetables.
Sprays, inadvertently falling on unprotected faces and arms, may be absorbed by the exposed skin. The poisons are often difficult to remove, even after repeated washing with soap and water.
Desperate natural gardeners sometimes use plant-derived bug-killing sprays, including pyrethrun, rotenone, ryanna and sabadilla. They, too, have disadvantages. While nontoxic to humans, the substances can destroy both friendly bugs and pests. (More on that in a later column.)
Instead of using chemicals to control pests, try these organic building-block substitutes: humus-filled, fertile soil and sufficient insect predators to keep unwanted pests controlled. It works. It has for me and other organic gardeners across the country.
I still use the organic methods I learned from my father. I remember helping him spread that "good old barnyard stuff" on our spacious garden plot. While I knew nothing of the present-day composting art, refuse plowed under produced loamy, friable soil alive with earthworms and the newly harrowed earth felt spongy underfoot.
I knew little then of the advantages of pest-eating insects, but I learned about ladybugs as a child. We chanted a nonsensical rhyme when we saw them:
"Ladybug, Ladybug, fly away home"
I didn't realize the importanceof ladybugs and other predatory insects and the part they play in helping produce abundant vegetables.
Leo Van Meer, author of the book Natural Gardening, has gardened without pesticides for 60 years. He lives in Clearwater.