I’ve sometimes had fun tormenting my organic food-loving friends by asking them what they were doing to avoid the huge variety of “natural pesticides” which permeate the plant kingdom. Some get genuinely frightened when I explain to them the “natural insecticides” and “natural herbicides” which are bio-weapons in the biochemical warfare of nature all around us.
When I was young growing up on a farm I knew neighboring gardeners who would grow flowers like chrysanthemums and marigolds among their vegetable garden rows in order to take advantage of the pyrethrins (to curb insect pests.)
And wherever there were black walnut trees one would usually find a lot of bare soil around them because their roots secrete herbicide poisons to decrease competition. In fact, people who grew tomatoes hated black walnut trees because the roots would extend quite a distance and destroy the tomato crop. (On the other hand, some people loved their black walnut trees because those were suitable for veneer table tops and cabinets. Our walnut trees had too many knots so they would sell for perhaps $50 to $100 wholesale back in the 1960’s—but I knew of a farmer who had ideal trees along a river bank and just one of his trees sold to a timber-buyer for $30,000. Some of his trees produced near perfect thin-veneer of the ideal tree-ring density for very expensive furniture, as in corporate boardroom conference tables which were twenty feet long but made from one continuous layer of veneer walnut.)
Some people are at least aware that nicotine is a “natural insecticide.” Not as many realize that the caffeine in coffee and tea leaves is also a pesticide for protecting the plants from leaf-chewing insects. So I’ve sometimes asked people, “Are you sure that you want to drink so much of that insecticide-tainted dark liquid?”