An Herb to Honor Veterans
War time technology often yields things of great use for peace time. Such is the case for the herb pyrethrum (chrysanthemum cinerariaefolium). The legend has it that Prussian soldiers camped overnight in a field of flowers and awoke with the welcome realization that the persistent infestations of body lice were all gone from their clothes. Thus began a brisk trade at worldwide pharmacies in dried pyrethrum flowers as insect powder. It has been a soldier’s friend and a military standard issue supply ever since.
By 1913 its supply source from Dalmatia (now Yugoslavia) was cut off by another war. Japan then became the major provider of a substance that was used effectively against all manner of insects in the home and around barns and farms. Simple extracts of the pyrethrum flowers were made with kerosene to create a liquid that could be sprayed. In the 1920s and 1930s it was exhaustively studied for its chemical constituents and was the subject of scientific books and reports.
In our current search for safe and effective products to use in the garden and around the house, new interest has focused on this simple chrysanthemum flower. The preparation and refining methods have progressed to remove waxes, oils and allergenic properties that can be irritating to human skin. And several anti-oxidant stabilizers have been found to keep the ground powders from degrading before use. One of the most effective, and expensive, is one called piperonyl butoxide (PBO). Preservatives are necessary since the raw material tends to release all of its active esters quickly and degrades rapidly in sunlight. If you cannot have a constant supply of fresh flowers, then you need a product with a good shelf life.
This insecticide has long been listed as non-toxic to humans and animals, while deadly to lice, mosquitos, ants, and for garden pests. It is currently grown commercially in Kenya, Ecuador, New Zealand, Tasmania and even Norfolk, England. It is highly prized and in short supply, making it expensive. It has not proven possible to create a synthetic version. (I love it when that happens.)
This chrysanthemum will grow well in San Diego most of the year and make a pleasant addition to the garden, with masses of pale flowers the size of a quarter. You can harvest your own flowers to dry and store in amber glass jars. When the ants invade, you can grind some flowers to powder and sprinkle it on their trails. It will act immediately. But it will need to be re-applied each day, since its “knock down power” on insects dissipates in a few hours. If you shop in oriental grocery stores, you can ask for an insecticidal “chalk” that is used, quite literally, to draw a line with insects, making it useful to create a protective circle around a pet’s food dish.
Many thanks to our veterans for all of their dedicated service and to those early foot soldiers who noticed and celebrated the “flower power” of a simple herb that brought them some personal peace, Pyrethrum. They gave us this as an enduring gift that is uniquely suited to our modern times: a safe insecticide to which bugs do not develop a resistance.
Category: Health & Fitness
