The pyrethrum daisy, better known as a chrysanthemum, has long been known to have insecticidal properties. The flowers naturally repel a number of pests, from fleas to lice to mosquitoes. While it is certainly a beautiful and colorful addition to any garden, the pyrethrum daisy is also one of nature's strongest, most effective insect repellents.
The use of pyrethrum as a natural bug repellent dates back hundreds of years. First used in the Middle East, pyrethrum was frequently dried and traded on the Silk Route. As the flower's popularity grew, it moved into Europe, where it continued to be used for its pesticidal properties. By the time World War II began, pyrethrum daisies were harvested as a natural pest repellent for the allied forces.
Pyrethrum is harvested from the seeds in the center of the pyrethrum daisy plant. The oil is found on the seed cases, which are first dried and then pelletized and crushed. Afterward, oleoresins are extracted, which contain pyrethrin, the active pesticidal ingredient found in pyrethrum.
How it Works
Pyrethrin is a naturally occurring neurotoxin that can affect the nervous system of all insects at its strongest concentration. Pyrethrum causes the insects to lose control, paralyzing and sometimes killing them. When the substance is less concentrated, it effectively repels mosquitoes, mites, ticks, fleas, lice, ants and more.
Advances in technology have allowed us to expand on the use of pyrethrum for widespread mosquito control. Pyrethrin is often combined with other chemicals to create a synergized pyrethrin, which intensifies the pescticidal properties and has a more lasting effect than pyrethrin alone.
Growing Your Own
Pyrethrum daisies are relatively easy to grow, whether you choose to start the seeds indoors or sow them outdoors. The flowers grow up to 24 inches tall, with white petals and yellow centers. The most important consideration when growing your own pyrethrum daisies is the amount of sun and warmth the plants will receive. You can maximize the insecticidal value of these flowers by planting them in the warmest, sunniest spot in the garden.
When planting in your garden, this plant can be extremely effective at keeping away the pests. However, one consideration to keep in mind is whether your plants actually need bugs for pollination; planting pyrethrum daisies too close to vegetables and flowers may actually prevent pollination.
- Photo Credit Daisy, Daisy. image by RedRocket from Fotolia.com
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