Pyrethrum, also known as the Chrysanthemum cinerariaefolium, is a natural insecticide derived from the dried flower heads of the pyrethrum daisy. It has been used for centuries as an effective and safe pest control method in agriculture and households.
To grow pyrethrum, it is best to start with seeds indoors 6-8 weeks before the last frost in spring. Once the seedlings have sprouted, they can be transplanted outdoors in a location with full sun and well-draining soil. Pyrethrum is a hardy plant and can withstand temperatures down to -5°C, but it prefers a moderate temperature range of 15-24°C.
Pyrethrum is an excellent companion plant as it repels a wide variety of pests, including mosquitoes, aphids, spider mites, and whiteflies. To use pyrethrum as an insecticide, the dried flower heads are ground into a fine powder and mixed with water to create a spray solution. This solution can be sprayed directly onto plants or used to treat indoor spaces.
It is important to note that while pyrethrum is considered safe for humans and pets, it can also harm beneficial insects such as bees and ladybugs. Therefore, it should be used sparingly and only when necessary.
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Here are some tips to maximize their mosquito repellent properties:
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Plant them in sunny locations: Pyrethrum flowers need full sun to grow well. By planting them in a sunny location, you can help maximize the potency of the mosquito-repelling compounds.
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Plant them in groups: Mosquitoes are attracted to carbon dioxide, which is produced when we exhale. By planting Pyrethrum flowers in groups, you create a larger area of carbon dioxide production, which can help repel mosquitoes more effectively.
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Use the flowers: Once the flowers have bloomed, you can harvest them and use them to make a natural mosquito repellent spray. To do this, boil the flowers in water for several minutes, strain the liquid, and then add a few drops of essential oil (such as lavender or citronella) to enhance the effectiveness. Transfer the liquid to a spray bottle and use it to spray around your home or on your skin.
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Maintain the plants: Keep the Pyrethrum plants healthy by watering them regularly and fertilizing them every few weeks. Healthy plants are more likely to produce effective mosquito-repelling compounds.
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When to Plant Annual and Perennial Pyrethrum Seeds
For Spring planting, it is best carried out within a month or so after the final frost of the winter season. It is important to not plant too early; if seeds are installed prior to a late-season frost, they will be lost for the season and will need to be are-seeded.
For Fall planting, make sure you plant the seeds after the first killing frost to eliminate any chance of germination. Planting in the Fall gives you a jump start on Spring blooms.
Where to Plant Annual and Perennial Pyrethrum Seeds
Though many Pyrethrum do tolerate some filtered shade, and a few actually thrive in it. The vast majority are definitely sun-lovers. Wildflowers will generally sprout in all but the most difficult conditions. This means that pampering your site with fertilizer or rich sod is not usually necessary.
How to Care for Annual and Perennial Pyrethrum
Although Wildflowers are pretty easy to take care of, there are some steps to keep it looking beautiful. Regularly weed to ensure your wildflowers are getting the nutrients they need. Water your plants during dry spells. Deadhead blooms that are spend to encourage new growth.
How to Plant Annual and Perennial Pyrethrum Seeds
Wildflower seeds require light to germinate, so be careful not to cover them when planting.
Clear the area and work the soil as best you can before planting your seeds. Don't panic when some weeds sprout along with the flowers, this will happen when the soil is worked.
We recommend mixing your seeds with sand - 5 parts sand to 1 part seeds. This allows for a more even distribution and also provides a convenient way to mark which portions of the site have been seeded and which have not. For a smaller area, you can hand-broadcast the seeds. For larger areas, we recommend a seed spreader to create a better cast of the seeds.
After the seeds have been sown, lightly compress the seeds into the soil about 1/4" to protect from birds and wind.
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