Also known as Tanacetum cinerariifolium. An amazing and beautiful plant grown throughout the world, it is hardy to zone 4 in the USA, makes a wonderful flower bed plant or container plant.
A beautiful daisy that is hardy and blooms throughout the spring and summer. The dried flowers are used to make probably the best natural pesticide available. Simply drying the flowers and making a dust or spray is a great way to control insect pests.
The plant is economically important as a natural source of insecticide. The flowers are pulverized and the active components, called pyrethrins, contained in the seed cases, are extracted and sold in the form of an oleoresin. This is applied as a suspension in water or oil, or as a powder.
Pyrethrum insecticide is one of the most widely used natural insecticides in existence. Pyrethrins work as a contact insecticide, the insect only has to be touched by the substance for it to take effect. When not present in amounts fatal to insects, they still appear to have an insect repellent effect. It will inhibit the biting reflex in female mosquitoes. Crucially, although pyrethrum acts quickly on insect pests, it is relatively non-toxic to humans and warm-blooded animals.
Pyrethrins are not persistent, being biodegradable and also decompose easily on exposure to light. They are considered to be amongst the safest insecticides for use around food.
An on-line resource for making your own pyrethrum at home. It is so easy to do!

Sowing: Sow late winter to late Spring (Feb to May) or Late Summer to Autumn ( August to October) Sow pyrethrum seeds in pots indoors or sow directly where they are to flower in a prepared bed in late spring once all danger of frost has passed. For the best results, choose a planting location that receives full sun and has very well-drained soil of average fertility.

For sowing indoors, sow in pots or trays containing good seed compost. Barely cover the seeds with a fine sprinkling of compost and make sure the compost is kept moist but not wet. Germination usually takes 30 to 60 days at 55°F.
Transplant the indoor seedlings when large enough to handle into pots and grow on. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts. Space 12 inches apart. Water regularly for the first two weeks of growth for container-grown plants to allow them time to become established. Increase watering during times of drought or extreme heat.