(Pyrethrum Daisy, Chrysanthemum cinerariifolium = Tanacetum cinerariifolium)
Hardiness: -40 degrees F
Perennial, flowering in the second year and thereafter. Native to western asia and Iran. Flowers white with yellow centers. The buds are dried and ground into insect powder, often used against fleas. The active principles are monoterpenes known as pyrethrins. This is probably the safest insecticide to use in the home, on pets, or around food. Plant prefers full sun and regular garden soil, and produces the highest concentration of pyrethrins when grown in poor soil at altitude or in dry conditions. Plant withstands drought and likes lime. High nitrogen fertilizers encourage leaf growth and discourage flower formation. Sow small seed on surface (light dependent germinator), press in firmly and keep evenly moist and in the light. Seeds germinate best in cool soils. Use pots, flats, or sow directly in the garden in the early spring. Seeds germinate in 2 to 3 weeks. Thin or transplant to 6 inches to 1 foot apart. Flowers 2 to 3 feet tall.