Pyrethrum (Chrysanthemum cinerariaefolium), also called the painted daisy, is a perennial flowering plant with foliage that resembles a fern and flowers that look like daisies. The pyrethrum’s flowers are used to make insecticides with low toxicity, according to North Carolina State University Extension. Pyrethrum thrives in full sun in U.S. Department of Agriculture plant hardiness zones 3 to 7. Sow your pyrethrum seeds indoors in February.
Fill the seeding tray with seed starting mix. Press the mix into the tray and water it until the soil is saturated and water runs from the bottom of the tray. Allow it to drain completely.
Place the seeds on the surface of the soil and cover with a 1/4-inch layer of perlite.
Place the tray in a plastic bag and seal it. Place the bagged tray in an area that receives sunlight. The seeds should sprout within 30 to 60 days, at which time the tray should be removed from the bag.
Water the seedlings just enough to keep the soil moist.
Transplant the pyrethrum seedlings into 3-inch pots when they have their third set of leaves. Place the pots in a sunny area and keep the soil moist.
Plant the seedlings into the garden when they reach 6 inches in height. Ordinary garden soil is sufficient and the planting holes should be dug to the same depth and twice the width of the planting pot.
Allow the soil to dry to within 2 inches of the surface prior to watering.
Pinch the tips off of new branches while the plant is actively growing. This will encourage it to produce new branches.
Cut the pyrethrum back 2 inches after the blooming period. Give it a dose of fertilizer and the plant should bloom again.