How to Grow Pyrethrum Flowers

Select a location that contains well-drained soil and receives at least six hours of full sun throughout the day. The site should be away from artificial nighttime lighting, such as street lamps and porch lights.

Begin breaking up the soil with a pitchfork or spade in the early months of spring when frost is no longer a worry. Working the soil to a 12-inch depth creates a loose planting medium that allows pyrethrum roots plenty of room for expansion.

Add 4 inches of compost to the broken soil, turning the soil over with the pitchfork until evenly distributed. Peat moss, manure and fallen leaves make perfect compost for pyrethrum planting.

Dig holes in the planting plot large enough to accommodate the roots of the pyrethrum plants. Space the planting holes a minimum of 18 inches apart to give the foliage of the plants plenty of space to grow. 24-inch spacing will allow for maximum growth with some space in between plants.

Tip the pyrethrum plants and remove them from their nursery pots. Set one plant in each of the prepared holes, packing the soil around each stem. All foliage should be above the soil line during planting.

Water the pyrethrum with a watering can or outdoor garden hose. Dampen the soil to a depth of 1 inch, maintaining the same level of moisture throughout the growing season. Weekly watering in combination with normal rainfall should suffice.

Feed the pyrethrum flowers a water-soluble fertilizer. Monthly fertilization after the plants show signs of new growth is preferable. Follow the instructions printed on the fertilizer's label if you are unsure of how or when to apply the fertilizer.