Purple coneflowers, a member of the Echinacea family, are perennial bloomers in the flower garden. Coneflowers offer long-lasting color, blooming from early summer until fall. They can reach up to 4 feet tall, though 2 feet is a more common height. Coneflowers tolerate most soil conditions, require minimal maintenance and are resistant to many pests. They also attract butterflies to the garden, making them a suitable addition to butterfly gardens. Start coneflower seeds directly in the garden in spring once frost danger is past.
Apply 1 inch of compost to a garden bed that receives full sun. Use the hoe to work the compost into the top 6 inches of soil in the bed.
Sprinkle coneflower seeds onto the soil surface. Sow thinly, placing approximately one seed per each 6-inch square of bed.
Cover the seeds with 1/8 inch of soil once they sprout. Mist the bed lightly with water to moisten it.
Thin the seedlings once they are 4 inches tall. Pluck out the extra seedlings so that the coneflowers are spaced approximately 18 inches apart in all directions.
Water purple coneflowers once a week. Moisten the soil to a 6-inch depth at each irrigation. Apply 2 inches of mulch over the bed to help preserve the moisture in the soil.
Fertilize coneflowers each spring when they begin growing again. Apply 1 lb. of 12-6-6, slow-release fertilizer per every 100 square feet of bed.