About Flat-topped Aster: This early-blooming aster provides nectar for Pearl Crescent and Silvery Checkerspot butterflies, as a host plant in their life cycle. In the wild, it grows in moist, sandy areas or woodland. Originally from the Greek language, “aster” means “star.” At one time, asters were called starworts, frost flowers, or Michaelmas daisies; in spite of their daisy-like petals, asters are actually diminutive members of the sunflower family. In the language of flowers, these starry blossoms symbolize elegance or daintiness. They make a traditional gift for birthdays in the month of September, or for 20th wedding anniversaries.
Flat-topped Aster Germination: Direct sow the seed in late fall, planting it just under the surface and watering it once. If direct sown in the spring, the seed must be stratified first by mixing it with moist sand and stored in the refrigerator for 60 days. To start the stratified seed indoors, sow it in a flat; keep the soil evenly moist and at a temperature of 65-70 degrees F until germination, which should take place within 14-20 days. Transplant the seedlings after the last frost of spring, placing them 18-24” apart. This plant prefers full sun and wet to medium soil, and also grows well in clay or sandy soil.
Growing Flat-topped Aster Seeds: These plants tolerate some drought, but will need occasional watering in dry weather; young plants especially need moisture to become established. The lower leaves may wither in dry weather. Keep weeds under control, since this plant does not like competition. Mature plants will benefit from division after two or three years of growth. These asters will slowly reseed themselves and spread by rhizomes, forming a colony over time if volunteer plants are not removed. Cut the stalks down to the ground at the end of the growing season for easier growth in the spring. The flowers attract numerous bees and butterflies, providing a valuable source of nectar in late fall.
Harvesting Flat-topped Aster: Asters make lovely cut flowers. Cut the stems long, choosing flowers that have just opened.
Saving Flat-topped Aster Seeds: After flowering, the plant will produce seed heads containing small clusters of seed with white fluff. Since sparrows and goldfinches love to eat the seed, harvest it promptly to avoid loss. Cut the mature seed heads, or shake them into a container to remove the seed material. Clean the seed as well as possible, then store it in a cool, dry place.
Detailed Flat-topped Aster Info: Origin: US Native Other Common Names: Tall Flat-topped White Aster, Parasol Aster, Cornel-Leaf Whitetop Duration: Perennial Bloom Time: Late Summer-Fall Height: 48-60 inches Spacing: 18-24 inches Light: Full Sun to Part Shade Soil Moisture: Wet to Medium USDA Zone: 3a-8b Seeds Per Oz: 67,000 Produces a plant with 4-6” narrow, pointed leaves and 8-10” flat-topped clusters of ½” white daisy-like flowers.