Sow in average soil in full sun after danger of heavy frost. In frost-free areas, Sow in fall to early spring. Sow seeds about 12" apart and cover with 1/4" of fine soil. Firm lightly and keep evenly moist.
How to Grow
Seedlings emerge in 14-21 days. Feed plants in the spring by topdressing with compost or well-rotted manure. You can also pinch out stem tips in the spring and again in early summer to encourage branching, more flowers, and less staking due to the shorter, sturdier growth pinched plants produce. Dont pinch after June 15 (July 1 from Zone 7 south) or you will remove the emerging flower buds. Tall asters should be staked early, in spring or very early summer. Mulch asters to keep moisture in the soil, and deadhead regularly or cut the stems back immediately after flowering to prevent cultivars from self-Sowing. Most asters will need dividing every two or three years.
Asters are great in perennial borders, meadows, and wild gardens designed for late-season color. They combine well with solidago, sedum, monks-hoods and ornamental grasses. For lovely cut flowers, cut aster stems when about three-quarters of the flowers have opened. Split the stems under water if they are woody to encourage water uptake.