How to Grow China Aster

1). Choose an area of the garden that receives full sun. Amend the soil with 3 to 4 inches of compost to aid in drainage.
2). Rake the flower bed until smooth and sprinkle China aster seeds 10 to 16 inches apart on the soil surface. Cover with an eighth-inch layer of coarse sand. The seeds require light to germinate, so don't cover them too deeply.
3). Water the bed with the mist setting on the sprinkler head or garden hose so you don't wash away the seeds. Keep the soil moist while seeds germinate, which takes 10 to 20 days.
4). Apply a 2-inch layer of mulch on the soil around the China asters to help insulate the soil and keep the roots cool. Keep the mulch as least 2 inches from the base of the plants.
5). Water the China asters just enough to keep the soil slightly moist at all times. Don't over-water.
6). Deadhead the newer, re-blooming varieties of China aster by pinching flowers from the plant when they fade. Most China aster plants last for only three to four weeks and don't require deadheading.