CHOOSING AND PREPARING A PLANTING SITE

• Asters prefer climates with cool, moist summers—especially cool night temperatures. In warmer climates, plant asters in areas that avoid the hot mid-day sun.
• Select a site with full to partial sun.
• Soil should be moist but well-drained, and loamy.
• Mix compost into the soil prior to planting. (Learn more about soil amendments and preparing soil for planting.)

PLANTING ASTERS

• While asters can be grown from seed, germination can be uneven. You can start the seeds indoors during the winter by sowing seeds in pots or flats and keeping them in the refrigerator for 4 to 6 weeks to simulate winter dormancy. They need this period of colder weather to kickstart germination.
• Sow seeds one inch deep in soil, placing them in a sunny spot in your home. Plant young plants outside after the danger of frost has passed in the spring. (See local frost dates.)
• The best time to plant young asters is in mid- to late spring. Fully-grown, potted asters may be planted as soon as they become available in your area (typically in the fall).
• Space asters 1 to 3 feet apart, depending on the type and how large it’s expected to get.
• Give plants plenty of water at the time of planting.
• Add mulch after planting to keep soil cool and prevent weeds.