While New England Aster seeds can germinate without cold stratification, giving them a cold, moist stratification period for 2 to 4 weeks significantly improves germination rates. Direct sowing seeds outdoors in late fall or winter naturally provides this cold period. If starting seeds indoors in the spring, place seeds on a damp paper towel in a sealed bag in the refrigerator for a few weeks before planting.

New England Aster is a long-lived perennial. Plants usually focus on developing deep roots and foliage during their first growing season and typically produce their abundant purple blooms starting in their second year.

To keep plants compact and bushy, "pinch back" the growing tips by a few inches in early summer (around late May to mid-June). Stop pinching by early July so you don't remove the developing late-season flower buds.

New England Aster is a native North American wildflower rather than an invasive species. However, it can self-seed readily in ideal conditions. If you want to prevent volunteer plants from spreading, simply deadhead spent blooms in late autumn before seeds drop.