Smooth Aster has masses of beautiful lavender daisy flowers with yellow eyes at the ends of the stems from late summer to late fall, which are most effective when planted in groupings. The flowers are excellent for cutting. Its narrow leaves remain dark green in color throughout the season.
Smooth Aster is a dense herbaceous perennial with a mounded form. Its relatively fine texture sets it apart from other garden plants with less refined foliage.
Smooth Aster will grow to be about 3 feet tall at maturity, with a spread of 24 inches. It tends to be leggy, with a typical clearance of 1 foot from the ground, and should be underplanted with lower-growing perennials. The flower stalks can be weak and so it may require staking in exposed sites or excessively rich soils. It grows at a medium rate, and under ideal conditions can be expected to live for approximately 10 years. As an herbaceous perennial, this plant will usually die back to the crown each winter, and will regrow from the base each spring. Be careful not to disturb the crown in late winter when it may not be readily seen!
This plant does best in full sun to partial shade. It prefers to grow in average to moist conditions, and shouldn't be allowed to dry out. It is not particular as to soil type or pH. It is somewhat tolerant of urban pollution. This species is native to parts of North America. It can be propagated by division.
Smooth Aster is a fine choice for the garden, but it is also a good selection for planting in outdoor pots and containers. Because of its height, it is often used as a 'thriller' in the 'spiller-thriller-filler' container combination; plant it near the center of the pot, surrounded by smaller plants and those that spill over the edges. It is even sizeable enough that it can be grown alone in a suitable container. Note that when growing plants in outdoor containers and baskets, they may require more frequent waterings than they would in the yard or garden.