An early-fall bloomer, 'Avondale' starts to bloom just as the summer perennials are fading. Light to darker blue flowers surround a yellow center and are borne prolifically. The lower leaves are heart-shaped, while the upper leaves are ovate to tapering. Some shade is beneficial for this plant 2-3 feet high. Z. 3-8

Aster as a groundcover? Yup, that's how A. ericoides 'Snow Flurry' functions, and it's smothered with hundreds of half-inch white flowers in September. Easy to grow in full sun or part shade, it quickly forms a dense (non-invasive) mat when planted 8-12 inches apart. Be among the first to try this exciting new use for Asters! Z. 5-8

A beautiful introduction by Alabama wildflower enthusiast Jan Midgley. Route 51 in Shelby County, Alabama, is where she found this plant growing. Smoky blue flowers on 2.5-foot stalks grace this plant from August to October. Just plant it in full sun and well-drained soil, and step back! Z. 6-9

An outstanding autumn perennial, 'Bluebird' is an introduction of the Mt. Cuba Center in Delaware. The former director, Richard W. Lighty, selected this Aster for its floriferousness and tidy, upright habit that requires no staking if grown in full sun. The sumptuous violet-blue flowers with golden yellow centers are borne in fall on a 4-5-foot plant amid clean, disease-free foliage that is an appealing grayish green. Not fussy about soil or moisture, 'Bluebird' can be pinched back through June to control height and form. Z. (4)5-8

A more demure Aster than the taller varieties, 'October Skies' is bushy and comparatively shorter-growing, with intensely blue flowers in fall. May grow to about 18 inches with equal or slightly greater spread in full sun and well-drained soil. Z. 5-8

Bold leaves resemble Swiss chard. In late summer or early fall clusters of blue flowers with yellow centers herald the arrival of a new season on tall stalks 3-5 feet high. Unlike other tall Asters, this one requires no staking. An introduction from the Jin-Dai Botanical Garden in Tokyo. Z.4-8