Among the last native flowers to bloom, Asters are impressive with over 50 species found in the northeast alone, many being garden worthy. Against the gold of autumn, their deep purple and lavender blooms nodding in the breeze always catch my eye. I am fortunate to have many different species on my property and my walks at this time of year are delightful as I view the domestic and wild plants that grow here. Always filled with bees and butterflies, particularly Monarchs and Fritillaries, I’m not the only one who benefits from this last hurrah of Nature. Seed spread by the wind ensures that delight will increase in the years to come.
From the Greek meaning ‘star’, Asters are composite flowers with fertile disc florets in the middle with sterile ray florets on the outer perimeter forming the petals, occurring singly or in corymbs (clusters). Species range in height from six inches to eight feet tall, spreading up to three feet wide. While most flower better in full sun, they tolerate part shade and will thrive in moist to well-drained soil, as well as a wide range of pH. They are prone to mildew, rust, leaf spot and aster wilt, so good air circulation and frequent division of clumps are advised. The genus has recently been reclassified as Symphyotrichum but Aster is still recognized.
The most familiar species is New England Aster (S. nova-angliae). In the wild, purple is the most common color, however, many cultivars have been developed over the years with currently about 50 in cultivation. Available in red, pink, lavender, purple and white, their flowers are 1-2” wide, and they range up to 6’ tall and 3’ wide.
New York Aster (S. novi-belgii) is similar but is found in moister soils and swampy areas. Easily hybridized with over 300 cultivars available, the range of colors is vast. Height is 3-4’ with smooth green foliage, as opposed to the rough, hairy stems and foliage of the New England Aster.
Calico Aster (S. lateriflorum) has 1/4-1/3” white ray florets with disc florets that start yellow then turn purple-brown as they age, giving the impression of calico fabric when viewed from the distance, hence the name. Height ranges 3-5’.
Heartleaf Aster or Common Blue Wood Aster (S. cordifolium) has cloud-like clusters of ½” lavender flowers on erect wiry stems up to 4’ tall. It is a lovely sight to behold, one I look forward to every year.
For partial shade, White Wood Aster (S. divaricatus) and Large-leaved Wood Aster (Eurybia macrophylla) offer clusters of ½-1” white flowers in late summer over heart-shaped leaves. Both form a ground cover that even when not in bloom is charming.
Asters can be propagated by division, root and stem cuttings or by seed. Native plant nurseries offer species other than the common New England and New York Aster varieties regularly available. Hardy and tough, native asters are a great choice for your autumn garden.