Aster tradescantii

Aster tradescantii, also known as Symphyotrichum tradescantii, is a North American wild species that deserves to be discovered by gardeners. It reveals itself in autumn, when it forms a superb ball covered with countless small white flowers, followed by feathery, silvery seeds. Planted in rich and moist soil, this modest plant from the rocky shores of Maine and Vermont undergoes a metamorphosis and grows to significant dimensions. This very hardy perennial is the star of the garden in the late season.

Aster tradescantii belongs to the aster family. It is native to northeastern North America, specifically Newfoundland and Labrador, the states of Maine, Massachusetts, and Vermont. In nature, it is found on wet, rocky, and gravelly shores, in fissures filled with silt, between rocks in rapids, or along freshwater estuaries. This perennial grows from a non-invasive clump-forming crown with short rhizomes. Its above-ground vegetation is deciduous, emerging in spring and drying up in autumn. With rapid growth, the plant forms a rounded, tightly packed clump that is generally less than 70 cm (28in) tall, but can reach up to 1.50 m (5ft) in all directions in rich, deep, and moist soil. Flowering generally occurs from September to late October. The 'flower' is actually a small head with white petal-like peripheral flowers. The central flowers (the heart) are white and then turn brown. Together, they form bouquets of incredibly delicate stars. This aster develops strong, well-branched, smooth, dark-coloured stems. The leaves of this aster are thin, pointed at their tips, and dark green. The plant self-seeds spontaneously in the garden, abundantly if the conditions suit it.

The Tradescant Aster is interesting in a large rock garden that is not too dry or between the stones of a pavement, where it forms a small, tightly packed tuft. But it is most spectacular in a large flower bed. Associate it with autumn asters laevis and turbinellus, both of which are also intrepid and charming. It also forms a beautiful ensemble with Alcea x Parkallee, an imposing Malvaceae with pink flowers, a remontant rose with white or pink flowers, and Miscanthus Yaku Jima with feathery panicles... poetic and opulent, it blends very well with other plants in a flower bed, in partial shade or in the sun.