Aster novi-belgii Sarah Ballard

Aster novi-belgii 'Sarah Ballard' is a tall perennial, which offers beautiful and numerous blue-mauve star-shaped flowers with particularly slender petals from late summer to autumn. Robust, romantic, and charming in its simplicity, it is a reliable choice to adorn your sunny or lightly shaded, moist flower beds at the end of the season.

Aster 'Sarah Ballard' belongs to the large botanical family of Asteraceae, which includes many well-known ornamentals such as daisies, rudbeckias, echinaceas... New Belgium, which gives it its name, is a region located on the northeast coast of the United States, also known as New Netherland or New Holland. This aster grows in American prairies, and has spread widely worldwide following its introduction in horticulture in the form of countless varieties of varying heights. It should be noted that botanists now classify this species in the new genus Symphyotrichum, which includes New World asters.
Aster novi-belgii produces tall, upright stems, bearing numerous star-shaped flowers between August and October (or even November). Each "flower" is actually a cluster of many flowers: the central, golden ones are "tubular" and fertile. The peripheral, "ligulate," ones are sterile and attract pollinating insects. The deciduous foliage, measuring between 5 and 10 cm (2 and 4in), is lanceolate, tender green, and smooth (which distinguishes it from the New England aster, another North American species with rough leaves).

The 'Sarah Ballard' variety is distinguished by an upright habit reaching 80 cm (32in) to 1 metre (3 feet) in height, with a minimum diameter of 50 cm (20in) due to its rhizomes. In this variety, the "petals" are a beautiful bluish mauve, and their tips are sharper than in most other New Belgium asters. The centres of the heads are golden, then turn reddish-brown. The feathery seeds are also attractive and retain a sculptural aspect for a good part of the winter.

The 'Sarah Ballard' aster is a reliable and hardy plant that appreciates moist, fairly fertile soil. Prolonged periods of drought often lead to the appearance of powdery mildew, a fungal disease that manifests as grey or white spots on the leaves. This disease is not harmful to the plant's health but is not very attractive. A sunny location is preferred, or light shade. When exposed to too dense shade, the plant becomes limp, and blooms less. Also avoid planting this aster in a very windy area that would make the stems bend. Each plant spreads through its rhizomes, eventually forming a beautiful clump. After a few years, it is advisable (and easy) to divide the clump to prevent the centre from hollowing out. If the plant likes its location, it may self-seed here and there.

The 'Sarah Ballard' aster is perfect for gardeners looking to enliven autumn flower beds, and it will find a place alongside other late-interest plants such as Japanese anemone 'Splendens' in partial shade, Ceratostigma plumbaginoides in full sun, and grasses like Andropogon 'Prairie Sommer' and panic 'Blue Darkness'.