Symphyotrichum oblongifolium  ‘October Skies’ (Aromatic Aster)

october skies aromatic aster symphyotrichum oblongifolium purple flower clump form

While there are many lovely Asters, ‘October Skies’ is my personal favorite. Asters are stars of the autumn garden, blooming prolifically at a time when most perennials are beginning to go to rest for the season.

I love October Skies because of its compact, arching habit with flowers all along the stems, creating a solid mass of blossoms that covers the entire plant. This is distinctly different from most other Asters, which bloom only on the top of their stiffly vertical stems and are prone to losing their lower leaves which produces a “brown ankle” effect that needs to be disguised by lower plants in the foreground. By contrast, ‘October Skies’ lends itself well to use in the front of the border. This plant is also highly resistant to powdery mildew, which can be an issue with other asters.

Once established, ‘October Skies’ is very drought tolerant and well adapted to our alkaline soils. Its late bloom time makes it a valuable late season source of pollen and nectar for beneficial pollinators, and it is frequently visited by butterflies. The seeds are a favorite food of Goldfinches. While Asters are a favored food of rabbits ‘October Skies’ is less vulnerable than most, especially once it gets past the spring months.

As with all herbaceous perennials, this one should be cut to the ground sometime before new growth begins in the spring. I prefer to leave it standing through the winter months to provide shelter and food for native insects and birds and cut it back in March or April.

It pairs beautifully with ornamental grasses and other fall blooming perennials such as Sedum, Solidago, Vernonia and Calamintha.

The common name “Aromatic Aster” derives from the fragrance emitted when the foliage is crushed. While we at Johnson’s Gardens still stubbornly refer to this plant as “Aster”, it – along with most other North American Asters – was reclassified in 2015 and assigned the Genus name Symphyotrichum. This name dates to 1832 and replaces the name Aster through the Principle of Priority in which the earliest recognized name overrules later name designations.

October Skies In a Nutshell

Mature height: 18”-24”
Mature spread: 24”-30”
Light requirement: Full sun to light shade
Growth form: Arching stems. Clumping habit.
USDA Hardiness Zone: Zone 4
Flower: Soft lavender-blue daisy with yellow center
Bloom Season: Late Summer into Autumn
Especially valuable for: Attracting Butterflies & other beneficial pollinators. Late season bloom

october skies aromatic aster symphyotrichum oblongifolium purple flower clump form
october skies aromatic aster symphyotrichum oblongifolium purple flower clump form
october skies aromatic aster symphyotrichum oblongifolium foliage and flowers