Symphyotrichum cordifolium (Fr: aster à feuilles cordées | En: heart-leaved aster, blue wood aster)

Heart-leaved Aster

Symphyotrichum cordifolium
Alternative names: Blue Wood Aster, Cordleaf Aster
French: Aster à feuilles cordées

Heart-leaved Aster is a must-have for fall gardens, especially in urban and partially shaded spaces. It bursts into bloom from September through November, often providing the final splash of colour before winter. Its lavender to soft white flowers are a welcome sight late in the season and serve as an important nectar source for pollinators.

This aster grows well in part shade to full sun and is adaptable to a range of soil conditions. Though typically under 1 metre tall, it can grow larger—up to shrub-like size—in moist, rich soil with added nutrients.

A valuable member of woodland edges, gardens, and roadsides, S. cordifolium is common throughout the Ottawa Valley and eastern North America. It spreads gently, making it a great companion plant near trees, shrubs, or along paths.

This species supports a wide range of biodiversity—it attracts bees, butterflies, and other insects, and provides food and shelter for birds and small mammals. It is also a larval host plant for the Pearl Crescent butterfly (Phyciodes tharos), adding even more ecological value.

Height & Spread: 30–90 cm tall, 30–60 cm wide (can exceed 1 m with water/fertilizer)
Bloom time: September to November
Light: Part shade to full sun
Moisture: Moist to dry once established
Soil: Adaptable; prefers rich, well-drained soil
Habitat: Woodland edges, roadsides, gardens
Ecological benefits: Nectar for pollinators, host plant for butterflies, food/shelter for wildlife
Edible: Not edible