Symphyotrichum cordifolium

Symphyotrichum cordifolium: A Pale Blue Haze for Fall Shade

Heart-leaved aster wears its heart on every leaf, literally. Big sprays of tiny pale blue daisies light up the shade in fall, right when you'd given up on that dark corner. A NATIVE ROMANTIC WITH ZERO CHILL.

Plant Characteristics:

• Botanical Name: Symphyotrichum cordifolium (formerly Aster cordifolius)
• Common Name: Heart-leaved Aster, Blue Wood Aster
• Height: 60–90 cm (2–3 ft)
• Spread: 45–60 cm (1.5–2 ft)
• Flowers: Small pale blue to lavender daisies, each with a yellow centre that turns reddish, in large branching sprays
• Bloom Time: Late summer to fall (September to October)
• Foliage: Heart-shaped, toothed green leaves, largest near the base
• Features: Tolerates dry shade once established

Where to Plant: Plant it along a woodland edge, under high trees, or in the dappled part of a mixed border where it can float above lower plants. It looks best in drifts, where the sprays of flowers merge into a haze, and it tolerates dry shade once established.

Companion Plants: Plant heart-leaved aster in a shady or part-sun native woodland bed with spring phlox and wintergreen. Phlox divaricata opens pale blue woodland phlox at 30 to 38 cm in April and May. Gaultheria procumbens carpets the ground at 10 to 15 cm with glossy leaves and red winter berries. Eurybia divaricata adds small white wood asters at 30 to 75 cm from August to October. Carex pensylvanica fills in at 15 to 30 cm with fine, arching blades.

Plant Care: Plant in part sun to shade in average, well-drained soil. It handles clay and rocky soil and tolerates dry spells once established, though it flowers more heavily with steady moisture. Water through its first season. It self-seeds in open soil. Cut the flower stems after bloom if you don't want seedlings, or leave them for the birds and pull extras in spring. Cut back to the ground in late fall or early spring. Divide in spring every few years if the clump gets crowded.

History: Heart-leaved aster is native to eastern North America, including Ontario, Quebec and the Maritime provinces, where it grows in open woods, clearings and woodland edges. Its name cordifolium means heart-shaped leaf, and it was long called Aster cordifolius.

Final Thoughts: It handles dry shade once settled, and the bees and butterflies throw a farewell party on it. LOVE IN THE SHADE. GO ON.