Symphyotrichum shortii

Symphyotrichum shortii: Sky-Blue Asters for the Woodland Edge

Short's aster has a name that sets expectations low, then overdelivers. Pale blue daisies with yellow centres that turn reddish purple once the bees have visited, like it's blushing about it. THE BEES HAVE BEEN HERE, AND EVERYBODY KNOWS IT.

Plant Characteristics:

• Botanical Name: Symphyotrichum shortii (formerly Aster shortii)
• Common Name: Short's Aster
• Height: 60–90 cm (2–3 ft)
• Spread: 30–60 cm (1–2 ft)
• Flowers: Pale blue to violet-blue rays around yellow centres that turn reddish purple after pollination
• Bloom Time: Late summer to mid-fall (August to October)
• Foliage: Narrow, heart-shaped leaves on slender stems
• Features: Host plant for pearl crescent and silvery checkerspot caterpillars, seeds eaten by birds

Where to Plant: Plant it along a woodland edge, under high tree canopy, or in a garden that gets morning sun or dappled light. The stems lean forward when full of flowers, so put shorter plants in front. It handles dry, rocky or limestone-based soil, which makes it useful in thin, tricky spots under trees.

Companion Plants: Filipendula 'Venusta' towers behind at 180 to 240 cm with pink plumes from June to August, before this aster takes over. Coreopsis verticillata 'Zagreb' adds fine-textured yellow flowers at 30 to 46 cm from June to August. Platycodon 'Astra Pink' brings pink balloon flowers at 20 to 25 cm in the same months along the edge. The group suits full sun or partial sun and carries colour from June into October.

Plant Care: Plant it in average to dry, well-drained soil. It doesn't need rich soil or fertilizer. Water through the first season, then only during long droughts. Leave the seed heads standing for the birds and cut the stems down in early spring. It can spread by seed; pull or share any extra seedlings. Divide in spring every few years if the clump gets crowded.

History: Short's aster grows wild in southern Ontario and much of the east-central United States, in open woods, thickets and on rocky slopes. It honours Charles Wilkins Short, a 19th-century Kentucky physician and botanist, so the name says nothing about its height.

Final Thoughts: Late nectar for bees and butterflies, caterpillar food and seeds for birds. That's a full-time job. PUT IT ON THE PAYROLL.