Solidago ptarmicoides

Solidago ptarmicoides: A Goldenrod That Went Rogue in White

A white goldenrod? That's like a quiet rock concert. Yet here it is, flat-topped clusters of little white daisies on stiff stems, breaking every family rule. THE BLACK SHEEP OF THE GOLDENRODS.

Plant Characteristics:

• Botanical Name: Solidago ptarmicoides (also listed as Oligoneuron album and Aster ptarmicoides)
• Common Name: Upland White Goldenrod, Upland White Aster
• Height: 30–60 cm (1–2 ft)
• Spread: 30–45 cm (12–18 in)
• Flowers: White daisy-like heads about 1 cm (½ in) across with creamy to pale yellow centres, in flat-topped clusters
• Bloom Time: Midsummer to early fall (July to September)
• Foliage: Long, narrow, mostly smooth-edged leaves in a low basal tuft, smaller up the stiff stems

Where to Plant: It's made for dry, sunny spots: rock gardens, gravel beds, sandy slopes, prairie plantings and the front of a dry border. Plant several together so the white clusters read from a distance.

Companion Plants: Echinacea pallida rises to 60 to 120 cm with pink, drooping petals in June and July, a fellow prairie native. Geranium 'Cambridge' forms a 15 to 25 cm carpet with magenta flowers from May to July. Symphyotrichum shortii carries blue asters at 60 to 90 cm from August to October, right as the white goldenrod finishes. These all grow in full sun or partial sun.

Plant Care: Plant in full sun in sandy, gravelly or rocky soil with sharp drainage. Lean soil is better than rich soil here. Water while it establishes, then leave it alone except in a severe drought. It won't tolerate heavy, wet clay. No fertilizer or staking. Cut stems back in late fall, or leave them for winter interest and trim in spring. It doesn't spread aggressively and can stay in place for years.

History: Upland white goldenrod is native to central and eastern North America, including Ontario and Quebec, where it grows on dry prairies, sandy openings, rocky bluffs and limestone outcrops. It was long classified as an aster, and older references still call it Aster ptarmicoides.

Final Thoughts: Dry, sunny and lean is just how it likes it. Native bees and butterflies are already fans. PLANT THE REBEL.