Solidago altissima aka Tall Goldenrod

Solidago altissima, or tall goldenrod, is a wildflower that lives for years. It belongs to the daisy family, Asteraceae. It grows wild across much of North America, including Canada and Mexico. Chicago Botanic Garden notes that it is absent from the far West. It is South Carolina’s state wildflower. Some goldenrods look alike, so telling them apart can be hard. People often mistake this species for Canada goldenrod.

Plants grow upright to 4–6 feet [1.2–1.8 metres], by Chicago’s account. NC State gives a wider range of 2–6 feet [0.6–1.8 metres]. Stems grow alone or in groups and bear white hairs. Narrow green leaves grow in turn along each stem. They taper to a point and get smaller toward the top. Small teeth line their edges. Hairs often cover their lower sides. Fibrous roots and creeping rhizomes, or spreading underground stems, form dense clumps.

Small yellow flower heads crowd into broad, cone-shaped panicles, or branched flower clusters. These give the blooms a soft, feathery look. One plant can carry about 1,500 flower heads. Chicago lists blooms from July through October. NC State lists August through November. Each plant blooms for about three weeks, by NC State’s account. The blooms have a scent. They suit both fresh and dried flower displays. Bees, butterflies, and beetles visit the flowers for their rich nectar. The heavy pollen does not cause hay fever. Ragweed blooms in the same season.

Grow tall goldenrod in full sun for a well-lit site. It can also grow in part shade. It does well with average moisture and soil that drains well. It grows in several soils, from loam to heavier, clay-rich ground. Plants cope with dry spells but may lose their lower leaves. Chicago lists USDA zones 3–8; NC State lists zones 5–10. Growth is moderate, and the plant needs little routine care. Grow new plants from seed or split clumps you have.

Tall goldenrod suits borders, wildlife gardens, and large planting areas. It draws birds and butterflies. Wavy-lined emerald larvae feed on it. Dead, hollow stems give native bees a place to nest. Leave cut stems 1–2 feet [0.3–0.6 metres] tall for these bees. Rhizomes grow strongly, so this plant is a poor choice for small beds. It also gives off compounds that can curb nearby plant growth. Powdery mildew sometimes affects the leaves in fall. Deer tend to leave it alone.