Riddell's Goldenrod is a rare plant to find in Missouri, but it is pretty easy to grow and needs to be used more often in native plantings. It is one of the few "flat-topped" goldenrods: the inflorescence has a more horizontal presentation than the other goldenrods. Other flat-topped goldenrods include Rigid Goldenrod, which likes drier soils, and White Upland Aster, which has white flowers & also prefers well-drained environments.
While it is normally found growing in high-quality wet-soil habitats, it can certainly survive some neglect in the home landscape. We've had about a dozen plants growing in 3-gallon pots for several years now. They suffer from lack of water during our dry summer months and are left unprotected outdoors all winter. It would be better if one didn't subject these gorgeous plants to this type of torture, but it goes to show that they are fairly hardy.
Goldenrods, with their showy, prominent, yellow flowers, are typically blooming at the same time as the various ragweeds. The conniving ragweeds are not showoffs, so their inconspicuous, pollen-laden, allergy-inducing flowers don't get blamed for the fall allergies that they cause. Instead, the blame is laid upon the (mostly) innocent goldenrods. Don't be tricked. Plant goldenrods--for the bees, butterflies, and birds, and to make your neighbors jealous.
Uses: Bees, butterflies, rain gardens, fall color, anarchy
Bloom time: August - September
Height: 36 to 48 inches
Space: 12 to 18 inches
Sun: Full sun to light shade
Moisture: Average to moist
Seed: Harvest in November. We treat ours to 8 to 10 weeks cold moist stratification, but this may be unnecessary.