Virtues: Denver Daisy is a long-blooming, heavy-blooming variety of North American native black-eyed Susan (Rudbeckia hirta). It provides constant cheerful color in the summer garden while feeding bees and other pollinators. It tolerates poor soil, high heat and moderate dry spells and performs equally well in the ground and in a container. Cut its flowers for bouquets, where they will last a long time; meanwhile the plant will continue to crank out more blooms in the garden.
Common name: Denver Daisy black-eyed Susan
Botanical name:Rudbeckia hirta ‘Denver Daisy’
Exposure: Full sun
Season: Late spring to autumn, for flowers
Flowers: Bold yellow petals with bronze-brown markings at their base surround a deep chocolate eye. This is an example of a composite flower, wherein the yellow “petals” are actually single ray flowers and the brown “eye” is a cluster of tiny disc flowers. As a whole these individual flowers form a composite “daisy” up to 6 inches around.
Foliage: Slightly hairy, deep green, elongated oval leaves line hairy stems.
Habit: Denver Daisy grows between 18 and 28 inches tall and up to 24 inches wide. The flowers rise just above the foliage, creating a dense mound of yellow color.
Origins: This cultivar of Rudbeckia hirta was bred by Benary and introduced in 2009 by PlantSelect in commemoration of the 150th anniversary of the founding of Denver, Colo. The species R. hirta is native to roughly the western half of North America and it has naturalized across most of the continent, growing in prairies, meadows, open woods and woodland edges.
How to grow Denver Daisy: Site in full sun and average soil with good drainage. Once established this perennial can withstand short dry spells. This plant is a short-lived perennial that tends to perform best in its first year in the garden, so it is often treated as an annual to plant in early spring for a strong summer show. If you choose to try it as a perennial, leave the spent stems and foliage over the winter and then remove them in early spring to make way for new growth. This plant can also be divided in spring. USDA Zones 6–9.
Image credit: chapin31 / iStock / Getty Images