Summer ends this weekend, but late-blooming flowers are far from finished. One can’t help but notice the conspicuous school-bus-yellow daisies, known as Black-eyed Susans, which thrive along our Colorado roadsides. (Most are Rudbeckia hirta, but other species also grow here.) Happily for us gardeners, there are cultivated forms of Rudbeckia that continue to brighten our home landscapes well into autumn.
With such a gorgeous flower to begin with, plant breeders have had a field day coming up with dazzling can’t-resist cultivars. There are a variety of familiar yellow daisies, some with double petals, in various sizes. ‘Goldstrum’ is one popular variety (at bottom). Blossoms may also come in orange, russet and mahogany, usually with a prominent central black cone; these fall-hued flowers are known as Gloriosa Daisies (left). Some cultivars, including ‘Irish Eyes’ and ‘Prairie Sun’ (below), have yellow petals surrounding a spring-green cone that ages to brown.
In all cases, upright, hairy stems support rough, lance-shaped leaves. They don’t look very impressive until they start to bloom—but the reward is more than worth the space they take up earlier in the season! The flowers last a long time, too. Although wild plants may reach four feet in height, most cultivars are more compact, appropriate for our smaller gardens.
Because Rudbeckias are native to Colorado, they are easy to grow here. These tough plants perform best in full sun and average garden soil. They belong in the “moderate water” zone of a xeric landscape. Too much fertilizer and water may result in weak stems needing staking. Plants may be started from seed or purchased as transplants, and will self-sow if not deadheaded.
With such bright flowers, Rudbeckias need equally bold companions. Their warm colors are striking set against the periwinkle purple of Russian Sage or a blue-toned juniper, and are complemented by the fall copper color of Bluestem grasses. Try them toward the back of a perennial border, or mass plants for maximum impact.
Cutting the flowers for indoor use promotes additional bloom. When the flowers fade, the now petal-less central cone is a striking addition to dried arrangements. If Rudbeckias have any fault, it lies with their brief lifespan. Most are biennials or short-lived perennials—their only drawback, because you’ll want them to last forever!