Black-eyed Susans (Rudbeckia)

June 1, 2016 Summer Perennials

Black-eyed Susans are so floriferous and distinctive that they are easily recognized by gardeners in the Northern Hemisphere. Their broad branched clumps of golden daisies with brown cones are long-blooming, offering a late summer, constant color intensity that cannot be equaled by any other flower. Rudbeckias are native, easy-care perennials and not fussy, thriving in whatever soil they happen to be planted in. They also make beautiful cut flowers.

There is no mistaking Rudbeckia fulgida (also known as “orange coneflower” or “perennial coneflower”) for another perennial, with one exception. Its close relative, Gloriosa Daisies, Rudbeckia hirta (which are also called by the common name Black-eyed Susans) are not perennials but annuals, or short-lived perennials. This resemblance, plus having the same name, is confusing to a gardener who assumes they have planted the perennial. Rudbeckia fulgida is the perennial and Rudbeckia hirta is the annual.

Other differences in the two plants are that hirta self-seeds easily and fulgida is propagated vegetatively by cuttings or division and does not spread. The Gloriosa Dasies will germinate everywhere and bloom in many brilliant shades of golds, autumn bronzes and mahogany, while Fulgida stays put for a long life.

Both plants thrive and bloom longer with the dry, intense sunshine and cooler climates of the western Rocky Mountains. They both grow stockier and shorter in the west. This increases the uses of Black-eyed Susan, fulgida for the foliage is attractive enough for landscaping borders, foundation plantings, parking lot planters, and of course, rock gardens.

Above, you will notice that the attractive foliage and flowers of Rudbeckia are enhanced by the burgundy colored shrubs they are planted next to. They are also good companions for the blue-lace of Perovskia or Russian Sage, tall Sedums, and any of the perennial grasses because of the differences in both textures, heights and colors.