Cone Estate Goldenrods
Their long bloom season – till frost – along with their variety, ease of growing and drought tolerance make the Solidagos great garden plants.
Drive along the Blue Ridge Parkway when goldenrod is in bloom – from late July until the first frost, depending on species – and you could see nearly a sixth of the goldenrod species in the world, and nearly half of those native to the Southeast. Seeing 20 of the approximately 130 species in the Solidago genus is one thing, but identifying them is quite another.
“Without doubt, the Goldenrods are the most difficult genus in which to identify species – not even excepting the Asters, which are more numerous,” writes Richard Smith in “Wildflowers of the Southern Mountains.” Not only do goldenrods hybridize in the wild, he explains, but the flowers of all but one are small and yellow. (The exception is the white-flowered Silverrod, S. bicolor.) Botanizers must “give attention to the vegetative parts, especially the basal leaves,” if they wish to tell one goldenrod from another.
That being said, the goldenrods can be grouped according to the shapes of their flower clusters. In “Wildflowers of the Blue Ridge Parkway,” John Alderman distinguishes those whose flower clusters spread like plumes, from those that resemble slender wands, or that form dense, club-like clusters on upright stems. Still others “have gracefully arching clusters similar to the branches of an elm tree,” he writes. Goldenrods also have varying bloom seasons, and vary tremendously in height. For example, Blue Ridge Goldenrod (S. spithamaea), a rare endemic of southern mountain balds, is less than 18 inches tall, while Giant or Late Goldenrod (S. gigantea) can tower to seven feet.
Although goldenrods are common roadside plants, they work well in gardens too. They add a splash of late season yellow in open beds or borders, make excellent cut flowers, and are beloved of butterflies. One of my butterfly gardening books includes goldenrods on its “Master Plant List” of 30 flowering plants for butterflies. (Other wildflowers on the list include coneflowers, sunflowers, yarrows, asters and milkweeds.) The fall I spent netting and tagging migrating monarchs at Cape May Point, N.J., turned me into a fan of Seaside Goldenrod (S. sempervirens). When the monarchs were moving down the coast, the seaside goldenrod in the dunes was loaded with them. Garden writer C. Colston Burrell recommends goldenrods for “the wild garden, streamside, or naturalized in meadow gardens,” in addition to beds and borders.
Need additional reasons for adding goldenrods to your garden? Deer and rabbits won’t bother them, but songbirds, particularly goldfinches, and small mammals consume their seeds in winter. Goldenrods can be gathered after they have gone to seed for use in dried arrangements. And they’re easy to grow. They’ll thrive in average garden soils – and make do in poor soil. Once established, they are drought-tolerant. Most favor full sun, but some species – one grows in the woods along my north-facing driveway – bloom well in shady locations. Solidago, the genus name, comes from the Latin solido, “to make whole or cure,” a reference to the plants’ healing power to treat urinary, stomach and digestive system ailments.
Although most goldenrods are North American natives, they became popular as garden plants in Europe before they did here. Shorter hybrid varieties developed for the European cut-flower industry in the mid-20th century have increased their popularity as garden plants. A five-year evaluation of goldenrods for garden use conducted by the Chicago Botanic Garden in the 1990s concluded that garden hybrids “are more important in cultivation than any of the species” – with good reason. They grow either from thick crowns or from rhizomes; rhizomatous species can spread aggressively. I’ve spent years trying to rid my raspberry patch of wild goldenrod, at the same time I’m transplanting divisions from a clumping variety in my flower beds. The botanic garden’s evaluation report notes that “a rhizomatous species may require division every three years to keep the plants in check,” while clump-forming varieties “grow at a moderate pace and should not require division for many years.”
Goldenrods for the Garden
The goldenrods that scored highest in the Chicago Botanic Garden’s evaluation included two low-growing garden hybrids, ‘Baby Sun’ and ‘Goldkind’; cultivated varieties of Rough Stemmed (S. rugosa ‘Fireworks’), False (S. sphacelata ‘Golden Fleece’) and Broad-leaved Goldenrod (S. flexicaulis ‘Variegata’); and Stiff Goldenrod (S. rigida). But there are other great possibilities. Just make sure you match the goldenrod you buy with its native habitat. ‘Variegata,’ for instance, is good for semi-shaded areas, where its bright, gold-mottled leaves light up their surroundings. In beds and borders, site goldenrods according to their height and spread. ‘Golden Fleece,’ the most compact of the goldenrods the Chicago Botanic Garden evaluated, spreads slowly to over three feet. ‘Fireworks,’ which received the highest rating of all, thanks to its fine-textured foliage and arching, flowery stems, is a slow spreader, but needs space. At maturity, it’s shrublike, 54 inches tall and 76 inches wide.
Some goldenrods are susceptible to powdery mildew; the high-scoring evaluated varieties showed no or minor infections. Scoring took into account floral and habitat display, winter hardiness, cultural adaptability and disease and plant resistance. Many other goldenrods are good for gardens, including Wreath (S. caesia), Zigzag (S. flexicaulis) and Silverrod for moist shade; Seaside and Lance-leaved (S. graminifolia) for butterfly gardens; and Showy (S. speciosa) and Early Goldenrod (S. juncea) for sunny borders.
Companion Plants for Goldenrods in the Garden
Take a tip from Mother Nature, when it comes to combining goldenrods with other plants in your garden. Their bright yellows are gorgeous with fall asters, sunflowers, Joe-Pye weed, coneflowers, ironweed, phlox, salvias and grasses.
Goldenrod is frequently blamed for causing hay fever, but it’s not the culprit. Its pollen is heavy. The bees and butterflies that mob it move its pollen, not the wind. To find what’s causing you the sneezes, look to the ragweeds, whose blooms are inconspicuous, but which open at the same time the goldenrods bloom. They and other plants whose pollen is airborne are at fault, not the goldenrods.