Like a lot of people, I have an allergy to ragweed. My affliction isn't as bad as the debilitating reaction I used to have to spring tree pollen before I built up some immunity to it, but it's enough that I can call myself a ragweed sufferer. The eyes invite rubbing, the throat feels like a disused mine shaft, and the sinuses open and close as they please.
Ragweed starts spewing out its pollen dust in August, peaks in September and persists until the first frosts.
Everyone has heard of ragweed, but few, I wager, would recognize it if it were sitting outside the door. It's an annual that expands with almost shrublike vigor in one season, each plant growing as high as six feet, with feathery leaves that resemble those of the wormwood.
The male flowers cluster at the top of the plant. The female flowers sit in the joints of the leaves and branches below. The male flowers generate millions of microscopic grains of pollen that ride the air. Some alight on the female blooms a few inches away, but most fly many miles so that they can land in your throat.
For a reason that bears only passing logic, another plant entirely has taken the rap for the ragweed, to wit, the goldenrod. People look at the common goldenrod (Solidago canadensis) and say, "Hey, look at all that pesky ragweed." This may be because the goldenrod is conspicuous, with its lanky stems and the way it spreads by runners to colonize roadside ditches and open fields. Most of all, its wands of yellow blooms wave like banners during ragweed season. The common goldenrod species is not suited to the cultivated garden, but it is not public enemy No. 1.
Think of it as the innocent fugitive at the center of an Alfred Hitchcock film. Can a menacing crop duster be far behind?
Like ragweed, most plants that trigger allergic reactions generate airborne pollen. Reproducing this way is a hit-or-miss affair, so the plants overdo the pollen. Spring is green with the pollen grains of oaks, elms and maples, along with grasses.
Goldenrods, by contrast, are among the flowers that entice insects to move the pollen from one plant to another. Pollinator pollen tends to be big and sticky, not the windblown stuff of stuffy noses. Nevertheless, the advertisements for allergy medications are full of blooms that don't cause allergies — a daisy reads better than a gramineous inflorescence.
Anyway, the goldenrod's September and October blooming period offers its own value to the gardener, as one of those steadfast perennials that will add floral highlights to the late-season garden.
Between now and the leaf drop of early November, the garden is entering what I think is the most beautiful phase of the year. As I've said before, it is a period in which flowers are just one element and one that relies on the mature leafy forms of perennials, grasses and annuals, along with the ornament of shrubs and trees before, during and after leaf coloration.
But plants that do flower late are valuable because they add the fizz to the cocktail. The common goldenrod may be a bit rank and invasive for the garden, but others have been developed that are smaller, neater, non-spreading and, in sum, deserving of far more use.
There are more than 60 species of goldenrods native to the Mid-Atlantic region alone, and I can't help thinking that breeders have merely scratched the surface in developing garden-worthy varieties. The number of pollinators drawn to goldenrod is amazing. The individual flowers of each spray are tiny daisies. It is worth pulling up a stool and observing close up both the blooms and the creatures drawn to them. They are favored in particular by tiny native bees.
The best known garden goldenrod may be Fireworks, a variety of the wrinkle-leaf goldenrod that grows to just four feet and is smothered in fine-textured sprays of golden-yellow blossoms for most of September and October. Another tried-and-true goldenrod is Golden Fleece, a variety of the dwarf goldenrod. It grows to about 24 inches, but its leaves and flower spikes are bolder than those of Fireworks.
A hybrid from Germany named Crown of Rays (Strahlenkrone) is another compact, floriferous variety that blooms in early summer, but it will re-bloom generously in the fall if cut back after the initial show. Goldenrods are sun lovers and are not for wet soils, though the wreath or bluestem goldenrod will be happy in a little shade.
My new favorite goldenrod is the plumed goldenrod, Solidago plumosa. It is about 24 inches high, grasslike, extremely fine-textured and about to smother itself in yellow blooms against red stems. You can see a drift of it at the Regional Garden of native plants at the U.S. Botanic Garden.
Unfortunately, it's not readily available in the nursery trade, probably because it is rare and endangered in its native North Carolina. I'd like to think it could be propagated without harming the wild population, much as the Tennessee coneflower has been grown and sold. The plumed goldenrod would be a great front of the border plant, perhaps as a filler, much like a grass or sedge with the bonus of erupting into bloom in the weeks ahead.
Asters, cousins to the goldenrods, provide another companion plant, including such superior varieties as Raydon's Favorite and Bluebird. The lower-growing, small-flowered calico aster deserves more use. Lady in Black is noted for its deep purple foliage and tiny pink blooms in arching sprays.
All these lovely late-season perennials, and especially the goldenrods, have a place in most gardens. Unlike the wretched ragweed, they are not to be sneezed at.