Gorgeous Goldenrod

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This species of goldenrod grows as a robust tall perennial. Its long creeping rhizome (root-stem) with fibrous roots explores the soil just below the surface.

From this rhizome arise stiff tall stems that may grow only to 30 centimetres on poor sites, but up to more than two metres on rich sites or in a well-watered garden. There is no mass of leaves at its base, a condition common to many members of the aster family. Instead, long lance-shaped leaves extend outward from its stem, becoming smaller toward the tip. Typically, leaves range from five to 15 centimetres long by 0.5 to 2.2 centimetres wide, and bear several small teeth scattered along their edges. These leaves can feel smooth to slightly rough in texture. A rod- to pyramid-shaped, branched flower head crowns each stalk. Each flower head, which may easily exceed 10 centimetres in length and breadth, consists of hundreds of complex, small, bright-yellow flowers. Each of these composite blooms is constructed of an outside ring of tiny ray florets with petals united into a strap-shaped ray, and a dense mass of disk florets in which the petals are reduced into a tiny tube surrounding the style and stamens. At the base of each floret hides the hairy ovary from whose top arise many long, wispy bristles. These help waft the ripe seeds into the air and spread the species. The mass of florets is tightly cupped by numerous highly modified leaves called bracts. Flowers begin to open and show colour as early as mid July, some lasting into the early fall. Canada goldenrod grows across much of the country with a range that extends from the Yukon and Northwest Territories to our southern border and beyond to Florida and California. Its habitat includes a wide variety of open settings. Most often you will encounter it along roadsides, in ditches and in meadows and abandoned fields, but it may also appear in interior grasslands, in forest openings, and among low shrubs. Unfortunately, goldenrod has been fingered in popular mythology, especially in eastern and central Canada, as the source of much allergy-season misery. These striking yellow blooms appear just as our eyes begin to itch and our noses run. As it turns out, however, our scorn for this plant has been misdirected. Canada goldenrod and other goldenrods are, by and large, insect-pollinated species, rarely releasing their pollen to the atmosphere. On the other hand, flowering at almost exactly the same time, is the real culprit – common ragweed (Ambrosia artemisiifolia), which pumps clouds of yellow, highly irritating pollen into the air using wind pollination to spread its genetic material. Fortunately, this annual species of ragweed is virtually unknown in British Columbia. The bottom line is that you can grow goldenrod in your garden with little fear for your health and comfort. In the garden, Canada goldenrod is hardy (zone 0), easy to keep, and a reliable performer. Choose a site in full sun to filtered shade with normal garden soil, neither too rich in organic matter nor overfed with nutrients. Be wary of the partners you choose, because goldenrod spreads readily and will overwhelm a choice garden plant of modest to weak constitution. You may want to rein in its spread using bricks, garden ties or solid plastic edging. Usually, gardeners grow it at the back of a perennial border, but it also shows handsomely rising among medium to low shrubs such as common juniper (Juniperus communis) and tall Oregon grape (Mahonia aquifolia). Its native constitution also suits the species to semi-wild or naturalized situations, such as along a ditch or roadside, or on a bank where its rhizome system spreads to prevent erosion. Goldenrod also grows well in meadows, but be aware that you cannot mow the meadow much beyond late spring or you will cut off the plants’ beautiful blooms-to-be. Goldenrod plants are widely available from garden centres and nurseries, usually as named varieties and hybrids. They propagate easily from fragments of rhizome planted into potting or topsoil, where they should be kept moist until well rooted. Goldenrod germinates readily in spring from fall-sown seed. The plant’s flower clusters can be made into a yellow dye, or when dried, the yellowish-brown flower heads are excellent in floral arrangements. It is said that the inhabitants of America’s original 13 colonies even used goldenrod as a tea substitute to avoid paying taxes to the British Crown before the Revolutionary War. So whatever you may have heard in the past, Canada goldenrod is not a plant to be sneezed at. Try this hardy, attractive native perennial in your garden or natural landscape and enjoy its rich rewards. The following plants are hardy up to the zone number indicated: Canada goldenrod (Solidago canadensis) – zone 0-1 • common juniper (Juniperus communis) – zone 0 • tall Oregon grape (Mahonia aquifolia) – zone 5, possibly hardier An expert on native plants, Richard Hebda is curator of Botany and Earth History at the Royal British Columbia Museum in Victoria.