Everyone can picture prairie fields glowing with thousands of enormous round, yellow-rayed heads of sunflowers turning to follow the sun. Children and gardeners are drawn to their exuberant growth and friendly presence. Artists such as Vincent van Gogh, Claude Monet and Georges Braque were inspired to paint their muscular stalks, heart-shaped leaves and drooping, seed-laden discs. Birds, chipmunks and squirrels can't wait for the black or grey-striped seeds to ripen. (Give me an apple and a handful of sunflower seeds to chew on in late afternoon and I'm set until dinner.)
But beyond the tall, single-headed, annual sunflowers (Helianthus annuus) are multi-flowered perennials that grow as exuberantly as their one-season relative. You have to be careful, though: some Helianthus, such as the edible Jerusalem artichokes (H. tuberosus) and native species H. atrorubens and H. x laetiflorus are very invasive, sending fat rhizomes or wiry runners underground in every direction. Once entrenched, they are the devil to extricate.
Perennial sunflowers are as tough as nails. Every fall, in our area, armloads of double, yellow pompom flowers spill forward from the sides of barns and the verandahs of older houses. No one knows the proper name of this two-metre-tall perennial: "Been here as long as I can remember—never do a thing for it. My mother called it ‘Golden Glow,'" says a neighbour—which is as descriptive a name as any.
Perennial sunflowers are a hard lot to label, but let's try. A native North American plant, Helianthus decapetalus (Zone 4) is the titular head of a list of varieties; our Golden Glow may be H. d. ‘Flore Pleno' (or perhaps a form of Rudbeckia). ‘Soleil d'Or' and ‘Loddon Gold' are older cultivars, while the related H. x multiflorus ‘Flore Pleno' opens clear yellow blooms as decorative as a dahlia's. All grow from 1.5 to two metres tall and belong in a corner where fences meet, at the back of a broad bed, or up against a barn or garden shed. While perennial sunflowers are self-supporting, their lanky growth and burden of flowers sometimes cause them to incline, a trait you might appreciate if earlier flowers in front are suffering from end-of-season rattiness.
At the back of our yellow border, up against a split-rail fence, grows a nameless Helianthus we call the "chocolate sunflower". Like its kin, it is tall, branching, lanky and late. The surprise comes when you sniff the simple, light yellow flowers that open by the hundreds in September and take in their sweet scent of chocolate and peanuts, reminiscent of a candy bar. If this great, gangly thing leans too far into its neighbours, we lasso the whole mass of growth with a strong rope, pull it back and secure it to the fence.
The newest sunflower in our garden is H. salicifolius ‘Lemon Queen' (Zone 4), a flower that may not “change your life” (as one enthusiastic catalogue writer put it), but a grand, self-supporting, two-metre-tall perennial nonetheless. From late July into September, softly yellow blooms twinkle out from its narrow, dark green leaves. So far, ‘Lemon Queen' appears to be one of those plant-and-forget perennials that need only reasonably good soil and sunshine.
Photo: Heliopsis helianthoides 'Summer sun'