Summer at UBC Botanical Garden means flowers. Some of the most popular summer flowers are salvias (sages) and their relatives. Their colourful, two-lipped flowers are adapted to attracting nectar-feeding pollinators. In Europe and Asia where a number of sages originate, the pollinators are bees and butterflies, but in the New World (the Americas), most sages attract hummingbirds. In an effort to show some of this floral and pollinator diversity, Chris Bale, the horticulturist responsible for the front entrance plantings, has planted a wide diversity of both Old and New World sages in the Entrance Plaza.
Native to the Americas and nowhere else, hummingbirds are the only birds that can truly hover. And because hummingbirds are the primary pollinators for New World sages, the flowers are often red to violet purple (birds are more attracted to these colours) and presented on thin stalks that would otherwise buckle under a pollinator that explores flowers on foot. As a pollination “reward,” salvia flowers produce sugary nectar at the base of a long, narrow floral tube. This can only be accessed by the long, slender bill of a hummingbird or the long tongue of a butterfly. In contrast, bee-pollinated salvias typically have more compact, shorter-tubed flowers that are crowded together on stiff, sturdy stems.
Among the Old World sages, the culinary sage (Salvia officinalis) is probably the best known. Usually grown for its intensely aromatic grey-green evergreen leaves, the purple-blue flowers of this species are exceptionally ornamental as well (and highly attractive to bees). Two selections of this variable southern European native can been seen in the Plaza plantings: ‘Purpurea’, with dull purple new growth, and ‘Berggarten’, with broad, nearly round leaves. The Chinese S. dolichantha is similar in leaf to the culinary sage, but bears velvety lavender-blue flowers on tall stalks and is completely herbaceous. The Balkan sage (S. forsskaolii), another herbaceous perennial, has huge, floppy leaves and tall, strongly branched inflorescences. Flowering as early as June, it can be seen in the Entrance Plaza as well as in the David C. Lam Asian Garden.
New World sages typically flower later at UBC than the Old World species. Although somewhat frost tender, the honeydew melon sage (Salvia elegans) is a welcome addition to hummingbird-friendly plantings. Needing sunny weather and warm temperatures to bear its slender bright red flowers, this bedding sage is popular not only for the hummingbirds it attracts, but also for the deliciously fragrant melon scent of its leaves and stems. Another Central American sage is the hardier, more robust S. guaranitica, the black-and-blue sage. This species is arguably one the most beautiful of all New World sages. By late summer, it stands almost two metres tall, producing a continuous supply of deep blue tubular flowers that are fought over by both visiting photographers and resident hummingbirds. Each flower emerges from nearly black tubular calyx (the calyx is a collective term for the sepals, which normally act as protection for the developing flower, and which, in the case of Salvia species, are fused into a tube). Taking this contrast of calyx and corolla to an extreme is the Andean black-and-white sage (Salvia discolor), which displays striking, white-backed grey leaves and stems. The flowers are a rich black-purple and much like other American sages in the shape of their flowers, but the base of each is nestled in a long, white tubular calyx. When fully in bloom, the flower stalks splay out from tips of the branches waving in the slightest breeze, as if to signal passing hummingbirds. Look for these, as well as other hummingbird, butterfly and bee friendly plants throughout the garden in August.
Submitted by Douglas Justice, Associate Director, Horticulture & Collections, July 27, 2016