Other than those in the fragrance industry, who knew there was a fragrance wheel akin to the color wheel? Indeed, in 1983, a classification system was developed so retailers could suggest similar, yet alternate, fragrances to their customers.
This year’s Great Plant Picks (GPP) selections focus on fragrance. The primary educational program of the Elisabeth C. Miller Botanical Garden in Seattle, Washington, GPP began in 2001. The complete list now covers more than 900 plants and includes bulbs, bam- boos, conifers, ferns, perennials, shrubs, and trees. Each of the last four years of the program has highlighted a different theme: Fantastic Foliage, Fun in the Sun, Made in the Shade, and Small Spaces, Big Impact!
Gardeners love fragrance, many dedicating part—or all—of their gardens to plants with wonderful scents. The GPP team has adapted the use of the fragrance wheel and grouped plants under the following recognized categories: Floral, Spicy, Woodsy, and Fresh. Hence, Plants that Make Scents.
This group is likely the most beloved by gardeners, with roses and daphnes figuring prominently. Richly perfumed GPP rose selections offer a range of sizes and colors to choose from. On the larger side are Rosa Westerland (‘KORwest’)—a modern rose with double orange flowers, R. Graham Thomas (‘AUSmas’)— a David Austin rose with double yellow flowers, and R. ‘Francis E. Lester’—an old-fashioned rose with single white flowers. Each grows to 10, 8, and 15 feet respectively, and to half or equal that in width. If that’s out of proportion for your garden, try one of these old-fashioned roses: Rosa ‘Rose de Rescht’ (double purple), R. ‘Hansa’ (double pink), or R. ‘Fru Dagmar Hastrup’ (single pink), which range in height from three to five feet.
Daphnes are shrubs highly prized for their heavenly floral sweetness. Choose from the variegated varieties, Daphne ×burkwoodii ‘Carol Mackie’, D. odora ‘Aureomarginata’, or D. ×transatlantica ‘Summer Ice’, or those with lustrous green foliage, D. tangutica, D. ×transatlantica Eternal Fragrance (‘Blafra’), or D. ×transatlantica ‘Jim’s Pride’. Several of these evergreen plants begin flowering in April and continue to bloom sporadically throughout the summer or even later. D. odora ‘Aureomarginata’ begins blooming as early as late February and continues through April, while D. tangutica comes on strong in late spring or early summer. All generally stay under four feet tall.
During the gray days of mid-winter in the Pacific North- west fragrant sweetbox (Sarcococca), draws your attention outdoors. These shrubs proffer an intoxicating perfume of sweet vanilla that is never cloying. Sarcococca hookeriana var. hookeriana is the larger of the GPP selections at up to six feet tall, followed by S. confusa and S. ruscifolia (to about five feet); dwarf sweetbox (S. hookeriana var. humilis), is typically less than two feet tall yet spreads horizontally two to four feet in 10 years. Although the tiny white flowers of all these evergreen shrubs are not showy, they yield a delicious scent.
Two hybrid perennials with wonderful aromatic foliage are Geranium ×cantabrigiense and G. macrorrhizum, and their cultivars. All have leaves with a spicy scent and make great groundcovers creating a dense mat with pink, white, or magenta flowers depending on the variety.
Conifers, naturally, hold title to the woodsy scent. Many of the GPP conifers will eventually get large with coast redwood (Sequoia sempervirens) reaching 30 feet in ten years or 100 feet after many decades. Two cultivars of Alaskan yellow cedar (Chamaecyparis nootkatensis), C. nootkatensis ‘Van den Akker’ and C. nootkatensis ‘Green Arrow’ will also grow tall—maturing at around 30 feet—but are like exclamation points in the landscape because of their extremely narrow habit. Even after more than 20 years they have a spread of only five feet or so, allowing them to fit nicely into a smaller space.
Somewhat shorter in height is the coniferous Hollywood juniper, (Juniperus chinensis ‘Kaizuka’) which has an extraordinary growth pattern of upward twisting branches forming a dense, spreading, architectural specimen. Aromatic foliage and glaucous berries are a bonus on plants that are 15 by 10 feet in 10 years.
Lavender, herbs, and other aromatics are a sub- category of woodsy. Fragrant rosemary is beautiful in the landscape as well as valued for culinary use. The hardiest cultivar—some report to Zone 6—is Rosmarinus officinalis ‘Arp’; R. officinalis ‘Blue Spires’, ‘Hill Hardy’, and ‘Salem’ are all hardy to Zone 7. All feature small blue flowers that appear as early as January depending on the weather and cultivar. They take shearing well, making them adaptable for use as hedges or topiary, and the fragrant branches can be used in dried arrangements or cut-flower bouquets.
Citrus, fruity, and aquatic scents are all included in the fresh category. Trillium luteum is a lovely spring ephemeral with yellow flowers, rare among trillium species, which smell like lemon oil. For a fruity fragrance plant either Iris pallida ‘Variegata’ or I. p. ‘Argentea Variegata’. Both have large purple flowers with a scent evoking grape Kool-Aid or grape soda. Variegated foliage on both lend to their appeal after flowering.
Extensive crabapple breeding programs have vastly improved their disease resistance. While all five exceptional GPP crabapple cultivars produce a profusion of white flowers with a pleasing citrus scent in spring, each bears different colored fruit in the fall adding to their multi-season interest: Malus ‘Adirondack’ (red to orange red), M. Red Jewel (‘Jewelcote’, cherry red), M. Sugar Tyme (‘Sutyzam’, red), M. sargentii ‘Tina’ (bright red), and M. transitoria Golden Raindrops (‘Schmidtcutleaf ’, golden yellow).
Clematis montana is an aristocratic vine swathed in late spring with dogwood-like flowers that carry a hint of vanilla, although there is more of a fresh note to the scent than the spiciness of the sweetbox flowers mentioned earlier. Outstanding GPP selections include Clematis montana var. rubens ‘Tetrarose’ with large, almost four-inch, deep pink blooms with a sweet fragrance. Slightly smaller, the lovely pastel pink flowers of C. montana var. rubens ‘Pink Perfection’ blanket the plant and perfume the garden. Clematis montana var. rubens ‘Freda’ produces dark cherry-pink blossoms with a pastel center and a light, sweet fragrance that dances in the breeze. While most montana cultivars reach 30 feet or more in length, ‘Freda’ is more demure at 15 to 20 feet. And finally, the pink flowers of C. montana ‘Elizabeth’ permeate the spring air with a powerful fragrance.
Next time you are shopping for plants, spin that fragrance wheel to any or all of the floral, spicy, woodsy, or fresh scents to bring olfactory wonders to your garden.
For a complete listing of 2014 GPP selections and detailed information on each variety go to www.greatplantpicks.org.