Few things bring as much pleasure as the sudden rush of perfume of lilac as you turn the corner of a path, or the woodsy turpentine fragrance the thyme sends up as you kneel weeding between paving stones.
Garden fragrances are pleasant enough as happy surprises, but how can a gardener use fragrance more intentionally? In order to understand how to incorporate fragrance as an aspect of garden design, it is essential to know how plants disperse their scent in space and over time.
Scents in Space
Some fragrances drift on the air, others are held in the heart of flowers. Many are released when a plant is touched, a few are exposed only when its roots are torn from the earth. In some cases, different parts of the plant carry drastically different odors. The rambunctious Sicilian honey lily (Nectaroscordum siculum; syn. Allium nectaracsardium, A. siculum) emits a honey aroma from its odd mauve and green flowers, but the rest of the plant reeks of onions.
In order to design effectively with fragrance, it is useful to have plants that emit their fragrances in a variety of fashions. Plants with fragrances that drift on the air are the easiest to place, as their scents are easily noticed from far away. Many of the fragrance drifters are large shrubs, such as winter honeysuckle (Lonicera fragrantissima), witch hazels (Hamamelis spp.) and mock oranges (Philadelphus coronarius).
Consider the prevailing wind direction in positioning these plants—you don’t want the fragrance to drift only to your neighbor’s garage. Try to avoid placing strongly fragrant plants—especially those that disperse their scent on the wind—closer than 10 feet apart. If they are growing too close together, their aromas will be combined in a way that’s not necessarily pleasant. Fill the areas between your scented plants with unscented varieties.
Many of the most popular garden plants for fragrance hold their perfume in the heart of the flower. Roses (Rosa spp.), violets (Viola odorata) and many orchids are examples of this type of fragrance distribution. The flower structure is cupped or tubular, concentrating the flower’s essential oils in the heart of the blossom. Such plants must be located adjacent to paths or grown in containers because their fragrance must be enjoyed at close range.
The array of fragrances found in foliage can be startling. Lemon verbena (Aloysia citrodora), pineapple sage (Salvia elegans) and glory bower (Clerodendrum trichotomum) have scents hardly to be expected from foliage. Lemon verbena and pineapple sage’s aromas match the fruits in their common names. Crush a leaf of glory bower and you’ll be astonished by its strong aroma of peanut butter. Place fragrant-leaf plants near the edges of narrow paths, where you’ll inadvertently brush them as you walk by, releasing their scent.
Scents and Season
The cycle of garden fragrances is one of the most memorable aspects of the gardener’s year. Having something scented in bloom gives a reason to trudge out to the garden even on the most sweltering August evening or frigid December morning.
Many winter flowers distribute their intense perfumes with abandon. Cold shuts down many common scent producers and reduces the amount of pollen in the air, sharpening our awareness of the few fragrances that remain. Snowdrops (Galanthus spp.) may be frigid as an iceberg on cold days, but on warm afternoons they spin their propellers wide and exude a powerful sweet perfume. Sweet box (Sarcococca hookeriana var humilis) also blooms in late winter, with a sweet and spicy aroma. In warmer climates—USDA Zone 7 and above—the winter daphne (Daphne odora) brings hope with its deeply floral fragrance, emitted from tiny white flowers brushed with pink on the outsides.
In spring, it is easy to be overwhelmed by the profusion of aromas. Many of the minor bulbs are sweetly scented to signal their flowering to pollinators. Members of the hyacinth family, such as oriental hyacinths (Hyacinthus orientalis) and grape hyacinths (Muscari spp.) are particularly known for their scents. The profusion of spring-flowering shrubs begs gardeners to cut armfuls of flowers without a moment of regret. Common lilac (Syringa vulgaris) and mock orange (Philadelphus coronaria) are among the most abundant.
The fragrances of summer are evident in flower and leaf. Summer has arrived when a stroll through the kitchen garden yields the soft, milky aroma of squash leaves and the frosty pine fragrance of tomato foliage. One of the most unheralded aromas of high summer is that of coneflowers (Echinacea purpurea cvs.). Coneflowers hold their sticky and sweet fragrance deep within their spiny flowers, releasing it only into the air on the most stagnant summer evenings. Look to older strains, such as ‘Magnus’, as well as newer cultivars ‘Fragrant Angel’, ‘Sunrise’ and ‘Virgin’ for the best perfume.
Late summer brings the taller lilies (Lilium spp.), which envelop the garden in intense clouds of perfume. Bizarrely, some of the most popular lily cultivars are among the least fragrant. ‘Black Beauty’ and ‘Stargazer’ do not represent the potency of lily fragrance. My garden stalwart is ‘Orania’, which has returned for seven seasons in my woodland, despite the heavy soil and lack of organic matter. It kindles gradually with swelling apricot buds that split open to release clouds of fragrance onto the evening air.
As the garden ripens into autumn, garden fragrances become more astringent, with hints of fermenting leaves and decadent autumn fruits. Tropicals are in their full abundance as the nights cool, with angel’s trumpets (Brugmansia spp.) and Mexican sage (Salvia leucantha) rioting in a carnival of spicy-scented bloom.
When choosing plants for a fragrant garden, look for heirloom varieties. Breeders focus on flower size or color, disease resistance or plant size and shape when they select new cultivars. Fragrance often falls by the wayside when they make their crosses and selections. Old-fashioned, open-pollinated varieties are therefore more apt to have a strong scent.
The multi-sensual aspects of plants are what compel many of us to garden. Fragrance interrupts experience, capturing attention and evoking memory. In a plastic world, the smells of plants remind us what it means to be human.