At the very beginning of the season, lavenders are still in full bloom. No garden, deck or balcony is complete without a lavender. I used to favor the large French hybrids — Grosso and Provence — and they are still splendid herbs, but I have gone back to the more compact English lavenders of my childhood. I especially like the commonly available Hidcote for its indigo-blue flowers. I cut back the fading flower stalks for rebloom in September.
The single most fragrant plant of July is the true lily, not the daylily, but you have to pick the correct types for maximum effect. A class called oriental lilies and their more modern hybrids can be counted on to add a heady fragrance to the summer garden. Look for LO hybrids such as Triumphator and OT or Orienpet hybrids such as Conca D’Or, a buttery yellow, or Black Beauty, a raspberry black variety with heavily bent back, “recurved,” petals. I grow Altari, Scheherazade, Orania and Anastasia, and the perfume coming from that bed is beyond credence.
Another summer treat is the scent of the shrub named clethra or summersweet, which will work in a shade garden where lilies are unhappy. In a sunnier location, butterfly bush will flower for a similarly long time, though it is not as strong as the clethra. This can be a weedy bush that needs cutting back in spring to develop a compact habit. Also, you should cut off faded flowers to promote reblooming and prevent seeding.
In addition to roses, lavender and butterfly bush, the fall garden is ripe with sweet-smelling annuals and tropicals that have reached maturity. These include the snail vine, which will flower happily from seed to vine over the course of a single season, though its flowering will be greatly increased if it is cut back and kept dormant indoors over the winter. Container-grown tuberoses and ginger-lilies are an olfactory knockout, though hardy plants also scent the late-season garden. Sweet autumn clematis blooms in September, an evergreen shrub named osmanthus blossoms in October. Its tiny white flowers are almost invisible, though that doesn’t seem to matter.
The fragrant flowers of winter come and go, relying on periods of mildness that cannot be predicted. Witchhazel is a good example. Some hybrids are more scented than others, and again the acid test is to sniff them in flower before buying one. Green Spring Gardens in Northern Virginia has an excellent collection that is well-labeled. The Chinese witchhazel, Hamamelis mollis, is considered the most powerfully fragrant.
Another shrub named edgeworthia, at its edge of hardiness in Washington, is extremely fragrant when it blooms in February and March. This is about the time a glossy-leafed evergreen named sweetbox blooms. Its little white blooms, the size of rice grains, can perfume an entire garden. Along with a wintersweet, of course.
Right under your nose
The zone of fragrance differs not only by plant, but time of day, so unless you are planting a whole field of lavender or lilies (not a bad idea) you have to place your scented plant close to where you walk and sit. That means by the patio or the screened porch, along the front walk, on a balcony or deck, near the kitchen door or elevated in raised beds or pots.