If only it were not such an invasive weed, black locust, Robinia pseudoacacia, might be appreciate for remarkably fragrant and abundant white bloom that resembles that of wisteria. The pinnately compound leaves are about five to ten inches long with rounded leaflets that individually are about one half to three quarters of an inch wide and twice as long. Autumn color is soft yellow. Trees can grow fast to more than fifty feet tall. Furrowed and fissured gray bark makes middle aged trees seem older and more distinguished than they really are. The wood is excellent firewood. All parts are toxic so should be kept out of reach of horses.
Black locust is native to a big area between Pennsylvania, Georgia and Kansas. It was brought to California both to produce firewood quickly, and because it is so appealing in gardens. Modern cultivars and other specie with purplish pink or pinkish purple flowers lack fragrance, but are not invasive.
Mock orange compensates for its lack of flashy color with alluring fragrance.
Remember the smell of the neighbor’s kitchen that met you on the sidewalk as you occasionally walked by when you were young? Whether it was Momma Tomeo’s gnocchi, Mrs. Panagakos’ fresh bread or Mrs. Adam’s black eyed peas, it was so alluring, even from considerable distance. Fragrant flowers may not compare to black eyed peas (mmm), but they certainly can be alluring even without being seen.
Because flowers prefer to be efficient at their work of attracting pollinators, they tend to be either colorful or fragrant, but not both. Those that attract pollinators with color do not need to also use fragrance. Conversely, those that use fragrance to impress pollinators do not need flashy colors. Most fragrant flowers are pale shades of white, and bloom for a short time. However, there happen to a few flowers that are both fragrant and colorful.
Black locust is one of the most fragrant of trees, despite its many other problems. (It is invasive and weedy.) The flowers are bright white, and abundant enough to be quite impressive. Southern magnolia has a distinctive but more subdued fragrance. The flowers are impressively large and bloom randomly through the year, but pale and not very showy among the bold evergreen foliage.
Of the many shrubs with fragrant flowers, mock orange (Philadelphus spp.) has rampant growth with a good display of elegant and remarkably fragrant white flowers. Daphne produces a strongly sweet fragrance with clusters of small pale pink flowers. Both lilac and angel’s trumpet, although very different from each other, have the advantage of impressively fragrant flowers that are quite colorful. Roses offer a better variety of color, but not many are as fragrant.
Wisteria is an aggressive vine with flowers and fragrance like those of the black locust, with all the colors of lilac. Despite the advantage of a longer bloom season, fragrant honeysuckle lacks impressive color.
Earlier in spring, bulbs like freesia, hyacinth, lily, narcissus and some iris bloomed with some of the most fragrant flowers available, in all sorts of colors. Alyssum and flowering tobacco are nice fragrant annuals that bloom longer than most others. Sweet pea may not last as long as weather gets warmer, but compensates with richer and more varied fragrances.
Floral fragrance is likely the primary asset of sweet box, Sarcococca ruscifolia. However, the splendidly glossy and evergreen foliage is as appealing as that of any of the various boxwoods. It is darker and richer green, with orderly arrangement on nimble and arching stems. Individual leaves are small but larger than boxwood leaves, and with pointier tips.
Sweet box blooms during winter, with deliciously fragrant but tiny pale white flowers that are not much to see. They are unlikely to get credit for their impressive fragrance without close investigation for its source. Vigorous plants may produce a few rich maroon berries that contrast delightfully with the rich green foliage. Cut stems work well with cut flowers.
Because it is naturally an understory species, sweet box not only tolerates partial shade, but actually prefers it. Harsh exposure fades its foliage. The dense foliage on wiry stems adapts to low hedging. It is better with alternating cane pruning to remove old stems and promote fresh basal growth. Overgrown specimens respond quite favorably to coppicing. They grow to three feet high.
It may not seem like much to take notice of. Sweet olive, Osmanthus fragrans, resembles glossy privet, but is neither as glossy nor quite as richly green. The dense and evergreen foliage can work about as well for a formal hedge though. It is even better as a small and billowy tree. It gets at least as high as ground floor eaves, and can reach upstairs eaves.
The primary allure of sweet olive is its delightfully pervasive and fruity floral fragrance. Its small and slender clusters of tiny pale white, yellow or gold flowers are mostly obscured by foliage. For those who are unfamiliar with it, the fragrance might be difficult to identify. Bloom is most abundant before and after summer. Sporadic bloom happens at any time.
Because sweet olive is more olfactorily appealing than visually appealing, it works quite nicely as in informal hedge behind prettier plants. It can stay narrow between windows of neighboring homes that are a bit too close together. If enough flowers are available, they might flavor tea and confectionery. A cultivar with variegated foliage is unfortunately rare.
The warm nights between the dog days of summer are ideal for night blooming jasmine, Cestrum nocturnum. That is when it disperses its famously sweet fragrance to attract bat and moth pollinators. A bit of humidity, although unnecessary and locally rare, enhances the permeating nature of the fragrance. Some might find such fragrance to be excessive.
Otherwise, night blooming jasmine is quite modest. Those who experience the powerful fragrance at night may be unable to identify its source while visible during the day. Small floral trusses hold several small and narrowly tubular flowers that are about an inch long. Bloom is greenish white or pallid yellow. Simple evergreen leaves are a few inches long.
Therefore, night blooming jasmine works best in the background of more colorful bloom. It will not mind if other flowers get the credit for its fragrance. With regular watering, night blooming jasmine is happy in unseen areas between buildings, and under high windows that lack views. Aggressive pruning only in early spring promotes blooming new growth. Most plants stay shorter than ten feet. Rare white berries are toxic.
The small trusses of tiny, pale pink flowers of daphne, Daphne odora, really do not need to be too flashy with such powerful fragrance. Actually, the flowers might be considered to be less interesting than the glossy evergreen foliage. The most popular cultivar, ‘Marginata’, has a narrow ivory or pale yellow edge to each leaf. Each leaf is only about two or three inches long. Each domed flower truss is about as big as half of a ping pong ball. Daphne is sometimes grown to compliment and provide fragrance for boldly colorful but fragrantly deficient camellias.
Daphne is unfortunately notorious for being somewhat finicky. It likes rich soil and reasonably regular watering, but quickly rots if soil stays too damp or drains inadequately. The roots are quite sensitive to excavation. Partial shade is no problem. Yet, even the biggest and happiest specimens do not get much more than three feet high and five feet wide, and rarely live more than ten years. Daphne is toxic, and the sap can cause dermatitis.
It is not the ginger that is so popular for culinary purposes, but it is the most popular for home gardens in the West. Kahili ginger, Hedychium gardnerianum, is so vigorous and easy to grow that it has potential to be invasive in ideal situations. Fortunately, it does not produce many of its sticky seeds locally. It therefore migrates primarily by dispersing rhizomes, which are not noxiously fast.
The delightfully fragrant bloom begins late in summer, and will finish soon. As many as forty small pale yellow and red flowers radiate from each cylindrical floral truss. Blooms stand neatly vertical, even if the stems supporting them lean. As cut flowers, they last only for a few days. Deadheading after bloom eliminates unwanted seed (if that is a concern), and unclutters the tidy foliage below.
However, with or without deadheading, the lush foliage is only temporary after bloom. It deteriorates as the weather cools through autumn. Cutting the herbaceous canes to the ground before they get too unsightly will expose some of the thick rhizomes. New canes will grow a few feet tall next spring and summer. On the canes, each leaf extends in the opposite direction of the leaf below it.
Human intervention has sustained the seven species of angel’s trumpet, Brugmansia, since their prehistoric extinction from the wild. They were likely endemic to tropical regions from Venezuela to Chile, and southeastern Brazil. Their extinction was likely a consequence of the natural extinction of animals that dispersed their seed. Most garden varieties are hybrids of the various species.
Angel’s trumpet is either a big shrub or small tree, with rather herbaceous stems. The more popular cultivars can get more than eight feet tall. Cultivars that might get twice as tall are rare. The soft leaves get about six inches long and half as wide. Leaves might get almost twice as long on vigorous growth. Some cultivars have slightly tomentous (fuzzy) foliage. A few have variegated foliage.
Although generally sporadic, and pastel hues of pink, orange, yellow or white, bloom is impressive. The pendulous trumpet shaped flowers are commonly longer than six inches, and half as wide. Double flowers are frilly. Several cultivars are delightfully fragrant, particularly in the evening. All plant parts are very toxic. Plants damaged by frost in winter are likely to regenerate from their roots.
Tony Tomeo 