Looks can be deceiving. Night blooming jasmine, Cestrum nocturnum, does not look like much. It looks even less interesting in the darkness of night. However, its floral fragrance on warm summer nights is famously sugary and intense. Some might find it too intense. Nocturnal moths and bats are its preferred pollinators, so it is not fragrant during the day.
Because of its mundane appearance, night blooming jasmine is good in the background. It tolerates a bit of partial shade, so can be happy close to fences and buildings. It works well witin narrow spaces between houses and below high windows. Where winters are cool, it needs shelter from frost. It appreciates somewhat regular watering and rich soils.
Mature night blooming jasmine rarely grows higher than first floor eaves. It is quite easy to maintain lower, particularly if pruned aggressively after winter. Its narrow floral trusses suspend several small and narrowly tubular flowers. Individual flowers are about an inch long, and greenish white or pale yellow. Simple evergreen leaves are a few inches long, and narrow.
Many flowers are fragrant. Many are colorful. Several are both. The majority, though, are neither. That is because flowers use fragrance and color only to attract pollinators. Most flowers rely on wind for pollination, so do not need to attract pollinators. Such flowers are not so conspicuous, though. Fragrance and color are much more prominent and popular.
Most prominently colorful flowers are not very fragrant. They do not need to be. Flowers can use one technique or the other, fragrance or color, to attract pollinators. They do not need to waste resources on redundancy. Hibiscus, dahlia, sunflower, daisy, camellia and canna all lack floral fragrance. Yet, they efficiently attract pollinators with their floral color.
Most prominently fragrant flowers are similarly not very colorful. Night blooming jasmine, sweet box and sweet osmanthus produce small white flowers. Yet, they efficiently attract pollinators with their floral fragrance. Gardenia is more colorful only because its blooms are larger. Star jasmine is more colorful only because its blooms are much more profuse.
Victorian box and mock orange also bloom with fragrant but subdued flowers about now. Most angel’s trumpet blooms with fragrant but impressively large flowers in pastel colors. Hyacinth, narcissus, freesia and lily flowered both fragrantly and colorfully last spring. So did wisteria and pink jasmine. Daphne flowers are diminutive but fragrant for next winter.
Modern roses and some bearded iris are not as fragrant as some old cultivars. Many lack fragrance altogether. This is generally because fragrance had not been a priority of their breeding. Both roses and bearded iris now bloom with bolder flowers, which last longer. Roses bloom for a longer season, instead of only once. Fragrance was the compromise.
Floral fragrances are as diverse as the pollinators that they attract. This is because, like floral color, they appeal to particular pollinators. A few appeal to a single specific species of pollinator. Several flowers disperse their fragrance at night for nocturnal moths or bats. Most flowers, though, are receptive to pollinators that they do not intentionally appeal to.
Several species of Phlox are native California wildflowers. Yet, the more popular garden phlox, Phlox paniculata, is native only east of Kansas. It can self sow where it gets water, and is naturalized in the Pacific Northwest. It prefers rather rich soil and sunny exposure but is not very discriminating. A bit of partial shade might promote taller stems for cutting.
Mature garden phlox can be as tall and wide as three feet. Some modern cultivars stay a bit more compact. Dense panicles of small flowers may be as wide as six inches. Bloom is most commonly white, but may be pink, red, lavender or pastel orange. It is a splendid cut flower, with an alluringly rich fragrance. Bloom might continue for a month of summer.
Garden phlox is deciduous, so all canes die to the ground for winter. Mature colonies are then easy to propagate by division. Similarly, feral specimens that appear where they are unwanted are easy to relocate. Garden phlox can perform nicely in proportionately large pots and planters. It is uncommonly available from nurseries, but grows easily from seed.
Lineage can be difficult to identify. Most popular cultivars of angel’s trumpet, Brugmansia are hybrids. Many are hybrids of hybrids. Almost all are consequently identifiable by only their genus and cultivar names. They usually lack species names. Their original species were likely native from Venezuela to Chile or southern Brazil. No one knows definitively.
Angel’s trumpet is a big bushy perennial. Its trunks may be as substantial and persistent as those of small trees. Most popular cultivars can grow higher than eight feet. A few rare cultivars should grow larger. Leaves are about six inches long and half as wide, or larger on vigorous stems. Some cultivars have slightly tomentous foliage. A few are variegated.
Bloom is sporadic while the weather is warm, and can be profuse in phases. Flowers are commonly longer than six inches and wider than three. Most are very pendulous. Double flowers are quite frilly. The floral color range includes pastel hues of yellow, orange, pink and white. Several cultivars are nicely fragrant. All parts of angel’s trumpet are toxic.
Aroma and fragrance in a garden have two very different natural purposes. Aroma, which is foliar, repels insects or animals who may otherwise eat such foliage. Fragrance, which is floral, attracts insects and animals to pollinate such flowers. Aromatic foliage ironically appeals to people, particularly as herbs. The appeal of fragrant bloom is not so contrary.
With few exceptions, fragrant bloom is an asset to a garden. Although its primary function is to attract pollinators, people enjoy it also. The few exceptions are flowers that produce fragrances that are unappealing to people. For example, several species of Arum attract flies for pollination. Therefore, they exude foul fragrances that appeal specifically to flies.
Fortunately, most pollinators prefer fragrances that people also enjoy. Many of the richest and strongest fragrances appeal to a broad range of pollinators. Some more refined and distinctive fragrances attract specific pollinators. Fragrant bloom is most fragrant when its preferable pollinators are most active. A few bloom at night for their nocturnal pollinators.
Fragrant bloom is generally not as colorful as bloom that is less fragrant. It does not need to be. Color is merely another visual means with which to attract pollinators. Flowers that are both fragrant and colorful are mostly from competitive ecosystems. Angel’s trumpet is both spectacular in bloom and splendidly fragrant. Yet, its floral color is limited to pastels.
Some of the most fragrant bloom is that of bulbs that bloomed early last spring. Hyacinth, narcissus, freesia, lily and some bearded iris are both fragrant and colorful. Wisteria and pink jasmine are vines that were also fragrant and colorful last spring. Star jasmine is not quite as colorful, but is as fragrant, and still continues to bloom. So does angel’s trumpet.
Warming summer weather will now promote more fragrant bloom, even if it is not colorful. Pittosporum undulatum exudes an almost citrusy fragrance. Pittosporum tobira is slightly buttery. Sweet osmanthus and sweet box are proportionately more fragrant while young. Night blooming jasmine might be the sweetest of all, but more so during warm evenings.
Flowers are only as colorful or fragrant as they are to attract pollinators.
When the garden is full of bloom, we do not like to think that flowers have an agenda. All their colors and fragrances seem to be displayed merely for our benefit. Who really wants to know that procreation is their real priority; that all their efforts are merely to get pollinated to make seed for the next generation?
Because flowers are not mobile like animals and insects are, they need to rely on wind or pollinators to deliver their pollen to other flowers. Flowers that are more reliant on wind for pollination are not much to look, since they do not need to advertise. The wind needs no incentive to blow. Wind pollinated flowers are instead abundant and productive, to disperse as much of their light pollen as possible.
Flowers that need pollinators need to advertise. They offer all sorts of attractive colors, fragrances, nectar and pollen to attract their particular preferred pollinators. For example, those that exploit the services of hummingbirds appeal to their discriminating taste with sweet nectar in tubular flowers that are mostly in colors that hummingbirds like, orange or red.
All the variety among flowers is designed for the variety of pollinators that they employ. Flowers that rely on nocturnal moths are large and pale, often with infrared patterns (that people do not see) to be visible in moonlight to moths drawn to their sweet fragrance. The offensive fragrances and textures of fly pollinated flowers are delightful to flies. Many flowers appeal to multiple pollinators.
Bees are of course the busiest of pollinators, as they collect nectar and pollen to make honey. They visit any flower they encounter, but prefer those that make abundant and dense pollen that they can carry away. They are very fond of the many different fruit trees; such as apple, pear, apricot, cherry, plum and all their relatives, as well as citrus. They also dig eucalyptus, wild lilac (ceanothus), hebe, firethorn, bottlebrush, honeysuckle and roses.
The difficulty for bees is finding a constant supply of flowers. As apple and pear trees finish blooming, bees want to start visiting other flowers. Bees like a variety of just about any of the annual flowers, particularly pincushion flower, cornflower, snapdragon, foxglove, sunflowers, poppies and lupines. With a good mix, something should always be blooming. Bees are also very fond of catmint, ajuga, thyme, rosemary, penstemon, lavenders and the many salvias and sages.
Those who want to attract bees to the garden should therefore plan for a good mixture of flowers that bees like, so that there is always something to keep the bees happy. Many of their favorite flowers that may not seem very colorful to us use ultraviolet patters that are quite flashy to bees. The choices are not always so obvious.
However, those who do not like bees or are allergic to bee stings, should avoid an abundance of flowers that will attract them. Unfortunately, there are no flowers or plants to repel bees. Also, the coniferous (cone bearing) evergreens and many other wind pollinated plants that are less attractive to bees produce abundant light pollen that is so problematic for allergies.
It is certainly a star within many gardens, but it is technically not a jasmine. Star jasmine, Trachelospermum jasminoides, is actually closely related to Plumeria. Its floral fragrance can be comparably rich with copious bloom, but is distinctly vanillish. Bloom is abundant for late spring and early summer. Sporadic bloom can start early and continue to autumn.
Without bloom, the distinctly glossy foliage is handsome alone. Individual leaves are not much longer than two inches, and not much wider than one. Their deep green foliar color and lustrous sheen almost seem artificial. Pruning or any disturbance of foliage or stems releases caustic and toxic sap. Twining vines ascend by wrapping around their supports.
Star jasmine can get two feet deep as a ground cover without support. It requires pruning to prevent it from overwhelming shrubbery or climbing into trees. It also requires frequent pruning around its edges. As a climbing vine, it grows fast to ten feet high, and can grow much higher a bit slower. It can become a neatly shorn faux hedge on a chain link fence.
Meriwether Lewis of the Lewis and Clark Expedition encountered the western native mock orange, Philadelphus lewisii, in 1806, and gave it his own name. It inhabits an extensive range that reaches from the northern Sierra Nevada to southern British Columbia to western Montana, but is somewhat sporadic within its natural range. It is the state flower of Idaho, and is commonly planted in state, national and even some county parks within its range and throughout the rest of California.
Partial shade is not a problem for mock orange, but full sun exposure promotes more abundant bloom. The simple, strikingly white flowers that bloom in spring are less than two inches wide with only four petals. However, their remarkably rich orange fragrance is unexpectedly powerful. The two inch long, forest green, deciduous leaves on arching limber stems are a nice backdrop. ‘Goose Creek’ has double flowers.
Because regular pruning or shearing of outer growth inhibits bloom and compromises natural form, mock orange is best where it has plenty of space to grow wild, or at least where the upper canopy can spread out naturally if the lower canopy gets pruned away to form a small tree with multiple trunks. After bloom, older deteriorating stems can be pruned out, to favor newer stems emerging from the base. Overgrown plants can be cut to the ground in winter, and will regenerate over the following summer to bloom in the second spring. Mature mock orange gets nearly ten feet tall and broad.
Floral fragrance attracts insect pollinators. Foliar aroma repels insect pathogens. It might repel other herbivores also. For organisms that lack olfactory perception, plants certainly make productive use of it. Fragrant flowers are as attractive in home gardens as they are to pollinators in the wild. However, aromatic foliage has the opposite of intended effects.
In other words, aromatic foliage is popular within home gardens because of its aroma. Its effort to be repulsive to some insects and herbivores makes it attractive to people. Some aromatic foliage has culinary or herbal application. Actually, almost all herbs are notably aromatic, with corresponding flavors. Mint, chive, thyme and sage are popular examples.
Window boxes became popular in ancient European towns because of aromatic foliage. Where garden space was scarce, they were convenient planter boxes for growing herbs. Also, prior to window screens, they sustained aromatic foliage that repelled mosquitoes. Trailing rosemary, ivy geranium and nasturtium are still very traditional accompaniments.
Rosemary has both culinary and aesthetic application. Culinary cultivars exhibit the best flavor. Landscape cultivars are either trailing or more densely shrubby. Some cultivars of fennel are similarly better for either culinary or landscape application. Bronze fennel has become popular for both. Varied lavenders are more popular as home garden shrubbery.
Native bay is very aromatic when its foliage is disturbed, but is not culinary bay. It is a big and obtrusive tree that is proportionate only to large landscapes. Culinary bay is another smaller species that is more proportionate to home gardens. Also, it has a distinct aroma. Incense cedar is another very aromatic native tree, but is quite rare within home gardens.
Most aromatic foliage can not exude its aroma like fragrant flowers exude their fragrance. Most does so only when disturbed. Some, such as that of many conifers and eucalypti, is beyond reach. It is therefore easy to dismiss within some landscapes. Lavender, lantana, diosma, rockrose and salvia stay within reach. Warmth and humidity amplify their aroma.
Bloom should be most abundant during late spring and summer. Within this mild climate though, it often continues sporadically through autumn. Japanese honeysuckle, Lonicera japonica, is presently blooming nicely in some areas. Its trusses of ribbony creamy white flowers fade to pale yellow. Although unimpressively colorful, they are alluringly fragrant.
Japanese honeysuckle here is almost exclusively Hall’s Japanese honeysuckle. It might be recognizable by a cultivar name of either ‘Hall’s Prolific’ or ‘Halliana’. Some botanists consider halliana to be a variety rather than a cultivar. (Variety names are neither quoted nor capitalized like cultivar names.) ‘Purpurea’, with dark but not purplish foliage, is rare.
Japanese honeysuckle, like star jasmine, is a vine that can be a ground cover. As a vine, It can climb more than thirty feet high. Unfortunately, it sometimes overwhelms shrubbery and small trees. Its twining stems can constrict the stems of other vegetation that it wraps around. As ground cover, it can get three feet deep. Leaves are two or three inches long.
Tony Tomeo 