Night Blooming Jasmine

These dinky flowers disperse grand fragrance.

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.

Pink Jasmine

These pale, inch-wide, star shaped flowers of pink jasmine may not be much to look at, but are remarkably fragrant.

As winter turns to spring, pink jasmine, Jasminum polyanthum, blooms with abundant, loose trusses of small but very fragrant star shaped flowers. The flower buds that are initially deep pink open to soft pink, and then fade almost to white. Light shade inhibits bloom and limits foliar density, but does not prevent the wiry vines from climbing to twenty feet or so. The dark green leaves are compound with five or seven leaflets. Pink jasmine is one of the few vines that can climb lattice and light trellises without tearing them apart like wisteria and so many other popular vines eventually do. Even if it escapes confinement and gets into trees or onto roofs, it does not get too far to be pruned back within bounds.

FLORAL FRAGRANCE IN THE GARDEN

The most fragrant flowers are generally smaller and less colorful than less fragrant flowers. This angel’s trumpet is an exception.

Attracting pollinators is serious business for flowers that do not rely exclusively on wind for dispersion of their pollen. Many flowers attract pollinators with flashy color. Some reward their pollinators with sweet nectar. Many prefer to use fragrance. Most flowers use a combination of two or more of these tactics.

Fragrances are designed by the flowers that use them to appeal to the discriminating taste of specific pollinators. Most are sweet. Some are more perfumed. A few are even quite objectionable to people because they are tailored to flies. Fortunately, flowers with foul fragrances are rare in gardening.

The most fragrant flowers are often less abundant than flowers that rely on wind for dispersion of their pollen, or less colorful than flowers that rely on visual appeal to attract pollinators. Yet, the fragrant flowers of wisteria vines and lilacs are both profuse and colorful. The surprisingly big and fragrant flowers of ‘Charles Grimaldi’ angel’s trumpet are bright yellow.

Mock orange (Philadelphus spp.) conforms to the stereotype of fragrant flowers a little bit better, with somewhat small white flowers that are incredibly fragrant. The small pale pink flowers of daphne are even less impressive and nearly hidden among their foliage, even though their fragrance can not be ignored. The sweetly fragrant flowers of Japanese honeysuckle vines are abundant but not too colorful. Star jasmine vines likewise bloom fragrantly and abundantly, and their bright white flowers contrast better against their glossy green foliage.

Night blooming jasmine is not appealing enough for prominent placement, and is not even fragrant during the day, but will be unbelievably fragrant on warm summer nights. Just as fragrances appeal to specific pollinators, nocturnally fragrant flowers specifically appeal to insects or bats who are active at night.

Freesia, hyacinth, lily,narcissus and some types of iris are very fragrant as well as colorful now that they are blooming for early spring. It is unfortunate that their flowers do not last long, and that there are not any comparable flowers later in the year. The same annual sweet peas and stock that bloom about now can be planted again later for autumn bloom. Sweet peas are easiest to grow from seed. Stock is easiest to grow from cell packs, and since it is actually perennial, sheltered plants can survives through warm summer weather to bloom again in autumn. Annual sweet alyssum can bloom anytime while the weather is warm.

Fragrant Flowers Often Lack Color

Unremarkable flowers can be remarkably fragrant.

It is presumptuous to believe that all the fancy breeding that is done to enhance the characteristics of flowers necessarily ‘improves’ them. Breeding only makes flowers more appealing to those who enjoy them in their gardens. Most flowers were already quite efficient for their intended function in their respective natural habitats long before humans started tampering with them. As far as flowers are concerned, they only need to get pollinated.

Some flowers use flashy color or patterns to be visually attractive to pollinators. Others use fragrance to be olfactorily appealing. Small but profuse flowers that are neither colorful nor fragrant have given up on insect or animal pollinators, so instead rely on the wind to disperse their pollen.

Not many flowers are both remarkably colorful and remarkably fragrant like freesia, lilac and wisteria were earlier in spring. Lily and bearded iris are of course very colorful, but not all types are fragrant. The big and bold flowers of cereus cactus, moon flower and angel’s trumpet are only fragrant because they bloom at night, and rely on nocturnal  pollinators who benefit from a bit more guidance in the dark.

Many fragrant flowers are somewhat showy, like gardenia, star jasmine, pink jasmine and honeysuckle. (However, gardenia are almost never healthy and showy locally.) Many of the most reliably fragrant flowers are really not much to brag about. Pittosporum tobira, Pittosporum undulatum and sweet osmanthus are known more for the appealing evergreen foliage than for their small and nondescript flowers. The flowers of sweet osmanthus may actually be difficult to find amongst the obscuring foliage. Night blooming jasmine is sometimes planted around corners or in the background because even the foliage is not too appealing, although the powerful candy-like fragrance is a favorite for warm evenings.

Fragrant flowers can be annuals like sweet alyssum, bulbs like hyacinth, or perennials like tuberose. Woody plants with fragrant flowers can be vines like stephanotis, shrubs like mock orange (Philadelphus spp.), or trees like Southern magnolia. Some have brief bloom seasons, while others bloom for quite a while.

Daphne

Perhaps fragrance could be more colorful.

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.

Angel’s Trumpet

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Powerful fragrance combines with docile color.

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.

Fragrant Flowers Have Ulterior Motives

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Demure daphne bloom is richly fragrant.

Many who enjoy gardening appreciate fragrant flowers. Many grow particular flowers specifically for their fragrance. Yet, not many consider why so many flowers are fragrant. Plants can not enjoy their own alluring floral fragrances any more than they can enjoy their own delightful floral colors and forms. They do not expect people to enjoy their bloom either. Human appreciation is incidental.

Floral fragrance is merely intended to attract pollinators. Flowers are inanimate, so rely on either wind or animate pollinators to exchange their pollen among other flowers. Animate pollinators are mostly insects, but may be birds, bats or other animals. Flowers do what they must to attract their preferred pollinators. Many use color and floral form. Many use fragrance. Some use both tactics.

Flowers that use both color and fragrance to attract pollinators are mostly endemic to densely forested ecosystems. There is more competition for pollinators within such ecosystems than there is within ecosystems of sparser vegetation. Otherwise, fragrant flowers are generally not as colorful as those that are not as fragrant. Likewise, the most colorful flowers are generally not so fragrant.

Angel’s trumpet is striking in bloom because the flowers are so large. Wisteria and lilac that bloomed last spring were spectacular because they were so profuse. The pastel hues of their blooms are no problem that their fragrance does not compensate for. Pink jasmine and mock orange are about as fragrant, even if their color range is more limited. Star jasmine is not always so profuse.

Pittosporum tobira and Pittosporum undulatum are even less visually impressive in bloom, but can be surprisingly fragrant. The tiny but richly fragrant flowers of sweet osmanthus, sweet box and night blooming jasmine are so obscure that other bloom is often credited with their fragrance. As the name implies, night blooming jasmine is powerfully fragrant after sunset during warm weather.

Freesia, hyacinth, narcissus, lily and some bearded iris are both colorful and very fragrant.

Dragon Lily

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Dragon lily is striking and stinky.

Dracunculus vulgaris make a sinister impression by botanical name alone. Common names include dragon lily, dragon arum, dragonwort, black dragon, snake lily, stink lily and voodoo lily. That makes it sinister enough to be compelling. Although rare in nurseries, dormant tubers are available in season by mail order. Alternatively, established colonies happily share a few dormant tubers.

Dragon lily is quite easy to grow. It appreciates rich soil and regular watering, at least until it gets established. Once settled in, it might be satisfied with only monthly watering until it goes dormant in late summer. Because it prefers humid climates, it wants shelter from wind here, and may like a bit of partial afternoon shade. It is so adaptable that it unfortunately naturalized in some regions.

The fragrance of dragon lily attracts insect pollinators that are drawn to dead animals. Those of us who enjoy unusual plants find it amusing. Everyone else thinks it stinks. Blooms that produce the fragrance are spectacular, with a big and flared purplish red spathe around a slender black spadix. They may stand nearly three feet tall, among lightly blotched and deeply lobed palmate leaves.

Stinky Flowers Serve Their Purpose

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Some beetles like stinky flowers too.

From a human perspective, flowers should not be stinky. They should be pretty and colorful, and perhaps delightfully fragrant. Many flowers in landscapes and home gardens actually are. After all, they are grown for their appealing bloom. Many plants that provide only foliage produce wind pollinated flowers. They are not particularly pretty, colorful or delightfully fragrant, but not stinky either.

Flowers do what they must to pollinate each other. Since they are inanimate, they rely on pollinators or wind to disperse their pollen. Those that rely exclusively on wind produce an abundance of very fine pollen, but waste no effort on attracting pollinators. All other flowers use customized combinations of colors, patterns, textures, fragrances and flavors to attract their preferred pollinators.

There are all sorts of pollinators. Bees are the most famous. There are many other insects too. Hummingbirds and butterflies are very popular. Bats do their work at night while no one is watching. Of all the pollinators though, flies are likely the least popular. Many of the flowers that produce fragrance to attract them are not exactly popular either. Alas, fly pollinated flowers are stinky flowers.

Stinky flowers are naturally uncommon. Apparently, not many flowers want to rely on flies. Stinky flowers are even more uncommon in home gardens and landscapes, for the obvious reason. Paw paw and carob production relies on stinky flowers. A few of the various arums grown for dramatic bloom are stinky too. Philodendron bloom is quite stinky, but very rare among foliar houseplants.

Pear and hawthorn do not rely on flies, so are only incidentally and mildly stinky.

Fortunately, stinky flowers are not often a problem. Paw paw trees are rare here. Carob trees bloom somewhat briefly. If philodendrons bloom at all, they produce only a few flowers which can get pruned off. Regardless, fragrances of stinky flowers are generally not as strong as appealing floral fragrances. They neither disperse as efficiently, nor linger as long. Some are too faint to offend.

Horridculture – Stinky Flowers

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Rhody was not impressed, and he is an expert on fragrance.

Dracunculus vulgaris – dragon lily. It was featured in the gardening column for next week, both as an illustration for the main topic, and as the ‘highlight’ species. It is as unappealing as the name and the pictures suggest, but it sure is interesting. It has several more equally unappealing common names. We know it as ‘death arum’ because that is the first name we came up with.

Besides, it smells like death. Yes, it stinks. It does so to attract flies for pollination. Actually, it attracts quite a few annoying insects. I can not explain why, but insects who congregate around stinky flowers are as unappealing as the fragrance that draws them. They are certainly very different from the appealing bees and butterflies who pollinate flowers with appealing fragrance.

The first of these death arums mysteriously appeared in the garden of a colleague several years ago, and promptly multiplied by both seed and disbursement of tubers. There are now a few expansive colonies that continue to expand. Cutting down the foliage does not slow them down much. The fragrance, which is not too bad individually, is getting to be bothersome collectively.

My colleague brought me one of the tubers to confirm the identity. I got a picture of it since it was here, but then did not know what to do with it. I did not want to toss it aside into the forest like I do with so much other greenwaste. It could have grown into a problem. I did not want to discard it either, since it was viable and healthy. So, I canned it and put it aside in the nursery.

This is the result. It is not as stinky as I expected it to be. I still do not know what to do with it.

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These unidentified beetles that I had never noticed here before arrived promptly for the stinky bloom.