Flowers of the night

Sunday, 01 March 2015

Brugmansia flowers are fragrant at night

In an anthropocentric way, we (or at least I) often think flowers are beautiful for our benefit: to delight us and to decorate our gardens. In fact, if course, the sole purpose of a flower is to attract pollinators in order that it can produce offspring for future generations of plants. Whilst birds, butterflies, flies, beetles and bees do their work of pollinating during the day, moths, bats and some types of beetles work the night shift. There is a whole group of night-blooming and night-fragrant plants that has evolved to attract these creatures.

I have often dreamed of creating a small garden of such plants to enjoy on a balmy summer evening. Books have been written on the subject, including the delightful The Evening Garden by Peter Loewer, where suggestions are given for flowers that only open at night and those who exude their strongest perfume in the evening hours. Most night-blooming plants have white, cream or pale yellow blooms, in order to be found by their pollinators - others have scent to lure them - and some have both. The pale flower colours glow in the moonlight, adding to the enchantment of a night garden.

Flower of Ipomoea alba, the moonflower

I envisage a small area enclosed by trellis, on which would grow the moonflower vine, one of the most exotic of the night bloomers. I first read about the moonflower (Ipomoea alba, pictured left, photograph by Lyn Cox) years ago, in a gardening novel by Beverley Nichols, Sunlight on the Lawn, where he described seeing the blooms during his travels in India - climbing around the ruins of a Hindu temple - and in Jamaica - tumbling over a white wall. He described the flowers as like 'the simple wild convolvulus of the hedgerows, but they had a span of three or four inches, and their whiteness was faintly phosphorescent, with a hint of the palest green, such as one glimpses in the fire of a glow-worm. Their fragrance ... suggested a blend of incense and the peel of fresh lemons'. He became obsessed with getting seeds of the vine to grow in his English garden and eventually succeeded in getting the plant to flourish and seeing some of the exotic blooms unfurl at night. The huge blooms actually open before one's eyes over the period of a few minutes at twilight and collapse at dawn. In its native habitat in tropical America, the vine is perennial, growing to 20m! In cooler areas it is usually grown as an annual. It is closely related to the dreaded morning glory vine so I hope it isn't as rampageous as that!

Nicotiana sylvestris

In my hypothetical night garden, I would also grow Nicotiana alata (ht 1 m), an ornamental tobacco with tubular flowers of white, red or pink that open towards evening and have a sweet scent. The stately Nicotiana sylvestris (ht 1-1.5 m, pictured left) is a species with a rosette of huge furry leaves and a very tall spire clustered with white trumpet-shaped flowers that are open by day and night, but are especially fragrant at night. I have grown this plant on and off for years - it is a bit hard to place in a garden, as it needs to be on its own to be fully appreciated, rather than hemmed in by surrounding plants. It self-seeds madly. Flowers of modern hybrid Nicotiana have been bred to stay open all day, but most of the species are night-blooming.

Epiphylum oxypetalum

In a pot in my night garden, I would also grow an orchid cactus: Epiphylum oxypetalum, an epiphytic cactus from tropical and subtropical America, often known as queen of the night. It is a scrambling succulent to 6m that can be trained up through small tree or else grown to cascade from a hanging basket. They apparently do better when the roots are constrained by a container. The stems are branched and flattened, and from the edges of these stems, spectacular, strongly scented flowers appear at night about once a month during summer and early autumn. There are many members of the cactus family that flower at night, including other Epiphyllum species of various colours. They are definitely worth hastily arranging a party to see when in bloom!

Mirabilis jalapa

Another plant with flowers that opens only in the late afternoon or evening is the 4 o'clock or marvel of Peru (Mirabilis jalapa, pictured left), a subshrub from tropical America growing from a tuber and reaching about 1 m in height, smothered with scented tubular flowers of red, magenta, yellow, white or rose - many striped or dashed with other hues. I remember it growing robustly in my mother's Blue Mountains garden. If I included this plant in my night garden, I would keep it in a pot as they can become invasive and difficult to remove eventually. The old-fashioned night-scented stock (Matthiola longipetala subsp. bicornis) is a bedraggled-looking non-entity by day, but by night its pink, mauve or purple petals perk up and exude a delicious perfume, worthy of inclusion in a night garden.

Eucharis x grandiflora

Plants that are open day and night, but which have a strong, sweet fragrance at night to lure pollinators, include the angel trumpet Brugmansia (pictured at the start of the blog), which can grow to a small tree; shrubby night jessamine Cestrum nocturnum with tiny but highly perfumed flowers; white-flowered Gardenia thunbergia; climbers Hoya and Stephanotis floribunda; and the bulbs Gladiolus tristis (with creamy-yellow flowers) and Eucharis x grandiflora, pictured above, with flowers like pristine white daffodils. There are apparently even bromeliads and daylilies that are night-fragrant. The phenomenon of night fragrance explains why some plants said to be 'perfumed' don't seem to be when smelled during the daylight hours! It's definitely worth having a sniff around your garden in the evening to hunt out night-bloomers.

My night garden remains a dream, but with moonflower seeds now in my possession (I recently had the good fortune to find a moonflower vine growing in the inner-west of Sydney, and to obtain some seeds, in one of those serendipitous happenings that make gardening so eternally fascinating), I am one step closer to it!