DUSK TO DAWN STUNNERS
PLANTS THAT GO ‘BLOOM’ IN THE NIGHT
NOW I know I’m stating the bloomin’ obvious here, but it’s a fact that most plants in our gardens are at their best during daylight hours.
Many plants need certain daytime temperatures or the correct light levels to stimulate growth or flowering responses.
This is probably at its most obvious as winter turns to spring, when daylight hours grow longer and the air and soil heat up, unleashing flushes of new growth and the always-welcome kaleidoscope of blooms that heralds the warmer seasons.
Therefore, it’d be fair to say that we gardeners plan and plant our gardens for them to be at their best during daylight hours, when their myriads of textures, shapes and colours can be best viewed by us and other humans.
Indeed, many plants will only open their flowers during the day, mainly for pollination and reproduction purposes.
Some that spring to mind are Livingstone daisies, gazanias, daylilies, African daisies and some hibiscus species.
But what happens in our gardens during the night?
Are there some plants that are at their best between dusk and dawn?
And why would they behave this way? It may come as a surprise to some gardeners that many plant species have evolved to “flaunt their wares” during the night time hours.
Why? Well, for many plants, this has come about as a response to the conditions in which they grow, the insects and animals that pollinate their flowers, or a combination of both.
Many plants that inhabit harsh and quite arid regions on this planet, such as many cacti and succulents, will flower at night to conserve valuable moisture which is needed in larger quantities whilst blooms are being produced.
At this time, they will often release copious amounts of fragrance in order to attract nocturnal pollinators to their vicinity.
An interesting observation regarding night-flowering plants is that most will only have white, cream or light green-coloured blooms, as these are best seen by nocturnal creatures with vision tuned to these wavelengths.
Night-time pollinators are mainly insects such as moths and beetles (e.g. hawk moths, scarab, chafer and Christmas beetles), and animals such as possums, bats and flying foxes.
Of the many Australian native plants that attract night-time pollinators with fragrance, none are better than our ubiquitous gum trees (Eucalyptus and Corymbia species).
One has only to observe the squadrons of flying foxes commencing their night-time sorties at dusk to realise that they are a major pollinator of many of our native trees, mostly the flowering gums.
Another Aussie native tree that releases its delightful fragrance from creamy-yellow flowers at night is the native frangipani, Hymenosporum flavum.
It’s mostly pollinated by a variety of moth species.
Many exotic species of plants will only bloom at night, many with an extra burst of fragrance from their light-coloured blooms.
One stunner, highlighted to me this week, goes by the very apt common name of “Queen of the Night” (Epiphyllum oxypetalum).
Hailing from Southern Mexico through to South America, this wonderful plant produces large, highly fragrant, almost pristinely-white blooms that only last one night, for only one night a year.
The blooms attract nocturnal pollinators such as hawk moths, and sometimes small bats, with their fragrance that has been likened to that of gardenias or magnolias.
Growing epiphyllums requires a container with a free-draining, acidic potting mix, some shade, and some support for their sometimes gnarled and twisted flattened stems and leaves on which to grow.
(Many thanks to Helen C for sending me some images of her gorgeous plants this week.)
You may be interested to know that the dragon fruit, Hylocereus undatus, is a very close relation to the Queen of the Night, and it also blooms once only, at night.
Many other plants are at their best during the after-dusk hours.
One of my favourites is the Angel’s trumpet (Brugmansia species).
Whilst the flowers of this tall shrub/small tree are open both day and night, they increase and release their heavenly fragrance at night to attract moths for pollination.
It’s hard to describe the wonderful olfactory experience of these plants on a warm, still summer’s night.
It’s an interesting fact that many plants in the same family as Angel’s trumpets, that is, Solanaceae, are most fragrant at night.
It’s also worth noting that many plants in this family are poisonous and weedy, such as the night-scented jessamine, Cestrum nocturnum, so be careful if you decide to grow these plants in the local region.
A great alternative to Cestrum nocturnum is Nicotiana, the tobacco flower, which is still in the same family, strongly scented, but not regarded as weedy.
There are cultivated varieties of Nicotiana available on the Australian nursery market.
Other plants that tend to flower at night, or release their fragrance at that time (or both) include Murraya paniculata (orange jessamine), many gardenia varieties, evening primrose, wisteria floribunda, and many varieties of cacti and succulents.
Garden Cuttings – Have you any interesting plants you’d like others to know about? Send me an email with images to wellsleyhorticultural@gmail.com, or message me on FaceBook at Wellsley Horticulture.