Orchids in gardens

Sunday, 01 September 2019

Epidendrum species at the Cooroy Orchid Show, August 2019

Last weekend, I attended a delightful orchid show at Cooroy in the hinterland of Queensland's Sunshine Coast. Orchid flowers can often seem almost unreal in their waxy beauty, like exotic butterflies that have arrived from some other world - and it was thrilling to see so many different varieties on display at the show. Orchid-growing can become a deep passion for its enthusiasts who nurture them to perfection and amass large collections, but many orchids can be incorporated into eclectic gardens too. Orchids can be terrestrial (growing in the ground), epiphytic (growing in trees or on logs) and/or lithophytic (growing on rocks). Most can also be grown in large containers, as long as a special orchid potting mixture is used.

Cymbidium orchid in the former garden of my sister Holly in Sydney

Some 10 years ago, I wrote a blog about growing Cymbidium orchids in Sydney, based on the experiences of my sister, who had discovered various secrets about how to keep them looking top notch and getting them to flower! These orchids are in bloom now and a large pot of them can be a most decorative feature. The elegant spikes of bloom last such a long time and come in a multitude of hues.

Dendrobium speciosum in the garden of Nancy and Ted Shaw in Sydney

Also in flower now are some of our local native orchids. One of the best known is Dendrobium speciosum, sometimes called the king orchid or rock orchid. It forms large clumps, with thick 'pseudobulbs' and leathery leaves. The plant flowers in late winter and early spring, with showy racemes clustered with small perfumed flowers ranging in colour from white to creamy yellow or gold. They can be grown on a rock by sitting them on some orchid compost and propping them up with smaller rocks: they will eventually attach themselves to the main rock. They can also be affixed to a tree using an old stocking partially filled with orchid compost in which to anchor the roots. Eventually they will adhere themselves onto the bark. Avoid using a host tree that sheds its bark, such as a crepe myrtle! They need sun to promote best flowering. Another native orchid is Dendrobium kingianum, which forms clumps of pseudobulbs and narrow leaves. Dainty, perfumed flowers in various shades of pink (or, rarely, white) appear in late winter and spring. In its natural habitat it grows on boulders, in rock crevices and on cliff faces, and copes well with dry spells. It can be also be grown in a pot.

Dendrobium nobile cultivar

Dendrobium is one of the largest genera of orchids, with possibly around 1,800 species occurring in the wild in a number of countries. A few years ago, I was given some pieces of variously coloured Dendrobium nobile hybrids, from the garden of a friend's father, who was a keen orchid collector. Dendrobium nobile is an epiphytic or lithophytic plant native to southern China, Taiwan, the Himalayas and Indochina. I tied mine onto trees as outlined for Dendrobium speciosum, where their roots soon took hold, and each spring I am thrilled by the racemes of gorgeous flowers along the thick, curved stems, in colours of white and pinks, some with a distinct dark 'eye'. I grow mine on a Japanese maple tree, which provides sun for the orchid when it loses its leaves in winter, and shelter for it once the leaves return in the warmer months.

Another large orchid genus is Epidendrum, with more than 1,500 species identified. The most commonly seen in Sydney gardens is Epidendrum ibaguense, often called the crucifix orchid, which is found in Central and South America, and the Caribbean. It has long, reed-like stems up to a metre tall, with short, leathery leaves. Clustered flowers of petite red, orange or mauve flowers appear atop the stems through the year. They do best in a sunny spot and can form big clumps over time. They grow in the ground but good drainage is vital.

Zygopetalum cultivar in my garden

A more unusual orchid that grows well in Sydney gardens is Zygopetalum. There around 15 species and a number of cultivars of these evergreen epiphytes from Central and South America. The exotic-looking flowers are fragrant and marked with intriguing spots and stripes, and they appear in flushes up to six times a year. My specimen (pictured) has greenish upper petals marked with maroon and a white flared lower lip with maroon stripes. I grow it in a pot of orchid compost and keep it in full sun during the cooler months then move it into a part-shaded spot in summer. I have seen another species with dark-spotted upper petals and a lower lip with rich purple-hued markings, which is very alluring.

Phalaenopsis orchid cultivar

The gorgeous moth orchids (Phalaenopsis, comprising around 70 species, plus many cultivars and hybrids) are often given as gifts these days, and their stunning flowers continue over a long period indoors in a well-lit location. They mainly come from Asia and New Guinea, and need a tropical or subtropical climate to grow outdoors, mainly being epiphytic. Someone once told me they had succeeded in growing one outdoors in Sydney on a tree, so I have tied a lovely white-flowered one I was given as a birthday present onto the fork of a tree. It has survived winter and I look forward to seeing what happens next!

As with Cymbidium orchids, all these orchids benefit from regular feeding in the lead-up to flowering. It's best to use a propriety orchid fertiliser. Most of the orchids outlined in this blog can be easily propagated by pieces potted up into a free-draining orchid mix. There are a number of different orchid species that can be grown in gardens in Sydney: I would love to hear about some of the others!