We have two stunning Australian dendrobiums for the next two days. The first is Dendrobium gracilicaule, a species that is filling the greenhouse with its scent of coconut.
Dendrobium gracilicaule produces slender pseudobulbs up to 70cm long (in our greenhouse) and generous multiple spikes of slightly nodding flowers. The flowers are unusual for being plain yellow inside but beautifully spotted with deep red on the outside. Plants are really floriferous.
Dendrobium gracilicaule is a reported as native to Queensland and New South Wales Australia as well as New Caledonia where it grows as an epiphtye on trees or lithophyte on rocks from sea level up to 600m altitude.
Like many of the Australian dendrobiums this species flowers from new and older pseudobulbs simultaneously and so when mature produces a fantastic show of flowers.
We grow our plant in our Cool Asia section although its native range indicates it would be happier a little warmer. We grow plants in open bark and water well in the summer but keep them much dryer in the winter.
March in the school greenhouse is always Coelogyne cristata time with several clones of this wonderful species flowering together. All photographed this week we have Coelogyne cristata ‘limoniana’ with very pale yellow on the lip, the more usual variety with golden yellow on the lip and “alba’ with pure white flowers.
As well as a range of flower colour forms, clones are also variable in leaf colour, distance between bulbs, size of flowers and texture of flowers – all good reasons to grow lots of Coelogyne cristatas.
We have seen this species in the wild in Sikkim and Darjeeling, India. It grows on trees and rocks at an altitude of around 2000m above sea level. It always grows with thick moss indicating a love for damp conditions. We keep our plants wet in the summer and damp in the winter. Its altitude gives cool winters with a minimum around 6-10 0C and so we grow the species both in our Cool Asia section (minimum 10C) and our Warm Temperate section (minimum 6C)
Coelogyne cristata flowering near Tinkitam, Sikkim – on a mossy tree trunk.
To be honest, I am fed up with seeing wrong advice for growers (even in the RHS Garden magazine this month) that plants need a dry winter rest – this information has been repeated from old books clearly written by people who have not observed plants in habitat. Wild plants do not have shrivelled pseudobulbs at the end of the ‘dry season’ because they only grow in spots where the dry season is damp, such as this mossy tree in Tinkitam. So don’t let bulbs shrivel in cultivation over the winter. Saying this, the flowers can easily be damaged by water and so we avoid spraying them with the hose and reduce watering when the flowers are out.
The species has an Award of Garden Merit from the RHS and makes a wonderful windowsill orchid (again despite what is written in the RHS Garden magazine), as these windowsill plants show.
For more tips on growing Cool Asian orchids visit our orchid culture page.
This Bulbophyllum is a true miniature and we have to remember to spot it flowering with its delightful cluster of dark red flowers produced like a tiny (1cm long) bunch of grapes.
Bulbophyllum triste is found from the Western Himalayas through to South East Asia in seasonally dry forests from 800 to 1800m that experience warm wet summers and cooler dryer winters. Like many species from this habitat the species is deciduous (as shown in our photo) with the short flower spikes emerging from the base of the leading leafless pseudobulb.
We grow the species mounted in our Warm Asia Section where it is surrounded by other species from the same habitat many of which flower at this time of year, reminding us to keep a close eye on Bublophyllum triste.
We are delighted to see Abdominea minimiflora one of our favourite mini miniatures in flower again today.
Minimiflora means ‘tiny flowered’ and this species lives up to its name. As you can see the whole plant (now quite a specimen) is 6cm across and the flowers are about 2mm across.
The flowers themselves have a ‘large bowl shaped lip and remind us a little of rows of ‘minions’ from the film ‘Despicable Me’ – what do you think?
The species is found in Thailand, Malaysia and the Philippines and grows as an epiphyte (on trees) or a lithophyte (on rocks) in hot lowland rainforest. This is habitat that we have explored extensively in Sarawak where there is a great diversity of tiny orchids that we often found low in the forest on trunks and lower branches where the shade gives protection from extreme drying by the hot sun in dry periods. There is rainfall throughout the year and so we spray this species daily but in our Warm Asia section (Min 17C) it dries out quite quickly after watering. The species is related to Vanda and so has no pseudobulbs, and uses its thick roots as water storage.
The long lasting tiny flowers are produced in succession on a pendulous spikes up to 10cm long. The plant produces lots of roots when grown mounted and we hang it high in our Warm Asia section where it gets a daily watering from the hose.
This is an unusual orchid that flowers at the end of March every year with sculpural brown and cream flowers and long terete leaves. Paraphalaenopsis is a genus just four species endemic to Borneo, and since visiting to Sarawak in 2019 we have a special interest in this beautiful species.
Paraphalaenopsis labukensis comes from near the Labuk river where it grows as an epiphyte from 500 to 1000m altitude. The Labuk river is in Sabah, the adjacent state to Sarawak in the north east of the island of Borneo and about 500 miles from our explorations in Mulu national park. We can therefore expect a habitat similar to several we visited, warm and wet throughout the year.
The species has variable flower colour from yellow to dark brown and on first flowering we are really pleased with the colour of our flowers. The flowers also have a twist on the petals and sepals – we think that is probably to help advertise the flowers in all directions. The leaves are long and thin, so far only 80cm long but apparently over 2m when the plant is fully mature. A basket is great to accommodate the pendulous habit and the plant is well suited to conditions in our Warm Asia section.
Terete leaves are often the sign of a species adapted to dry climates but observing terete leaved species in Sarawak we found that they were generally in more open forest (often due to limited soils) rather than dryer habitats. We have experimented with our paraphalaenopsis, and it actually seems to prefer good shade. It would be interesting to know if anyone has field observations of the species in habitat.
The name refers to the similarity between the flowers of these and Phalaenopsis but they are actually very distinct and a real point of interest.