Dendrobium delacourii
I inherited this plant from the collection of the late Alan Booth after he died, very prematurely, in 1993. Alan was an enthusiastic and knowledgeable grower and exhibitor, and a keen supporter of the Society for many years. Den delacourii is an unusual Dendrobium, not often offered for sale in this country and this particular plant doesn’t quite fit the description of the species given in Baker and Baker’s monograph on the genus. It is an intermediate-growing species, widespread in south-east Asia, and very closely related to Den venustum. It is quite distinct from it though – D delacourii flowers in May on short (c.5cm) compact pseudobulbs, with fewer, larger flowers whereas Den venustum flowers in September on longer (c.15cm) thinner, pseudobulbs. Den ciliatum is probably a synonym of D venustum differing only, it seems, in the length of the cilia on the lip of the flower. This plant is deciduous: the leaves fall in late autumn and then it is kept almost dry until the new growths appear in spring. Careful watering is started now but when growth is well-established it is watered every day. I feed only once or twice with Orchid Grow before the flower spikes show in mid-April, when I change to Orchid Bloom, then back to Orchid Grow, tailing-off in autumn when the leaves start to go yellow. It is kept hanging up on a piece of cork bark, in good light near the greenhouse door (not on the back of the door – to save anyone asking). The drop in temperature from a minimum of 70F in the daytime to a minimum of 60F at night that my thermostat provides, is apparently important in inducing flowering. Ted Croot
Dendrobium New Star
This one is a plant that I have been growing on now for 10 years, dropping on as each pot has become full. I keep it in reasonably good light all year, with moderate shading in the summer, and with a little during the winter.
Temperatures in that part of my Conservatory regularly reach 28-30C and go down to 12C on winter nights. This seems to be a temperature tolerant hybrid, based to a large extent on D. nobile but containing contributions from six other species (notably D. regium) via some complex breeding. It does not take well to high light, preferring some shade. During growth, which will begin during flowering, feed and water it copiously, but when terminal leaves are spotted on the canes, allow drying off until you can see that the new buds forming along the pseudobulbs are really flowers or all you will get are kiekis!
The growing medium is a mix of medium bark and coco husk with a little charcoal thrown in for seasoning. The centre of the plant has been in the same growing medium now for 10 years but the bark seems to stand up well with little sign of deterioration and the plant does not seem to mind. Charles Ford
Dendrobium unicum
This species of Dendrobium can be found in Northern Thailand, Laos and Vietnam growing at altitudes of 800m to 1500m on low shrubs and rocks, with seasonal rainfall and strong light. The flowering season in the natural habitat is winter into spring, but in my greenhouse it has flowered from late June to mid August. I purchased mine at The Britannia Hotel, Bramhope, in February 2014, courtesy of Phoenix Orchids. Grown on a slab of cork on the cooler side of intermediate, it is protected from the sun on the south side of the greenhouse and gets the full northern light on the north side. My growing temperature ranges between 9 – 12 degrees centigrade on the cooler side to 20 – 26 degrees centigrade on the warmer side and occasionally 30 degrees centigrade when I am not looking! Because the plant is grown on a slab of cork it requires regular watering but occasionally in cooler weather the plant is allowed to dry out, but not for long. I only feed intermittently. Through trial and error I have found that keeping the greenhouse floor damp increases the humidity and compensates if the temperature gets too high. J.A. Charlesworth
Dendrobium oligophylum
(Syn. Den tixieri) This plant was a piece of a much larger plant growing at Papa Rohl’s nursery in Paradies, near Souest, in centralGermany. We were on a visit in 2005 with Nev and Ruth Brown who knew the Rohls well and had been there several times before.
In the wild it grows in mainland Thailand (not, apparently, in peninsular Thailand), Cambodia and Vietnam where it flowers through most of the year. It occurs at altitudes of between 2000 and 2500 feet and where there is good light. Summers are wet with temperatures between 20C at night and 30C by day so it’s really a warm-growing orchid. “Winters” are drier and while the temperature may drop to about 15C at night it rarely falls below 30C by day.
In my greenhouse it does get good light but the thermostat is set at 16C at night (it drops lower when there’s a power cut!) and 24C by day – only on a sunny day might it shoot up to 30C. It’s not exactly ideal but it survives and flowers pretty well. It only flowers in the autumn though but the flowers are long-lasting and it’s usually in bloom for several weeks. Clearly it is a very tolerant and adaptable species! Ted Croot
Dendrobium venustum
I bought this plant from Willi Kenntner’s nursery during our expedition to the D.O.G. Congress at Ulm in Germany in March 1999. It is an unusual Dendrobium, not often offered for sale in this country and this particular plant doesn’t quite fit the description of the species given in Baker and Baker’s monograph on the genus. Recently it seems, it has been separated into two species: Den venustum which flowers from the apex of the cane and Den simondii which flowers from the lateral leaf axils. This plant appears to fit the latter description.
It is an intermediate-growing species from what used to be known as Indo-China (Thailand, Burma, Vietnam, Laos, Cambodia) and it is also very closely related to Den delacourii. It is quite distinct from it though – D delacourii flowers in May on short (c.5cm) compact pseudobulbs, with fewer, larger flowers (mine is usually on our stand at Chatsworth) whereas this one flowers in September on longer (c.15cm) thinner, pseudobulbs. Den ciliatum is probably a synonym of one or the other species, differing only it seems, in the length of the cilia on the lip of the flower. It’s quite a complicated set of very similar species.
This plant is deciduous: the leaves fall in late autumn and then it is kept almost dry until the new growths appear in spring. Careful watering is started now (the new roots are easily drowned by standing water). When growth is well-established it is watered more freely provided that drainage is good. I feed with Akerne’s Rain Mix, gently increasing the feed in spring and tailing-off in autumn.
The compost I use is a very little chopped sphagnum moss with medium bark, charcoal and coarse Perlite – drainage must be good. It is kept hanging up, in good light and in continuous breeze from a fan. The drop in temperature from a minimum of 70F in the daytime to a minimum of 60F at night that my thermostat provides, is apparently important in inducing flowering. My plants always get this, so I can’t say what happens if they don’t. Ted Croot
Dendrobium aemulum –
The Iron Bark Orchid
A species that grows on Iron Bark and Brush Box trees favouring the Grey Ironbark (Eucalyptus paniculata) and to a lesser extent the Broad Leaved Ironbark (Eucalyptus fibrosa).
This is one of a few orchids that grow high up on Eucalyptus trees; this is due to most Eucalyptus trees habit of shedding bark. The Iron Bark, which does not shed, has solid, spongy and very rough bark which allows the roots of the plant to penetrate deep into the bark hollows. It’s range is from the south coast of N.S.W. to S.E. Queensland and it is a plant of the open dry sclerophyll forest where it will withstand extremes of temperature ranging from 40 degrees down to -5 Celsius.
I grow this plant mounted on a Cyathea Tree Fern slab in reasonably high light conditions. It is trickle watered once a day in summer and around once a week in winter when the plant is resting. Fertiliser is always applied and moderated by the watering regime. Temperatures range from 30c to 14c at night. Charles Ford
DENDROBIUM PHALAENOPSIS
I have had this plant for about 18 months. It was labelled Emma White but the flowers are a lovely shade of pale green with pink veining on the lip. As well as the two spikes in flower now, it has one old flowered one and six new growths, so it will need re-potting soon. It is potted in medium bark with a small amount of peat and sponge rock. All my orchids grow in the south-west-facing conservatory with intermediate to warm temperature. I water approximately weekly weakly with Miracle Grow all purpose liquid plant food and flush with plain water once a month. I have also started using Humate monthly. Valerie Minogue