We have been surprised this week by an unusually late flowering from one of our Dendrobium densiflorum plants. Plants usually flower for us between Easter and early June much as it does in its native Himalayan forests. However the flowering of Dendrobium densiflorum in the greenhouse is always a special event.
This has to be one of the most dramatic orchids we grow we have been fortunate to see it flowering its natural habitat too. In Sikkim the species grows at around 1000m where it lives as an epiphyte generally in tall semi-evergreen trees with little moss as shown below. The high end of its range overlaps the lower end of Dendrobium nobile’s range and we have seen both species flowering together during April just as they do in our greenhouse,
We grow out plants mounted with heavy watering in the summer. This is one of the plants that section hops in the greenhouse to replicate its natural habitat. In the summer it grows its new pseudobulbs rapidly and we find it a home in Warm Asia where heat and heavy watering help it to grow long bulbs. Its native Sikkim becomes quite cool at 1000m in winter and so we move it for a fairly dry rest in Coll Asia from November until March. We then move it back to warm where the change in climate usually induces rapid flower development but this year has been a little delayed possibly by the relatively cool wet summer and so flower initiation has been triggered by the more recent hot spell.
It is less than a week to go until we fly to Kuching for our first Sarawak expedition and the Mendip Lab is piled high with boxes of micropipettes, pressure cookers, vortex mixers and everything else you need to build an orchid propagation laboratory. We are pleased to hear that the Laminar Flow Cabinet has already arrived by air-freight, and work is progressing at MRSM School to prepare the laboratory space ready for our arrival.
If anyone remembers BBC’s Ground Force, with Alan Titchmarsh, Charlie Dimmock and Tommy Walsh – I feel that my team are the in-vitro gardening equivalent, ready to turn your unwanted store room into a thriving orchid lab in under a week – what great TV it would make – Watch this space to see the Kuching episode unfold.
One of the most flamboyant of our orchids is this Aerides houlettiana and our seed grown plants are now eleven years old with the largest plant having five long pendulous spikes about to burst and this smaller plant with two.
Aerides houlletiana is a medium sized species native to South East Asia where it grows in warm lowland forest up to around 1000m. We saw the species in the forests around the edge of the Bolevan Plateau in Southern Laos in open forest where it experience a warm wet summer followed by a cooler winter and a hot dry spring.
We collected seed from a plant hanging in a restaurant near Tadd Fann waterfall in 2008 and the plant shown is one of the seedlings from this batch. The startling flowers are probably butterfly pollinated and left to its own devices the plant is semi pendulous with the very pendulous flower spikes hanging below the growths to allow easy pollinator access. The flowers are fragrant as well as beautiful.
We grow the species in baskets of course bark and keep plants watered all year. We keep the plants in Warm Asia (minimum 18C)
Some of our summer flowering orchids have very short lived flowers but Dendrobium cuthbertsonii starts flowering in June or July and will still be in flower at Christmas.
This beautiful miniature species is native to New Guinea where it grows as an epiphyte or lithophyte in mossy high mountain elfin forests. We find that the secret in cultivation is to replicate this habitat and so grow plant cool, wet and windy. We also find that plants prefer to grow mounted where their roots can establish on cork bark and plants can grow into impressive specimens.
The species is bird pollinated and comes in a wide range of colours including pink, orange (below), red, yellow and white – why not grow several different clones?
As I have said, the flowers are extraordinarily long lasting and we have had flowers last nine months or more however we find that the plants benefit from the flowers being removed after a few months to allow the plant’s energy to into producing new growths. It is worth keeping an eye out for woodlice that will eat the roots or red spider on the leaves as either of these can cause a plant to go down hill and not recover.
We have two new clones that are not flowering yet but when they do flower we will post those photos too.
There is lovely feature on the orchid project in today’s Daily Telegraph Gardening Section with some lovely photos too.
Without wanting to promote the Telegraph or its values we recommend buying it today.