Thursday, 14 February 2013

Orchid Festival

The Princess of Wales Conservatory is another of Kew’s grand glasshouses, with the primary attraction here being the assortment of controlled climate zones offering a mixed bag of flora. One minute you can be perambulating languidly amongst a chilly desert landscape, marvelling at the spiny cacti, and then the next find yourself on the periphery of a tropical pond, enjoying Amazonian waterlilies! Every year this fascinating display is enhanced by a late-winter festival, with tropics mayhem and a celebration of colour at the time of year when perhaps we need it most of all. The Orchid Festival started last weekend, and an unseasonal explosion of colour has lifted the old spirits and left us all yearning for the coming spring! This floriferous glory continues until Sunday 3rd March, and more information can be found here.
The following images were taken on my field telephone device, after the usual photographic contraption recently bid me adieu. Blasted thing! Normal service will resume shortly.

A riot of hanging baskets and container displays set the scene, with hybrid Phalaenopsis orchids taking centre stage

Vast pillars have been decked out in the Phalaenopsis hybrids

This delightful medley is amongst the best of the pillars, with yellow Oncidium orchids providing a pleasing contrast of form

Bromeliads provide an excellent counterpoint to the Orchidaceae experience, with the blue and red inflorescence of Vriesea splendens being particularly unusual!

This clustered beast is the King Orchid, Dendrobium speciosum

A species orchid display is permanently housed in the POWC orchid zone that changes almost every week, and features such delights as this beautiful slipper orchid

And also this hybrid Brassocattleya!

The cacti zone is a wonderful place to explore, and surprisingly colourful at this time of year!

The yellow spikes of Aloe africana combine well with the daisy-heads of Senecio medley-woodii

This Echinopsis has an incredible form, and huge white blooms unfortunately not on display yet

“You there, boy! What day is this?”, Lord Turtle simply hasn’t the time for any of my nonsense today! Several tanks house this haughty egg and some other aquatic chaps

Water dragons can regularly be seen here, parading themselves about the place and providing some element of pest control. Akin to old Buster at Hidcote, they will stretch themselves out on the path and refuse to move regardless of how near you get! We have two large specimens over in the Palm House but they are considerably less gregarious, living mostly in the grates below the paths and so making any photography attempts futile

Thursday, 7 February 2013


Occasionally when a plant species is difficult to propagate with traditional methods or in danger of extinction, and in many cases very often both, we must place our faith in science and the lab-coated coves initiated in such sorcery! Micropropagation is the growing of plants from seed or tiny pieces of plant tissue in sterile, laboratory conditions, and is utilised to cultivate those dreadful nuisances that are indifferent to a tray of John Innes and a bit of bottom heat. Kew’s Micropropagation Unit was set up in 1974 and produces thousands of plants each year to repopulate endangered species in a series of labs dedicated to this cultivation.
Orchids are one of the success stories at Kew, with this plant family in particular need of specialist techniques. Although they often produce thousands of seeds orchids rely upon fungi in the soil for germination, as theses dust-like seeds lack an endosperm, the part of a seed where a small food store powers the initial stages of germination, before the first leaves are unfurled and photosynthesis becomes the main engine for plant growth. The soil fungi form a symbiotic relationship with the tiny seed, laying on the food that enables germination! This happy matrimony is undoubtedly heart-warming, but from a propagation perspective is insanely difficult to recreate in the potting shed, needing the usual temperature and moisture requirements plus that blasted fungi. As usual science holds the key with micropropagation enabling germination without fungus, in a process called asymbiotic germination that provides all of the nutrients that the fungus would normally supply. This propagation usually does not involve soil, but instead various cocktails of sugars, minerals and vitamins solidified in agar jelly, which holds the concoction together and gives the plants something to root into. The development and success of these techniques has resulted in the saving of species such as the beautiful Lady’s Slipper Orchid, Cypripedium calceolus, which had been reduced to one single specimen left in the wild but was repopulated and reintroduced in a collaboration between Kew and English Nature!
Cryopreservation is used to store plant tissue and seeds, freezing material at -196°C
(-320°F) in these sealed tanks with liquid nitrogen!

Tiny orchid seed is smeared on to the agar jelly mixture

Sincere apologies for the quality of this image, but looking down the lens of a microscope we can see thin grains of orchid seed and the round, swelling seed that has already began to germinate

Eventually roots and shoots develop from the germinated seed

Seedlings are ‘potted on’ to glass jars, where they continue to develop before eventually being finally transferred to traditional soil potting mixtures and then reintroduced to the wild!

Micropropagation does not just involve seeds; here new shoots are developing on a miniature cutting

Some species are not terribly fond on the agar jelly cocktails, so a rough plug mixture is used instead

Even succulents can be raised with this method!

Carnivorous plants, Dionaea muscipula, can be seen here. As the nutrients in the agar mixture are used up, yellowing leaves on the plants indicate the time to pot on to a soil based medium

It’s propagation, but not as we know it!
A little off the beaten track, but I hope this offers an insight into some of the madness going on here at Kew! As an aside the good eggs over at Tweed Pig have kindly featured me in their ‘pin-up’ series, please click here to take a look.