Tying orchids onto bark
The team leader of Kew's Orchid Unit shows how we look after these fantastic epiphytes and divulges the secret of nylon tights in helping some orchids grow.
This week we are in the Orchid Unit, managed by Christopher Ryan.
One of the tasks that regularly needs attention is the mounting of epiphytic orchids onto pieces of Cork Oak (Quercus suber) bark. Cork Oak provides a renewable source of bark. Kew has been growing orchids since its inception, and has one of the most comprehensive tropical collections in the world. We grow orchids that live in all sorts of habitats, from those living in rocky crevasses in southern Madagascar to species living in wet soil next to tropical rivers in Ecuador; even very rare orchids that are found in the meadows of England. However, the majority of the collections cared for by Christopher’s team are epiphytic species. An epiphyte is a plant that grows on a tree but does not tap into the tree for nutrients; it simply lives on its surface.
When I caught up with Christopher he was showing an intern the ins and outs of mounting a Bulbophyllum onto bark.
Christoper shows an intern how to mount a Bulbophyllum onto bark
“First you have to select a good piece of bark. Make sure it’s big enough for the orchid you are mounting to establish and grow on. Once you are satisfied, offer the plant up to the bark, find the right area to put it on, line the plant up with the raised parts of the bark for firm attachment, and tie the orchid tight onto the bark, the roots will naturally find their way into the fissures. We used to line the fissures with moss but recently we’ve found that the orchid does not need this to establish.”
We use ladies tights to tie the specimens on. It may sound strange to some, but it really works. Nylon tights (cut into strips and tied together to make strings) will stretch and give, so that new growth is not damaged as the plants grow and establish. When we first started using tights, we had a problem getting enough of them. Regular requests went out to the entire garden for staff and volunteers to send in their old, used (and washed!) tights for the orchids, but we still didn’t have enough... Fortunately, a well known nylon stockings company heard of our plight and now regularly sends boxes of its factory rejected tights.
The previous Orchid Unit manager, Kath Smith, is now the coordinator of the scientific living collections at Kew and she taught us all the very specific way that the orchids had to be tied. She once said to me, “take the time to make sure that you get it right first time. That bark will be their home for the rest of their lives.”
Bulbophyllum growing on bark
Similarly, Christopher has carried on Kew’s tradition for excellent horticulture, “The plant should be tied so that it doesn’t move and the upper leaf surfaces need to face upwards. The result should be tidy and well presented in the same manner that it would look in the wild. The label should be tied on the bottom right corner, with enough play so that it can be read from any angle. The hook for hanging the entire bark should be at the top in the centre and created in such a way to make it easy to take off and on the metal grills we hang them on.”
Christopher in the Tropical Nursey
Considering that the oldest accession of Bulbophyllum growing in the nursery came to Kew in 1903, this little specimen could go on to do great things. We use the orchid collections mainly as a kind of living reference library for scientists to study, and also as a great display tool. Most of the special individuals in the glass cases found in the Princess of Wales Conservatory come from Christopher and his small team of horticulturists.
- Nick Johnson -