Tropical Nursery blog

This Sunday, the 19th September, Kew’s Tropical Nursery cordially invites members of the public to go behind the scenes and learn about the fascinating work that goes on here.

Behind the scenes in Kew's Tropical Nursery

This will be another rare chance to see the smallest water lily in the world at Kew; Nymphaea thermarum. With leaf pads 1cm in diameter, this “thermal” water lily grew besides freshwater hot springs in southwest Rwanda. It disappeared from there about two years ago due to over-exploitation of the hot springs, damaging this fragile habitat. Fortunately, horticulturist Carlos Magdalena at the Tropical Nursery has solved how to propagate them regularly and in large quantities; helping to safeguard this species for the future.

Nymphaea thermarum growing at Kew Gardens

At the Open Day there will also be information on propagation techniques, conservation work and pest control, as well as displays of the amazing tropical plants raised in the nursery, including Orchids, Carnivorous plants, Bromeliads & Cacti. There will also be a chance to see rare and endangered plants, including species from the UK Overseas Territories. This is a great opportunity to learn about the role that the Tropical Nursery plays in supporting the scientific, display and conservation work that goes on at Kew. Nursery staff and volunteer guides will be on hand to talk about the plants on display and to answer any questions.

The Tropical Nursery Open Day will be between 11:00 until 17:00 (last entry at 16:00). Please enter through the gate beside the White Peaks café.

We hope to see you there. In the meantime, I shall get back to cleaning my window panes.

- Sam Crosfield -

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 -

Welcome to Kew’s Tropical Nursery blog. 

My name is Nick Johnson and I manage one of the four teams that work in this huge nursery, which has the largest roof span in Kew. With the help of my colleague, Sam Crosfield, we will regularly be bringing you accounts of interesting things happening here.

The Tropical Nursery from above

Whether it’s the Waterlily House propagation drive, repotting cacti, how we look after the orchid collection  or simply an interesting plant of the week by one of our students, come to this page to see what we’re up to.

Introducing the Tropical Nursery & Jodrell Glass

The Tropical Nursery, rebuilt in 1998, is one of two tender plant raising and reserve facilities for the Great Glasshouses and Training Section. Jodrell Glasshouse is a support facility primarily raising plants use for scientifc research by Jodrell laboratory. The nurseries provide facilities for the propagation, establishment and growing on of plants from various habitats encountered within the tropical/subtropical regions. There are over 45,000 plants held in the nursery at any one time! These plants are grown to support the public conservatories for educational and display purposes and may by used for scientific purposes by  scientists from around the world. The nursery also houses many of Kew's conservation plants, mainly from island habitats. 

The nursery covers an area of 6500 m² and is divided into 21 climatic environments which are separately controlled and monitored by a computer. These zones are distributed managed by four teams – Dry Tropics, Moist Tropics, Orchids and Temperate/Conservation Collections.

Eleven permanent staff work in the Tropical Nursery, supported by up to ten students, apprentices and trainees and 28 horticultural volunteers. Daily maintenance of the collections involves watering, feeding, repotting plants, propagating and monitoring plant health throughout the year.

Sam Crosfield, left, and Nick Johnson, right, in the Tropical Nursery

Introducing Nick Johnson

Nick is the team leader of the Temperate and Conservation collections. Nick has been at Kew for nearly ten years and has worked in the Tropical Nursery for eight of them. Nick manages a small team that cares for the temperate collections and the increasingly important threatened island flora collections. Nick provides propagation training to the students in the Nursery and has had the good fortune to have travelled to some amazing island habitats, including Madagascar and St Helena to assist conservationists in their bid to save endangered plant species. 

Introducing Sam Crosfield

Sam is the second in command of the Dry Tropics collections. Sam came to Kew in 2006 as a diploma student and, after finishing the three-year course (which included a travel scholarship to study the flora of Mauritius), Sam took a permanent position in the Nursery. Sam currently looks after the warm arid zone which includes the amazing collections of Melocacti, Euphorbias and arid  Madagascan flora.

- Sam & Nick -