The Royal Botanic Garden, Edinburgh

Tony King, Romford, Essex, U.K.
Chamaerops No.47 - published online 25-06-2003

- Left: Glasshouse range with fossil trunk visible in foreground.
- Right: Tree fern house.
Photos: Tony King

Many readers will be familiar with the Royal Botanic Garden at Kew but may be less aware of one of its 'sister' gardens located in the Scottish capital of Edinburgh.

During late 2002, work commitments occasionally required me to spend time working in this wonderful city, though opportunities to visit the garden were very limited! This was not helped by the fact that garden staff physically usher everyone from the grounds at closing time, 5.00 p.m. The restricted time meant that I was not really able to explore much of the outdoor plantings, notable for being rich in unusual plants from China.

For me, being more familiar with gardens in the warmer and drier South, it was great to see thriving examples of species that prefer the cooler and wetter environment of Scotland. These are plants that you just don't encounter when visiting gardens in the South East of England, or if you do, they are much smaller in growth than their Scottish cousins.

With so little time I concentrated my visits on the wonderful complex of greenhouses, collectively known as the 'Glasshouse Experience'. The main building range makes an imposing architectural statement as the supports that keep it aloft are held on the outside of the structure, rather like having your skeleton on view. The benefit of doing so is to allow maximum space within for growing plants, even incorporating a viewing gallery in the main 'temperate' section.

The main houses were constructed in 1965, replacing an earlier range from the 1890s, and follow the modern approach of landscaped sections devoted to differing climatic conditions from tropical through temperate to xerophytic. They serve also to connect a small number of older outlying glasshouses, which include an historic palm house, constructed in 1834. As with the outdoor plantings, I was very struck by the number of plants being grown that I had never seen before, many of them original introductions from collectors made earlier last century. Other unique features are collections of species in which the garden specialises, such as those hailing from the cooler, high altitude areas of the tropics. Prominent amongst these are epiphytic species of Rhododendron from the Far East and New Guinea and plants of the ginger family.

Rather than give a guided tour (there is much to see!), I will pick out some highlights, starting in the largest area, devoted to plants from the temperate world.

This area is fairly densely planted and again whilst some plants are familiar, many were new to me. Amongst the notable specimens are a giant Himalayan Magnolia hodgsonii bearing large leaves and planted in 1939. It must be stunning when in bloom. Another wonderful tree is hailed from a genus I had previously never encountered, Manglletia hookeri, planted in 1927 and grown from seed collected in SW China by the great plant hunter George Forrest. Also from a Forrest collection, bearing his field number 18784, is the Chinese Olive, Olea tsoongii, again from SW China. Many people familiar with the majestic Oak may be less aware that this family of trees has many species that occur at higher altitude areas of the tropics. One such species that has reached tree size proportions within this house is Quercus glauca with a wide distribution across China, Taiwan, and Japan.

Moving continents, two wonderful specimens represent the flora of New Zealand. A Kauri pine, Agathis australis, now pushes at the roof of the conservatory. Normally regarded as a slow growing species, this example was planted by the late HM Princess Margaret in 1967 when it stood 13 ft. (almost 4 m). tall. The other plant, also at roof height, is a member of the Protea family, Knightia excelsa..

A final highlight in this section is a Fuchsia arborescens, planted in 1946 and now a beautiful barked tree over 12 ft. (3.6 m) tall. It was loaded with hanging bunches of purple berries at the time of my visit.

Leaving this area via a connecting glasshouse that is home to the giant Victoria waterlily during the summer, you arrive at a very special section, the 'fernery'. Not just any fernery though, a home to the largest collection of Tree fern species I think I have ever seen! To add to the primeval atmosphere these plants create, the concrete floor carries imprints of tree fern fronds and also footprints of passing dinosaurs that may still lurk amongst the shadows!

The tree fern species you would expect to see are here, such as Dicksonia squarrosa, D. fibrosa and D. antarctica, and in some cases a number have been planted to form small groves. Other more unusual species that caught my attention included a grove of many Cyathea malzinei from Mexico, a Dicksonia lanata, and a stunning, large Cyathea brownii with a very woolly top to its trunk. Having an equally woolly trunk was a Cibotium chamissoi, a species with a more delicate appearance and a dwarfer nature than many of the giants that grow here.

Amongst the tree ferns are a mixture of equally impressive plants. Ferns such as Todea barbara from Australia and large Blechnum gibbum, themselves like miniature tree ferns. Anybody familiar with the giant tropical fern Angiopteris evecta would be interested to see its slightly smaller and more cool tolerant cousin A. lygodifolia from China and Japan.

Besides ferns, there is a large and healthy specimen of the fern-like cycad, Stangeria eriopus, and a clump of the giant horsetail from South America, Equisetum myriochaetum. Very striking are two plants of a primitive conifer from New Caledonia, Acmopyle pancheri, resembling a dawn redwood or Araucaria. They have stunning silver foliage and may even have been male and female specimens.

Being a real lover of tree ferns, this is perhaps my favourite area in which to spend some time.

Moving on again through interconnecting houses, you leave behind the coolness of the fernery on a walk via hot, humid sections full of cycads, palms, orchids and other tropical species. A curiosity here is the climbing plant Dioscorea bulbifera. A member of the yam family, this one produces tubers along its climbing growths and not surprisingly is known as the 'air potato'!

Arriving in the old palm house you are again back in a more temperate atmosphere. Here, again, are large, historic plantings, many of which you will not see in many other gardens.

A famous inhabitant is the more familiar palm Sabal bermudana, though the specimen here is over 200 years old! Other giants are the bamboo, Bambusa vulgaris, from India with its thick culms, and a Livistona australis almost 20 ft. (6 m) tall.

Very impressive was the tallest Hedyscepe canterburyana I have ever seen, over 16 ft. (4.8 m) high and carrying some ripening fruit. This is a favourite palm of mine and one of a small number of species that I found grows well inside the home.

Amongst the rarities are three 'primitive' members of the conifer family, Araucaria hunsteinii from New Guinea (planted 1962), Podocarpus milanjianus from temperate East Africa, and Taiwania cryptomenioides. An attractive evergreen tree from the cooler high altitude regions of Thailand, Gordonia dalgleishiana, also 'stood out' amongst the plantings.

At the opposite end of the 'complex' is another house worthy of mention, devoted to the collection of plants that occur at high altitudes in the tropics. It is cool, airy and humid, with logs dripping with mosses and epiphytes, many of which are species of Vireya Rhododendrons, such as R. stenophyllum from the island of Sarawak. It carried large, waxy orange flowers on a small bush of narrow leaves, each edged in dark red-stunning!

Magnificent too is a climber from New Guinea, Tecomanthe volubilis, with divided leaves and masses of large, pink, bell-shaped flowers, pure white inside.

More sinister is the large collection of insect eating plants that are also grown here. Amongst these is a huge clump of the 'sun pitcher', Heliamphora nutans from the summit of the Tepuis of Venezuela, a plant adapted to a specialised habitat that is very difficult to cultivate. Many of you will be familiar with the heat loving genus of 'pitcher' plants, Nepenthes, but may not be aware of the cooler growing species from locations such as the slopes of Mount Kinabalou on Borneo. Three such species are represented, N. fusca, N. sanderiana, and N. rajah that carries giant pitchers at ground level.

The outside area surrounding the glasshouses is also richly planted with a wide selection of semi-tender bulb, perennial and shrub species. Most notable were several large clumps of Fascicularia bicolor, almost all resplendent with their scarlet, 'autumn leaf' colour. A fine clump, almost 5 ft. (1.5 m) tall, of the species 'busy lizzy', Impatiens tinctoria from the volcanic slopes of central Africa, was full of its substantial blooms. Resembling large white butterflies floating over the foliage, the flowers make this species nothing like its relatives used in summer bedding schemes. A large Lapageria is trained up a shady wall and was heavy with the large, waxy, bell-shaped blooms that make it such a prized feature of any garden that it finds to its liking. It is not always easy to please. Not doing so well was a modest Chamaerops; perhaps the cooler climate isn't quite to its liking?

Between the 'old palm house' and northernmost section of the main glasshouse range is an area where Trachycarpus and primitive conifers such as Araucaria, Ginkgo and Metasequoia flourish, no doubt appreciating the higher rainfall. It is here that one of the 'oldest' plants in the garden can be found. This 10.5 m (35 ft.) long fossilised trunk of a pitys tree was excavated from a local quarry, having grown in this area 320 million years ago.

This is certainly a garden to which I would like to return with enough time to really explore and appreciate the wonderful range of unique plants that are grown there.