THE EDEN PROJECT

Peter Thoday, Director, The Eden Project, on 23 November 2001

The Eden Project will demonstrate to the general public the vital relationship between plants and humans. It was the idea of Tim Smith, the restorer of the Lost Gardens of Heligan, in Cornwall and has taken over six years to develop. The relationship will be shown by providing realistic, large areas of a wide variety of plants, both wild and cultivated, growing in five different climatic regions Dry Tropical, Humid Tropical, Sub-Tropical, Warm Temperate and Cool Temperate, in four `biospheres' and one outdoor area. The areas will represent `a corner of a corner of a field' for each cultivated crop or a patch of forest, desert or savannah for wild plants.

The site was deliberately chosen to isolate it from its surroundings so that there are no views from it of the Cornish countryside, and little chance of Cornish plants invading it. A waste pit from the China Clay workings near St Austell, which was a deep conical hole of white kaolin, was re-modelled to continuously drain it, by pumping, and to fill in the bottom 15 metres (50 ft.) to provide a base. It was then landscaped; 1.8 million tons of the waste was re-arranged. Kaolin is decomposed granite and contains all the nutrients required for plants except nitrogen, but it also lacks the kind of clay necessary in fertile soil. Suitable soil was therefore made by adding green waste and 10% clay to the sand and silt on site; 800,000 cubic metres of it! Two of the four biospheres have so far been built. They are 55 m (180ft) high so that full size trees will be able to grow in them.

Plants were then gathered from various sources world-wide, particularly South Africa, California and the Mediterranean, representing three of the five climatic types. These were grown in the nursery at Reading University, whilst the biospheres were being constructed. A subsidiary objective was to conserve endangered plants and projects are being run in co-operation with Edinburgh Botanic Gardens, for South American plants, and the Seychelles for oceanic island plants.

The response from the visitors so far has been enthusiastic; 1.6 million have visited since it opened in the Spring. The educational value for children of being able to taste sugar cane, handle cotton and see coffee beans and peanuts growing is high. The guides are expert at explaining and demonstrating the features, for example, that a field of wheat, when turned into bread, amounts to one thin slice over the surface of the field.

Discussion

Many questions were asked and answered.

• Eventually the Project would be able to grow over 90% of all the plants in the world, but, in fact, it will probably grow a chosen 3% or so of them.

• Biological control is used to deal with harmful insects using 8 or 9 predators. Pollination of plants has to be done by hand as suitable benign insects for all the various plants cannot feasibly be introduced.

• There are 250 permanent employees. 460 are employed during the summer season. It is calculated that Cornwall gets £9 for every £1 spent at the Eden Project, which amounts to £12 per head for entry and purchases.

• The best time to visit is May, June or September (when the outdoor area is at its best); not on a Wednesday, which is always the busiest day of the week; in the afternoon, since the crowds arrive early in the morning. It closes at 6 p.m.

• Compared with the Welsh National Botanic Garden, the Eden Project has different objectives; it is not interested in taxonomy or `traditional' botanic work.

• The Seychelles is a granite island, not coral, and has 74 endangered species. The Eden Project is helping them set up a similar, smaller greenhouse to maintain specimens of these and provide replacements if wild specimens are destroyed.

• Plants imported are quarantined to prevent the introduction of disease.

• The biospheres are made of a plastic that has been in use at Arnhem for 22 years and it is planned to replace them after 20 years with whatever material is then proved suitable.

• There has been no problem with the public introducing disease or contamination. Their waste is used as fuel.

Donald Lovell