Obituary : Sir Geoffrey Jellicoe

Sir Geoffrey Jellicoe was one of the century's greatest landscape architects. His contribution to landscape design - a discipline he credited above building design as the "Mother of all Arts" - has been described as equal to that of one of his great heroes, the 18th-century gardener Capability Brown.

Among Jellicoe's triumphs are the grounds of Royal Lodge at Windsor, Sandringham in Norfolk, Sutton Place near Guildford, public gardens at Hemel Hempstead and the Kennedy Memorial at Runnymede, together with many small private commissions. But exceeding them all in scale and complexity was his work on the Moody Historical Gardens in Galveston, Texas, which he started in 1985. It is a project due to commence on site in the next few years and which Jellicoe suspected he would never see completed. Yet, so powerful was his vision for the gardens that he felt no sadness at the prospect of not seeing their realisation - "In my mind I know the gardens, I've already walked through every inch of them."

The designs for the Moody Gardens provided a fitting tribute to, and culmination of, Jellicoe's 70-year-long career. They were conceived as a three-dimensional history of man starting with the Garden of Eden. When complete, they will embody his thoughts and ideas about landscape as a reflection of the civilisations which created them.

However, Jellicoe did not set out to be a landscape designer and, surprisingly, confessed to a hatred of gardening.

He was born in 1900, educated at Cheltenham College and then trained to be an architect at the Architectural Association. It was while at the AA that his interest in landscape was first kindled when he and a fellow AA student, J.C. Shepherd, toured Italy to study the country's famous gardens.

The trip had been made at the suggestion of a lecturer who told the students that nothing had been written on the subject of Italian gardens since the early 19th century and that the time was well overdue for a new appraisal. The result of the tour was Jellicoe's first book, co-written with Shepherd, entitled The Italian Gardens of the Renaissance. It was published in 1925, is now in its fifth edition, and is regarded as a standard.

On his return to England, Jellicoe chose not to pursue a career in landscape design, but instead set up an architectural practice. He did, however, in 1929, help found the Institute of Landscape Architects and then went on to set up the International Federation of Landscape Architects, of which he was an Honorary Life President.

Among his early pre-war work Jellicoe designed the crisp modernist Caveman restaurant at Cheddar Gorge in Somerset and the Gordon Russell showrooms and factory in London. Shortly after the Second World War Jellicoe spent several years in Zambia working on schools, hospitals, airports and hotels and then in the Caribbean where he designed a Palladian-style, coral-built mansion in Barbados.

His post-war work in Britain included the Civic Centre and other municipal buildings in Plymouth, public housing and industrial buildings, a department store in Guildford and swimming baths in Cheltenham. He also qualified as a town planner and prepared plans for Guildford, Wellington and the centre of Gloucester, but most important was his Master Plan for Hemel Hempstead. Although not all his ideas were executed, he did see the inclusion of his public gardens with their long, serpentine lake, which has remained a hugely popular oasis.

Throughout his career, Jellicoe was frequently asked to advise on gardens and landscaping. During the war he became one of the first landscape architects consulted by industry. His designs, drawn up in 1942, for the Earle's Cement Works in Derbyshire set an example for others to follow. It was here that he demonstrated how a business with the potential to scar the landscape could be incorporated into rural areas and, indeed, create the opportunity for attractive, new landscape. But despite growing demand for his landscape design he resisted making it his full-time work because he feared it would not be financially viable.

However, with each new landscape commission Jellicoe became increasingly convinced that garden design was more complex and affecting than was generally accepted.

He had first noticed the impact landscape could make when visiting the Italian gardens - they appealed not just to his aesthetic sense but also to his spirit. He accepted that beauty was a potent force on its own, but felt that designers could add an extra dimension to reflect the personality of the area and local people, or a garden and its owners, and somehow "plant" elements which were almost mystical. It was a difficult concept to explain but his theory was tested at Hemel Hempstead.

"Some years after the gardens there were complete I was contacted by the parks department saying they had wanted to change the shape of the lake and reclaim part of the gardens for a new fire station," Jellicoe told me. "It was extremely unusual for them to bother to contact me - I had left the project years before. But the council official explained that he and others in his department felt curiously uneasy about making the alterations and wanted to talk to me about them. The truth was that, unbeknown to them, I had designed the lake as a serpent which it was really only possible to see from the air. They wanted to chop a bit off the head and instinctively felt it to be wrong." Jellicoe explained his reservations and the building work was cancelled.

Shortly after this he discovered the writings of Jung and immediately many of his ideas were pulled into sharp focus. Of particular interest were Jung's thoughts on the workings of the conscious and subconscious - the material and the spiritual.

One of the clearest interpretations of Jung's ideas was at the Kennedy Memorial. Completed in 1965, the site close to the Thames river in Surrey was designed by Jellicoe as a place of pilgrimage and contemplation where visitors wove their way through a wooded hillside on a path made of thousands of stone setts, each representing a pilgrim, to emerge at a light-filled clearing and the simple, carved memorial stone. Nearby was seating - two raised benches representing Kennedy and his wife and smaller stones symbolising their children. The combination of symbols, hard and soft elements, light and shade, and the climb to a hilltop give the place an aura and great sense of dignity.

Throughout the 1960s and 1970s Jellicoe published several important books including the three-volume series Studies in Landscape Design. But among the most revered was The Landscape of Man, published in 1975, which was co-written with his wife, Susan. (Susan died in 1986.) Here Jellicoe expounded his ideas on the importance of landscape and its ability to reflect the civilisations which occupy it. It was this book which inspired the Moody Historical Gardens project.

The book appeared during Jellicoe's retirement from professional practice. He used his seventies to rest and travel, and in 1979 was knighted for his services to landscape design. The knighthood, however, sparked off a new phase in his career and resulted in a decade of prodigious output.

Aged 80 he was coaxed from retirement by his old friend Sir Hugh Casson to design gardens for Sutton Place, near Guildford. Such was their success that a flood of commissions arrived from around the world - public landscaping in Italy, private commissions in Britain and the Moody Gardens in America.

Jellicoe described the Moody Gardens as "the summary of my life's work". The 25 acres of gardens form a part of a massive 20-year scheme to revitalise 150 acres of sea marshes off the Texas coast near Houston. The $50m gardens project is intended to be both commercial and educational - the plants and architecture will be as historically accurate as possible.

Visitors will pass through the scenery by boat or on foot from the Garden of Eden with its enormous moss-covered apple and mysterious serpent, past an Egyptian garden, then a Roman one and so on through almost 5,000 years of history taking in 15 cultures from East and West. There will be neat, formal gardens, rolling romantic landscape, waterfalls, caves and monsters.

Following his first tour of the site Jellicoe produced, over-night, his original sketch for the gardens. This was then developed into a series of enormous, and beautiful drawings. Jellicoe had developed a distinctive style of design which was illustrative and colourful and was made on enormous sheets of paper the size of hearth-rugs.

Work on the Moody Gardens project was carried out in a small office at his home on a top floor in Highpoint. Until last year he eschewed any temptation to retire to the country and adored living in his modern apartment with its views out over the gardens, parks, schools and houses of Hampstead and Highgate. The choice of address, his taste for 20th- century art and his interests in Jung and the green movement were all indications of Geoffrey Jellicoe's progressive thinking. He always enjoyed exchanging ideas with young people and regularly gave lectures to students where his favourite opening line was: "If people try to tell you life begins at 40 don't believe them - it begins at 80."

Geoffrey Alan Jellicoe, architect and landscape designer: born London 8 October 1900; Principal, Architectural Association Schools 1939-41; President, Institute of Landscape Architects 1939-49; CBE 1961; Kt 1979; RA 1991; married 1936 Ursula Pares (died 1986); died Seaton, Devon 17 July 1996.