Moore, Sir Frederick William (1857–1949), horticulturist and rugby player, was born 3 September 1857 in Dublin, second eldest of three sons and two daughters of David Moore (qv), curator of the Botanic Gardens, Glasnevin, Dublin, and his third wife, Margaret (née Baker), of a Dublin building family. He was brought up in the Botanic Gardens and showed an early interest in plants and natural history. He received his early education in Dublin, but in 1869 was sent to school in Hanover with his brother David. He returned to the Royal College of Science in 1872. Afterwards he passed the examination for the Indian Forest Service but was not selected for training. In 1875 he was sent as an apprentice to a nursery in Ghent, Belgium, moving on to the botanical garden of the University of Leiden in 1876. In his spare time he rowed with the university rowing club, later becoming an honorary member. During his time on the Continent he acquired fluency in German, French, Flemish, and Dutch, which were useful in his later botanical travels.
In 1877 he returned to Ireland as head gardener of Trinity College Botanic Garden, where his father and uncle Charles Moore (qv) had received their training and his father had been foreman (1828–34). He improved the walled gardens and took a special interest in herbaceous plants, exchanging many species with Glasnevin. After the death of his father (June 1879), he canvassed for the curatorship of Glasnevin. The post was not advertised and he was appointed in September 1879, at the age of 22.
He worked with enthusiasm and initiated many developments and improvements in Glasnevin, including extending the size of the gardens as well as the arboretum, establishing a new rock garden, and constructing new weirs. New glasshouses were built, including the great palm house. He maintained the important collection of carnivorous plants started by his father, and (like him) was interested in establishing difficult and tender plants in sheltered Irish gardens. He travelled abroad regularly, collecting plants and seeds and building up valuable contacts.
In 1880 the Department of Science and Art appointed as scientific superintendent to the gardens Prof. William McNab (qv), who, it was rumoured, had wished to become director on the retirement of David Moore. After the death of McNab this position was abolished in 1890 and the Department of Science and Art upgraded Moore's title from curator to keeper. He was then responsible for all horticultural matters in the gardens. His reputation as a horticulturist and gardener grew, but he showed little interest in fieldwork or pure botany. His overriding passion was for orchids. Thus the emphasis of the gardens changed and there was little work done on native plants. However, during his time the collection grew enormously and he actively encouraged exchange of plants. The gardens gained an international reputation for being both interesting and beautiful. As well as his interest in horticulture, he continued the apprenticeship courses for young gardeners. He became a lecturer to the Albert National Agricultural Training Institute, Glasnevin, in 1894 and, unusually for the time, started a training course for women in 1898.
In 1901 the control of the Royal Botanic Gardens was transferred from the Department of Science and Art to the Department of Agriculture and Technical Instruction. Moore then undertook a scheme to encourage fruit-growing by small farmers. Unlike his father he wrote only a few papers and articles. However, he was associated with the development of many Irish gardens including Mount Usher, Kilmacurragh, and Headfort. He led an active life and served as honorary secretary to the Royal Horticultural Society of Ireland and the Royal Zoological Society of Ireland. He received many horticultural distinctions and honours: the Victoria Medal of Honour (1897) from the Royal Horticultural Society of London; honorary degrees from the Royal University of Ireland (1908) and the University of Dublin (1939); and a knighthood (1911) from King George V on his visit to Ireland. On a personal level Moore was known as a lovable character who was in his true element in the garden.
He was also a noted rugby player and was capped four times, playing as a forward in internationals against Wales (1884), England (1885), and Scotland (1885–6). Two of his brothers also played for Ireland in forward positions: D. Frank Moore, capped four times (1883–4), played against England, Scotland, and Wales, and C. Malcolm Moore, capped three times (1887–8), played against Scotland and on the team that defeated Wales for the first time (1888), and also refereed two international matches (1886). Frederick played for the Wanderers club and was the first of their members to become president of the IRFU (1889–90). During a time of disputes on regulations between the four unions (Ireland, England, Scotland, and Wales) he proposed the setting up of an international board, which came into place after a meeting in 1886, and became the ruling authority on the game. He was seen as one of the great Irish rugby legislators and was influential in setting up a special committee for international team selection.
On his retirement in 1922 he moved to Willbrook House in Rathfarnham, Dublin, with his wife Phylis (daughter of Robert Paul, JP, of Dublin), whom he had married 19 November 1901. There they created a new garden. She was a noted horticulturist and helped in founding the American Rock Garden Society (1935). She was also president of the Royal Horticultural Society of Ireland (1950–52). He died aged 92 on 23 August 1949 and was buried at Whitechurch Parish graveyard, Rathfarnham, Dublin. He and his father together had worked in the Botanic Gardens for a total of eighty-four years, raising its profile to a world-class standard. He had one son, Frederick David Moore (1902–97), who became a major-general in the British army.