Sugar cane and other tasty tips on empire building

In 1877, Sir Joseph Hooker, director of the Royal Botanic Gardens at Kew, responded testily to the suggestion that the gardens be opened to the public before one o'clock in the afternoon. He announced that Kew was "the botanical headquarters of the British Empire and its dependencies": it was never intended to be "a local or even metropolitan place of recreation". If the gardens opened before noon, Hooker added, they would be swamped by visitors "who care nothing for the instruction offered by the plants". What the nature of the "instruction" was and how Kew came to be the empire's "botanical headquarters" are the dominant themes addressed in Richard Drayton's ambitious study.

"Through the story of a garden, we may explore the history of the world." Drayton begins by discussing the place of plants and botany in Renaissance and Enlightenment Europe. While others have emphasised the relationship between botany and medicine, or between the classification of plants and notions of order, Drayton is more concerned with how the knowledge of plants and their display in botanic gardens and royal pleasure grounds attracted political patronage and articulated ideas of mastery over nature and hence over peoples and places. As Drayton reminds us, the history of Britain cannot be isolated either from its European neighbours - whose gardens were a prestigious site of self-display - or from overseas trade that brought a tide of plants and prosperity to Europe.

Following the Napoleonic wars, Kew took on a new dynamism. It became a botanical institution under public control and survived thanks to political manoeuvring and a resourceful dynasty - William Hooker, his son Joseph, and Joseph's son-in law William Thistleton-Dyer, who between them served as the gardens' directors from 1840 to 1905. Although the foundations for a mutually beneficial alliance between science and government were laid under the Hookers, it was principally under Thistleton-Dyer that Kew became a central institution of Victorian science, promoting economic botany across the empire - from cinchona (one of Kew's less successful ventures) to sugar cane, coffee and rubber. One of the attractions of Nature's Government is that by taking such a broad perspective significant continuities emerge - especially between the Banksian doctrine of "improvement" and "constructive imperialism" under Chamberlain a century later. At the same time, Drayton identifies shifts in Kew's botanical domain - as in the bureaucratisation of government and the alliance of science and state - that exemplify the changing nature of empire.

Drayton's work combines an impressive wealth of Kew-based detail with a series of empire-wide forays, but recent histories of Kew have not been lacking. The argument about science shaping imperial expansion is no longer so startling. He seeks to show the global nature of scientific knowledge, to represent empire as interchange and not mere dissemination, and to contrast grandiose imperial projects with the sordid local exploitation of peoples and environments. Yet, by employing such terms as "periphery" to describe overseas territories and by failing to elaborate in any detail on how science was practised in the many equivalents of Kew overseas, he gives little sense of how nature's government actually functioned abroad or of the contradictions that assailed its confident claims and universalising agendas. Herein lie many of the dilemmas of recent imperial history, mindful of other people and other places and yet constrained by reliance on metropolitan sources. There is a bolder book here than its sources allow. Nonetheless, it is a major contribution to the unfolding history of plant imperialism and the scientific parameters of empire.

David Arnold is professor of South Asian history, School of Oriental and African Studies, London.