BBC Radio 4 – Squirrels & Knotweed

Last week I was delighted to share some of my knowledge of exotic and invasive species on national radio, thanks to an invitation by Kat (@harpistkat) and Helen Arney (@helenarney) to appear on their series “Did the Victorians Ruin the World?”

In the episode I talk about the introduction of the grey squirrel to Victorian Britain and how negative attitudes towards native red squirrels rapidly changed thanks to the new arrivals. I also discuss the introduction of Japanese knotweed, which was once advertised as an ornamental and desirable addition to every garden.

You can listen to the episode at:



Book Review: The British Arboretum: Trees, Science and Culture in the Nineteenth Century

Today, the arboretum – a green space containing systematically planted trees – may seem a commonplace and enduring aspect of the British landscape. Yet The British Arboretum (2011) demonstrates that, in the nineteenth century, arboretums were sites of scientific innovation, public education and Edenic ideals. Authors Paul A. Elliot, Charles Watkins and Stephen Daniels move from the late-seventeenth century and depleted British woodlands to arboretums as public recreation grounds two centuries later. Standing over this cultural and scientific history is the figure of John Claudius Loudon, author of the Arboretum Britannicum (1838), an influential study of hardy British trees and shrubs.


Plates from John Claudius Loudon’s Arboretum Britannicum (1838).

In addition to shaping scientific and cultural landscapes, arboriculture altered the biotic makeup of the British Isles. From the seventeenth century, growing numbers of exotic trees were imported to adorn and enrich gardens, parks and plantations. Arboretums were established to classify and label growing numbers of new arrivals. In the mid-nineteenth century, the Japanese larch (Larix kaempferi) became so popular that it was imagined the tree would replace its European cousin. The scientific name of the species honoured German physician and naturalist Engelbert Kaempfer, who introduced numerous Japanese plants to Europe in the eighteenth century, including the troublesome Japanese knotweed (Fallopia japonica). Imported varieties required specialist knowledge, as existing taxonomy was unable to cope. The Linnaean system was of limited use, British botanists subsequently adopting the “natural system,” which combined systematics with plant physiology and anatomy.


Plan of the Nottingham Arboretum:

In its second half, The British Arboretum provides readers with a series of case studies of historical arboretums. One of the first purpose-built Victorian public parks was the Derby Arboretum, designed by Loudon on behalf of industrialist Joseph Strutt in the early decades of the nineteenth century. Loudon used popular publications such as the Gardener’s Magazine as a utilitarian, rational form of recreation for all social classes. In reality, tension existed over the use of the new green spaces. At the Nottingham Arboretum in 1857, there was little evidence of botanical education reaching the lower classes. Footballs were kicked, trees damaged, plant labels stolen and worst of all, amorous activities occurred in the foliage. Arboretums persisted, but their own popularity and subsequent clamour for access diminished their original scientific purpose.

The British Arboretum is more than another history of green spaces. The authors reach beyond the boundaries of the arboretum, engaging with key themes in British cultural and scientific history in an informative and accessible manner.

Paul A. Elliot, Charles Watkins, Stephen Daniels, The British Arboretum (London: Pickering & Chatto, 2011) is available at:


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