2019 Conference Climate Change & Gardens 6. John Edmiston

From 2019: Plant choices in a changing climate - Drought Tolerant Plants in a Hotter, Drier Future

An Overview of some useful taxa from the American South West John Edmiston, Director, Tropical Britain

Abstract:

In the cool temperate climate of the UK, plants-people have always aspired to introduce and grow new plant taxa. For many decades, one of the major trends in British gardens has been the use of perennials. Now - with a changing climate and an increasing pattern of warmer weather - mesic, water-thirsty, herbaceous plants are no longer the most sustainable choice.

Drought-resistant perennials and more modern, less high-maintenance perennial plantings may represent only part of the way forward. The UK climate is a complex picture with regional differences and differing wind directions bringing our famously changeable weather but a pattern of hot, dry summers (often following on from a hot, dry spring) has become more prevalent - particularly in the south. Extended heat-waves challenge the most ardent gardener. Mediterranean planting is often quoted as being a model for the future UK garden but the flora of the American South-West - in particular, from the mountains - may be a more useful analogue with plants there subjected to extremes of cold and heat, wet and dry. At high elevations, plants experience extended periods of sub-zero temperatures and wet snow-melt followed by long hot summers. John explores the use of xeric plants and some of the more suitable taxa for UK conditions and suggests that a fusion planting - incorporating xeric plants that are hardy in the UK together with drought-resistant perennials - may be the 'mixed border' of the future. While many xeric plants have the disadvantages of being monocarpic or spiky or both, John outlines his constant search for the Holy Grail - xeric plants that are hardy, polycarpic and non-spiky!

John Edmiston is a Director of Tropical Britain, an online plant nursery that specialises in hardy exotics with a focus on the changing climate. A self-confessed plantaholic, he built his first glasshouse at the age of twelve and has been unable to

stop growing plants ever since. John is a strong believer in the part that both gardeners and nurseries can play in

botanical conservation.