Science and the Garden has been written primarily for students of horticulture, but we expect that it will also be of interest to amateur gardeners and professional growers who would like to understand more about the science that underlies horticultural practices.
Most conventional gardening books concentrate on how and when to carry out horticultural tasks such as pruning, seed sowing and taking cuttings. In contrast, the aim of the present book is to explain in straightforward terms some of the science that underlies these practices. We address such diverse questions as: why are plants green? Why should one cut beneath a leaf node when taking cuttings? Why do plants need so much water? Why is light so important and what effect does it have on plant growth? How do plants detect drying soils and how is growth modified to improve their survival chances? Why are plants more resistant to freezing in the autumn than in spring? How do plants detect seasonal changes in their environment? Why do chrysanthemums flower in the autumn and onions produce their bulbs in the summer?
The first part of the book is concerned with some fundamental principles. Chapter 1 describes the structural features of the plant, and introduces biochemical and physiological processes such as photosynthesis and water and solute transport, which are expanded on in later chapters in relation to particular aspects of horticultural practice. Chapter 2 introduces the often difficult question of how plants are named. Plant names are a problem for many gardeners and this chapter explains the structure of plant nomenclature in simple terms; it outlines the rules for naming plants, discusses why names sometimes change and, most importantly for the gardener, what is being done to achieve stability in plant nomenclature.
It is often thought that genetic modification (GM) is the ‘new' thing in horticulture, but the fact is that most plants grown in gardens (except weeds) have been genetically manipulated in the sense that their genes differ from those of their wild relatives. ‘Designing Plants' (Chapter 3) explains how new plants have been developed through cross-breeding and selection processes that have been going on for centuries. The chapter concludes with a look towards the future by showing how new plants can be ‘designed' by introducing specific genes using GM technology.
The remainder of the book is more immediately concerned with the practices of horticulture. With the exception of a few aquatics, gardening depends on the soil and Chapter 4 describes the different types of soil, explains how to recognise them and introduces the science underlying soil management practices. Water conservation is an important consideration in many gardens and may well become more important with climate change. The selection of suitable plants is itself a form of water conservation by the gardener and Chapter 5, ‘Choosing a Site', describes how certain plants are adapted to grow in dry conditions. All gardens have shady areas and Chapter 5 also explains how plants are able to detect shade from trees and neighbouring buildings and modify their growth accordingly. It ends with advice on how to choose plants for particular situations using scientific principles.
‘Raising Plants from Seed' (Chapter 6) and ‘Vegetative Propagation' (Chapter 7) are basic horticultural practices. These two chapters discuss the science underlying embryo development, seed maturation and ripening, dormancy and how it may be broken, and the storage of seeds. They also look at vegetative propagation, such as taking cuttings, layering and micropropagation, with special emphasis on the physiological processes underlying these practices, most notably the hormonal control of growth and development. The science of grafting isalso considered.
Once plants have been propagated and the site hasbeen selected with due consideration for soil and aspect, the choice of a particular plant for that situation is usually determined by factors such as colour, size and shape, topics that are covered in Chapter 8. The choice of suitable plants also depends on factors such as the time of flowering and, for edible crops, the yields of storage organs such as potato tubers and onion bulbs. The time at which plants enter dormancy and increase their resistance to freezing conditions often determines their ability to grow and even to survive in a particular locality. These processes are largely governed by seasonal factors, although they may be modified by local conditions. Chapter 9, ‘Seasons and Weather', focuses on such seasonal factors as day length and temperature and explains how these are sensed by the plant and how the information is translated into the observed displays. Gardening in the greenhouse is a specialised form of gardening, requiring knowledge of how the physical conditions of the greenhouse interact with the physiology of the plant if optimum yields are to be achieved. Such interactions and their implications for successful greenhouse management are discussed in detail in Chapter 10.
As all gardeners will be aware, no matter how great their horticultural skills, pests, diseases and weeds are a constant problem and can often cause disaster. Chapter 11, ‘Controlling the Undesirables', describes how such organisms can be recognised, how they affect plant growth and what strategies are available for combating them. Throughout this chapter the emphasis is on integrated management of pests, diseases and weeds and the use of methods that are environmentally friendly.
Harvesting the flowers, fruit and vegetables that are the product of many hours' labour can be the most satisfying of tasks for the successful gardener. Fittingly then the final chapter in the book considers the physiological basis of the maturation process, and discusses the best ways of harvesting and storing flowers, fruit and vegetables to ensure maximum quality, storage life and flavour.
The book has been edited and written by past and present members of the Royal Horticultural Society's Scientific and Horticultural Advice Committee, past and present members of the scientific staff of the Society, and other specialists. The contents reflect the particular interests of the authors, and their judgement as to the scientific information that is likely to be of greatest importance to gardeners and horticulturists.
We would like to thank all those who have contributed to the volume by writing particular chapters, by commenting on draft chapters and by giving their general support. We also wish to thank Mrs Joyce Stewart, Royal Horticultural Society Director of Horticulture, for allowing her staff to participate in the project and for arranging a grant from the Royal Horticultural Society towards the cost of printing the colour plates. DSI also thanks Napier University for its support during his tenure of a Visiting Professorship there, Mrs Janet Prescott for managing the project and contributing significantly to the editing process, and Mrs Jane Stevens, of St Catharine's College, Cambridge, for her assistance during the final stages of editing the volume.
David S. Ingram
(Cambridge)
Daphne Vince-Prue
(Goring-on-Thames)
Peter J. Gregory
(Reading)