Thomas Knight, one of Britain’s most influential botanists, was born at Wormesley Grange in Herefordshire. He was the son of a parson and the younger brother of Richard Payne Knight, the classical scholar, whose main thrust of work related to theories of the Picturesque. He was born at Wormesley Grange, five miles north-west of Hereford in Herefordshire, the second son of Rev. Thomas Knight (1697–1764) of Wormsley Grange, Rector of Bewdley, Worcestershire, and Ursula (née Nash), a daughter of Frederick Nash of Dinham, Shropshire. He was the heir of his unmarried elder brother the art connoisseur Payne Knight (1750–1824), MP, who had been the heir not only of their father but also of their uncle Richard II Knight (1693–1765) of Croft Castle and of Downton, and who had re-built Downton Hall as the surviving Gothic revival style Downton Castle. Richard II Knight as the eldest of five sons was the heir of his father Richard I Knight (1659–1745), of Downton, a wealthy ironmaster of Bringewood Ironworks, on the Downton estate, who founded the family's great fortune.
Thomas, who was largely self-taught, was educated at Balliol College, Oxford. After graduation, he took up the study of horticulture. In 1795 he published the results of his research into the propagation of fruit trees and the diseases prevalent among them. He used 10,000 acres (4,000 ha) of land he inherited and built a curvilinear greenhouse for breeding plants including strawberries, cabbages and peas. In 1797 he published his Treatise on the Culture of the Apple and Pear, and on the Manufacture of Cider and Perry, a work which passed through several editions. His breeding experiments, between identified plant varieties, led to new cultivars of apples. He would select among hundreds of seedlings to pick out the few with improved characteristics. For example, the Siberian Harvey cider apple was among about 4 seedings he kept from 300 crosses. His work on the specific gravity and thus sugar content of apple juice were important to development of the UK cider industry. He also devised new horticultural and agricultural equipment such as a new turnip seed drill, razor sharpener and pineapple pit.
Knight's enduring interest in animal and plant life led him to create a walled garden and modest range of hothouses at his farm at Elton Hall in 1786, where he concentrated on plant growing and livestock breeding. He may well have remained thus but for two significant events.
The first was that Sir Joseph Banks of the London Horticultural Society (later the Royal Horticultural Society) noted the intelligence of Knight’s written work and encouraged his experiments with plant physiology and breeding. In April 1795, Knight read his paper to the Society entitled, 'The grafting of Fruit Trees'. He was aware that many of Britain’s older fruit varieties were in decline, notably apples and pears, as well as cherries, plums and nectarines. Furthermore, he had observed that disease could be passed on by grafting and that poor or irregular cropping of older varieties were affecting trade volumes during a period of particular difficulty - namely, Britain’s lengthening war with France. He regularly corresponded with Banks and published his Treatise on the Culture of the Apple and Pear in 1797.
The second event was that in 1809, Thomas Knight came into possession of the considerable estate of Downton Castle from his brother. With the benefit of his pioneering skills in plant breeding and 10,000 acres of land at his disposal, Knight continued to develop disease-resistant cultivars of tree fruits in their many thousands. His work also raised stocks of potatoes, peas and cabbages to new standards of excellence. He is perhaps best remembered for the Downton Strawberry, or 'Knight's Seedling'.
Knight performed new physiological experiments on plants. He investigated the effects of gravity on seedlings and how decay in fruit trees was passed on by grafting. In many respects his work looked back to that of Rev. Stephen Hales. His goals were always strictly practical, aiming to improve food plants by breeding for better qualities. In the mid-19th century, the Downton strawberry was a popular strawberry in Britain, until it was eclipsed by modern strawberry hybrids at the turn of the century.
It is not widely known that he studied variation in peas and made similar observations to Mendel, but he failed to make the same imaginative leap about the relationships between these changes. Knight intentionally shut himself off from outside scientific influences but did maintain correspondence with others around the world as well as meeting some of them during his annual visits to London. He refused to read anyone else's scientific papers until Sir Joseph Banks, with whom he had a voluminous correspondence, persuaded him to do so. Knight also corresponded with Sir Humphry Davy.
His research was, however, read and appreciated by his contemporaries. Charles Darwin acknowledged Knight's breeding experiments in The Origin of Species. He was elected a Fellow of the Royal Society in 1805 and awarded the Copley medal in 1806. He was given honorary membership and awards from agricultural and horticultural societies in Europe, Russia, the USA and Australia. Distribution of Knight's apple seeds and scions to the USA helped develop its apple industry.
Banks, president of the Royal Society, had recognised Knight's contributions to science and asked him to join the Horticultural Society, as it was then known. After the death of the first president, George Legge, 3rd Earl of Dartmouth, Banks proposed Knight as president. In 1864 the Society received a royal patent from Albert, Prince Consort, which permitted it to be known as the Royal Horticultural Society. Banks called upon Knight to write a "prospectus" for the society (what would now be called a mission statement), outlining its functions and purpose.
Younger members of the Society were inspired by his example, such as Thomas Laxton. Laxton adopted methods of careful observation and practical goals that resulted in improved varieties of apples, peas and sweet peas among many others, together with a thriving seed business.
The standard author abbreviation T.Knight is used to indicate this person as the author when citing a botanical name.
Knight's published and practical work encouraged landowners, commercial nurserymen and gentlemen gardeners to adopt his findings and to plant new, vigorous varieties with great success. No less a scholarly work, but with exquisite illustrations was Knight's second volume, Pomona Herefordensis, published in 1809. Two years later he was rewarded with the office of President of the London Horticultural Society, a position to which he was re-elected annually until his death.
Thomas Knight was arguably the most innovative botanist of his era. Although his theory of 'degeneration' of fruit has since been disproved by modern methods, his observations of phototropism (the tendency of a plant to turn towards a source of light) and the cambium (the cellular plant tissue responsible for the increase in girth of stems and roots), and his studies on the ascent and descent of sap, have long been accepted facts of plant physiology.
He was held in high regard by contemporary practitioners and writers, notably Charles McIntosh, who wrote in 1826 that 'To the exertions of Knight...we are indebted, for many of our best fruits, and not only the improvements of our native sorts, but also for the introduction of several foreign kinds'.
Professor John Lindley, delivering his introductory lecture to the University of London on 30 April 1824 was yet more fulsome in his praise for Knight: 'Nine-tenths of the most important discoveries that have been made in modern Horticulture, especially the art of regulating and adapting artificial climate to vegetation, are due to the botanical knowledge of the most distinguished vegetable physiologist of this kingdom; whose successful attempts at applying science to practice have recently been crowned, if I may so express myself, by the complete subjugation of the unmanageable constitution of the Pine-apple'.
In 1991, a little over 150 years after Knight's death in 1838 - he was buried in the churchyard of St Mary's Church, Wormsley, where his surviving chest tomb is a grade II listed structure - Tim Smit and John Nelson patiently restored the ‘lost’ gardens of Heligan, Cornwall. In rebuilding the pineapple pits to a productive standard, they chose to work to the designs that had been drawn up by Knight in 1822, which had so impressed Lindley and others in their day. The first ripe specimens from Heligan were cut just five years later.
He married Frances Felton, a daughter of Humphry Felton of Woodhall in Shropshire, and they had the following children:
- Thomas Andrew Knight (d. 29 November 1827), eldest son and heir apparent, who predeceased his father without any children.
- Frances Knight (d. 1874), a botanist, archaeologist, writer and artist, who in 1812 married Thomas Pendarves Stackhouse Acton (d. 1835) of Acton Scott; they did not have any children.
- Elizabeth Knight (d. 3 August 1860), who in 1828 married Francis Walpole (d. 1861), son of Hon. Robert Walpole, son of Horatio Walpole, 1st Baron Walpole of Wolterton, brother of Robert Walpole, 1st Earl of Orford (1676–1745), first Prime Minister of Great Britain. They had several children.
- Charlotte Knight (c. 1801–14 May 1842), a notable horticulturalist, who in 1824 married Sir William Edward Rouse-Boughton, 2nd and 10th Baronet (1788–1856), a member of parliament for Evesham in Worcestershire. She was the heiress of her father's Downton Castle estate, although the inheritance was unsuccessfully contested by her senior male cousin (John Knight (1765–1850), of Lea Castle, Wolverley, the pioneering developer of the Forest of Exmoor in Somerset) in the lengthy and famous law suit of Knight v Knight (1836–40).
Knight, T, A (1797) Treatise on the Culture of the Apple and Pear, London
Knight, T, A (1809) Pamona Herefordensis, London
Numerous papers in the Royal Horticultural Society collection
Beauman, F. (2005) The Pineapple, King of Fruits Chatto & Windus, London, pp. 253
Darrow, G, M (1965) "The Strawberry: History, Breeding and Physiology" www.nal.usda.gov/pgdic/Strawbe...
History of Horticulture www.hcs.ohio-state.edu/hort/hi...
McIntosh, C (1828) The Practical Gardener and Modern Horticulturalist Vol 1. Thomas Kelly, London
The Peerage.com http://thepeerage.com p17531.htm#i 175307
www.rootsandleaves.com (Knight family history/Wormsley Grange)
Shull, C.A & Stanfield, F (1939) "Plant Physiology, Thomas Andrew Knight in Memoriam". Vol 14. No.1 Univ. of Chicago www.plantphysiol.org/cgi/repri...
Stearn, William (1999) John Lindley 1799-1865, Gardener, Botanist and Pioneer Orchidologist Antique Collectors Club, London pp. 85
Contributor: Jonathan Cass