His achievement at the John Innes was to turn it, during a period of government disinvestment, from an institute for plant research into a centre of international scientific excellence. Woolhouse believed that the problems of feeding the world and the protection of the environment could be solved by the application of scientific research, and he encouraged international co-operation to that end. In his final six years at the Waite, he turned it into the premier southern hemisphere plant research institute, providing vital training for biologists throughout the Far East.
He was born in Sheffield in 1932, and brought up in a small house full of ferrets, whippets and racing pigeons. His father, a schoolmaster, collected birds' eggs and was a keen allotment gardener, an interest he passed on to Harold, his eldest child, who helped him in the garden and collected butterflies and moths on his own account. The extended family was close by with the grandparents next door and during the Second World War it was their cellar they all used as an air-raid shelter.
Harold Woolhouse went to a local school and his love of "botanising" began there with walks over the common, encouraged and inspired by his chemistry master, Alfred Ridler. When he left he did not apply to university (he would have been the first in his family to do so) but worked for a year as a market gardener, thinking to study Horticulture at college. At the same time he tried and failed to get a job at the John Innes. The year over, he took up a place at Reading University to study Horticultural Botany instead.
Here began his academic career, which, though Woolhouse considered himself a late developer, resulted in his being awarded the Chair in Botany at Leeds University at the age of only 36.
He excelled at Reading and, advised by Professor Tom Harris, undertook a PhD on leaving. He typically chose to pursue his studies further afield, at the University of Adelaide. There he met his wife Leonie, an undergraduate who, by coincidence, was living in Urrbrae House, later the focal point of his directorship of the Waite.
After four years in Adelaide, he brought Leonie home to England, where they intended to stay for no longer than two years before returning to Australia. In the meantime he started on the academic ladder.
Woolhouse began as Junior Research Fellow at Sheffield University in 1960 and worked his way through the various grades of lecturing, with a sabbatical six months at the University of California at Los Angeles, studying plant senescence, in 1967. He left Sheffield as Senior Lecturer in 1969 to take up the Chair in Botany at Leeds.
Here his openness and energy were put at the service of his PhD students, many of whom now hold professorships themselves. Woolhouse had an almost photographic memory, for which he apologised, but he retained names and backgrounds with ease and had a genuine interest in everyone around him. As a leader he responded best to challenge rather than passive agreement. His democratic instincts ran deep to the extent that later at the John Innes he abolished the director's parking space. As one of his students remembers, he didn't tell people what to do but generated ideas.
He was an innovator. He introduced computer networks at Leeds. He also travelled. In 1973 he went with an expedition down the Zaire River, and three years later embarked on another expedition down the Amazon. He kept diaries of these periods.
Woolhouse took over the John Innes Institute in 1980, his original application being lost down the back of the photocopier. He brought in part of the Plant Breeding Institute under the title of the Cambridge Laboratory and negotiated with the Gatsby Foundation to have the Sainsbury Laboratory installed there. A new library was built under his directorship and he put in train the transfer of the Nitrogen Fixation Laboratory from Brighton to Norwich.
At 60, as a civil servant, he would have had to retire but chose instead to take up the Directorship of the Waite Institute in Adelaide in 1990. His dynamic leadership there was widely acknowledged, as were his achievements in bringing together important institutions and state resources.
It was at Adelaide that he developed the lung tumour that was to spread and kill him, though the process took 16 months longer than the two months first feared. He had been in the last stages of building a A$70m plant research laboratory. The new library he had built at Adelaide has been named in his memory.
Harold Woolhouse loved music and poetry, but could converse on all topics with all people. His own gardens at Leeds, and latterly at Wymondham, in Norfolk, were his great love. They evolved rather than obeyed any strict plan, almost like Gothic fantasies. He preferred autumn above other seasons and delighted in old roses. In his last days he was at home and asked that family and friends should read poetry to him, chiefly from Donne, Eliot and the late Hardy.
Harold William Woolhouse, botanist: born Sheffield 12 July 1932; Lecturer and Senior Lecturer, Sheffield University 1960-69; Professor of Botany, Leeds University 1969-80; Director, John Innes Institute and Professor of Biological Sciences, University of East Anglia 1980-86, Director of Research, AFRC Institute of Plant Science Research and Honorary Professor 1987-90; Director, Waite Agricultural Research Institute and Dean, Faculty of Agricultural and Natural Resource Sciences, University of Adelaide 1990-96; married 1959 Leonie Sherwood (two sons, one daughter); died 19 June 1996.