Hall, who died this week of cancer aged 83, was instrumental in setting up the British Heather Growers Association and the Woking Nursery Exhibition.
He spent 40 years working at Windlesham Court Nurseries in Bagshot, Surrey, and pioneered the growing of Erica carnea 'Whitehall'.Hall is survived by his wife Jean and four children.
Head died on 5 December. His company, Denys E Head, owned Forest Lodge Garden Centre, Garden Style Nursery and Birdworld at Farnham, Surrey.
He started his career in 1947 as a vegetable grower near Milford in Surrey and ran a 21ha farm with his wife Hilary for 30 years.