[1][2][3] considered one of the United Kingdom's leading amateur apple breeders.
He specialised in breeding new apple varieties,[4] especially own root trees, and was awarded the Royal Horticultural Society Associate of Honour in 1988 for his contributions to pomology.
[5] The varieties he propagated at the Brogdale Horticultural Experimental Station include popular British garden apples such as: Trees developed by Ermen, such as Scrumptious, have received the Royal Horticultural Society's Award of Garden Merit.
[2] He argued that the artificial propagation of two different types of tree created a degree of incompatibility.
Since the turn of the millennium this research has been adopted both commercially and academically with a view to producing healthier and longer living fruit trees.