By Royal Horticultural Society
By Preston, G.H.
By Goold-Adams, Deenagh
By Geoffrey K. Coombs, Coombs, Geoffrey K.
By Knight, F.P.
By Brooks, Audrey, Halstead, Andrew
By Innes, Clive
By Trehane, David
By Pearson, Robert
By Potter, J.M.S.
By Cox, Peter A.
By Page, Mary, Stearn, William T.