By Jane McMorland-Hunter, Sue Dunster
By Carol Klein
By Gay Search, Delia Smith
By Greenwood, Pippa
By James L. Brewster (Horticulture Research International, Wellesbourne, UK)
By Pete Brown
By Dickinson, Becky, Collins Big Cat
By Royal Horticultural Society
By Richards, Alison, Morgan, Joan, Dowle, Elizabeth
By M.M.Vilmorin- Andrieux
By Pollock, Michael
By Peel, Lucy
By Robert Hart
By John Evelyn