Regional
Bedfordshire
Berkshire
Buckinghamshire
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Cornwall
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Devon
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Leicestershire
Lincolnshire
London
Merseyside
Oxfordshire
Rutland
Somerset
Surrey
Warwickshire
West Midlands
Worcestershire
Wiltshire
Yorkshire
National
Federation of City Farms & Community Gardens
National Chrysanthemum Society
National Garden Scheme
National Dahlia Society
National Gardening Association
National Rose Society
Royal Forestry Society
The Allotment & Garden Council UK
The British Fuchsia Society
The British Orchid Council
The Cottage Garden Society
The Hardy Plant Society
The Herb Society
The National Fruit Show
The National Society of Allotments and Leisure Gardens
The National Vegetable Society
International
Botanic Gardens Conservation International
Botanical Society of Britain and Ireland
International Association of Plant Taxonomy
International Carnivorous Plant Society
International Office of Allotment & Leisure Gardens
International Society for Horticultural Science
Mediterranean Garden Society
Royal Horticultural Society
Society for Conversation Biology
The Federation of European Societies of Plant Biology
The International Waterlily & Water Gardening Society
The Scottish Rock Garden Club