- American Association of Arboreta and Botanic Gardens
- American Horticultural Society
- Australian Institute of Horticulture
- Botanical Society of America
- DEFRA
- Fairchild Tropical Garden
- Garden Writers’ Guild
- Henry Doubleday Research Association (HDRA)
- Horticultural Trades Association
- Institute of Biology
- Institute of Horticulture
- Instituto de Pesquisas Jardim Botânico do Rio de Janeiro
- International Bulb Society
- International Association For Plant Taxonomy
- International Plant Names Index
- International Plant Propagators Society
- International Society for Horticultural Science
- KAVB
- Missouri Botanical Garden
- National Botanic Garden of Wales
- National Council for the Conservation of Plants and Gardens
- New Zealand Institute of Horticulture
- Pershore College of Horticulture
- Professional Gardener’s Guild
- Queen Elizabeth II Botanic Park
- Royal Botanic Gardens, Kew
- Royal Horticultural Society
- Royal New Zealand Institute of Horticulture
