National Association of Landscape Professionals
This is the country’s largest association of professional landscapers (~100,000 members); the organization offers support and functions as a clearinghouse of pertinent information. Loveyourlandscape.org is a site on NALP, which provides “helpful information for the public about caring for their lawns and landscaped areas.”
New York State Flower Industries
Created in 1945, they represent horticulture and floriculture professionals throughout New York State.
Land Improvement Contractors of America
This association provides members with certifications, as well as educational and leadership opportunities.
New York State Nursery Landscape Association
They “provide sound education of horticultural practices.” NYSNLA also offers the CNLP — Certified Nursery and Landscape Professionals certification — for individuals who passed the exam. They have undergone intensive training in the fields of pests and diseases, weed control, soils, fertilizer, tree pruning, and plant identification.