Brooklyn Botanic Garden -  Join ASAP
www.bbg.org

New York Botanic Gardens -“Homeric!”
www.nybg.org

Green Guerillas – Community Urban Gardening  at its best
www.greenguerillas.org

Metro Hort New York - Cartalk for plant professionals
www.metrohort.org

Cornel Cooperative Extension - Soil Testing, plant info, ignore anything they say about pesticides unless it’s don’t use.    
www.cce.cornell.edu

Garden info - 
www.gardening.cornell.edu

New York City Parks Department
www.nycgovparks.org