The second annual summit brought together more than 1,000 people, including educators, farmers, nonprofit officials and restaurant owners.
"We are trying to build a community to help each other and to grow sustainable food," said Lisa Ott, president of North Shore Land Alliance, lead sponsor of the 12-hour summit, which included workshops, demonstrations and exhibits.
One of the keynote speakers was former professional basketball player Will Allen, who talked about the importance for all people, rich and poor, to have equal access to fresh, healthy food.
Allen, 63, is the founding chief executive of Growing Power, a national nonprofit and land trust based in Milwaukee that supports inner city and suburban food programs in underserved communities.
"I love growing food for people," said Allen, whose parents were sharecroppers in South Carolina until they bought a small vegetable farm in Maryland. "It is about social justice and getting healthy food to everybody."
Long Island groups have been focused on growing food for charities and food pantries, officials said.
The Unitarian Universalist Congregation at Shelter Rock is planning to turn an acre of the Manhasset church's property into a community garden to grow vegetables year-round.
Half of the produce is to be donated to the Hempstead-based Interfaith Nutrition Network, which helps feed homeless families.
"There are so many people who never had organic food, and it is about time they got a taste," said Elaine Peters, program coordinator for the church's Green Sanctuary Committee.
The Crossroads Farm at historic Grossmann's Farm in Malverne also donates produce to local pantries, said Jo Walker, a volunteer for Nassau Land Trust, which manages the farm. The group is also trying to get more children involved in farming through education programs.
"We want them to see you can grow food in your own backyard no matter what age," Walker said.