SAN DIEGO — At the Saturday farmer’s market in City Heights, a major portal for refugees, Khadija Musame, a Somali, arranges her freshly picked pumpkin leaves and lablab beans amid a United Nations of produce, including water spinach grown by a Cambodian refugee and amaranth, a grain harvested by Sarah Salie, who fled rebels in Liberia. Eaten with a touch of lemon by Africans, and coveted by Southeast Asians for soups, this crop is always a sell-out.

Among the regular customers at the New Roots farm stand are Congolese women in flowing dresses, Somali Muslims in headscarves, Latino men wearing broad-brimmed hats and Burundian mothers in brightly patterned textiles who walk home balancing boxes of produce on their heads.

New Roots, with 85 growers from 12 countries, is one of more than 50 community farms dedicated to refugee agriculture, an entrepreneurial movement spreading across the country. American agriculture has historically been forged by newcomers, like the Scandinavians who helped settle the Great Plains; today’s growers are more likely to be rural subsistence farmers from Africa and Asia, resettled in and around cities from New York, Burlington, Vt., and Lowell, Mass., to Minneapolis, Phoenix and San Diego.

With language and cultural hurdles, and the need to gain access to land, financing and marketing, farm ownership for refugees can be very difficult. Programs like New Roots, which provide training in soil, irrigation techniques and climate, “help refugees make the leap from community gardens to independent farms,” said Hugh Joseph, an assistant professor at the Friedman School of Nutrition at Tufts, which advises 28 “incubator” farms representing hundreds of small-scale producers.