Informal seed systems provide access to locally-adapted indigenous crops and constitute an essential component of sustainable production for resource-poor farmers in Southeast Asia. Research conducted with five ethno-linguistic groups in 12 villages in northern Thailand and Cambodia focuses on strengthening the indigenous informal vegetable seed system, including the conservation of knowledge surrounding that system. Through targeted village surveys and using photo card sorts to standardize responses across languages, our methodology documents and characterizes seed system species, pathways, and “germplasm gatekeepers” for indigenous annual and perennial vegetable crops important to northern Thailand hilltribe and Khmer communities. Additionally, farmer-innovated seed preservation and storage methodologies are documented, and farmer-saved seeds are tested using a village-based photovoltaic-powered growth chamber to determine baseline seed viability and vigor under local conditions. At the culmination of research in village clusters, seed and information exchange events occur that facilitate the inter-village exchange, preservation and dissemination of important genetic resources and best practices for seed saving and storage methodologies identified during the farmer community surveys. This research, which was completed in eight northern Thai villages and in four Cambodian villages, helped to build important linkages between under-represented Southeast Asia farmers of diverse ethnicities, a local innovative seed bank (ECHO Asia Impact Center), and a local university extension training system.