Biodiversity needs to be preserved to ensure food security. Border zones create high but vulnerable biocultural diversity. Through reviewing scattered historical data and documenting the current use of wild food plants among people currently living in historical Setomaa and Võromaa parishes, we aimed to identify cross-cultural differences and diachronic changes as well as the role borders have played on the local use of wild plants. The Seto have still preserved their distinctive features either by consciously opposing others or by maintaining more historical plant uses. People historically living in Setomaa and Võromaa parishes have already associated the eating of wild plants with famine food in the early 20th century, yet it was stressed more now by the Seto than by Estonians. Loss of Pechory as the center of attraction in the region when the border was closed in the early 1990s brought about a decline in the exchange of knowledge as well as commercial activities around wild food plants. National support for businesses in the area today and the popularity of a healthy lifestyle have introduced new wild food plant applications and are helping to preserve local plant-specific uses in the area.