In AS-PTAs work collecting varieties of corn and beans with small farming communities, we very often find in homegardens and in the women's work areas varieties that are not used for cash crops but which are still planted because they taste or cook better or even because they are aesthetically attractive. Another interesting phenomenon observed in homegardens is the inbreeding or migration of genes amongst the varieties of a given species caused by naturally occurring cross-pollination. This process serves to enhance variability. Another important factor is the adaptation of species to extreme or specific ecological conditions in the homegardens. We have often witnessed this process in the case of medicinal plants.
Frosts are quite common during the winters in southern Brazil.
Many farm women will reserve small plots near their houses that are protected from frost and, before the onset of winter, transplant seedlings of medicinal plants that might die if left in more open areas. In this way, they are not only guaranteeing a supply of herbs for their own use during the winter but also maintaining a reserve to plant in larger areas when spring comes to replace those lost during the winter. All this experience has put homegardens on many researchers' agendas as living gene banks. They emphasise the importance of preserving homegardens as key elements in the conservation and generation of diversity in agricultural species. By the same token, work with the components or totality of agricultural biodiversity will never get past the good-intention stage unless it encompasses an active role for women.