In a context defined by the internationalisation of educational policies and the supranational nature of school programmes, we highlight the desirability of promoting local strategies for teaching environmental sustainability in order to contribute to the formation of global citizenship in children. Based on the experience of a horticultural curricular project in a school in northern Spain, the aim of this article is to reflect on the need for socio-educational communities to transform the objectives of environmental education into tools with which children can co-responsibly build connections to modify or enrich their everyday concepts of caring for the planet. To do this, semiotic analysis of different official school documents is used as a key methodology. Our findings invite consideration of the fact that pedagogies designed to train children in global citizenship competencies should not be limited to the classroom or to reproducing the proposals of institutional documents. Rather, they should be based on the prior knowledge and experiences of all members of the community, above all, of the children. From this perspective, the promotion of empirical learning situations is essential for the acquisition of meaningful and appropriate environmental contents, in the sense that they allow children, as future global citizens, to recognise the ethical repercussions of their own actions and decisions.