In the rush toward securing food supplies and saving nature, agroecosystems such as smallholder farming landscapes in the tropics appear at times to be a missed opportunity.1 Efforts tend to focus instead on two distinct pathways in separate portions of the landscape: efficient agriculture in larger scale farmlands and wild nature for conservation. The mixed tropical landscapes managed by smallholder farmers tend to be seen as neither very productive, nor good for nature. For conservationists in particular, a key obstacle is that these agroecosystems host many introduced or invasive species, instead of just native or endangered species. In this article, we argue that the arrival of alien plants in these ever-changing "melting-pot" landscapes can contribute to people's adaptation to social and environmental changes, to a diversification of livelihoods and habitats, to avoided deforestation, to biodiversity conservation, and finally to sustainability. Based on a three-part analytical framework applied to several case studies, we argue that more resources should be dedicated toward understanding, protecting, and enhancing tropical smallholder farming systems, and that introduced plants should not be an obstacle to this.