This paper contributes to wider debates on the dominant factors determining the emergence and sustainability of intermediate systems of forest management in developing countries. The theoretical framework and propositions for analysing tree integration in homestead farms are presented, with reference to southeast Nigeria. The paper argues that, first, at the household level, livelihood strategies constitute the main determinant of the decision to integrate trees in homestead farms. Secondly, induced innovation has a wider and more significant role at the community level than at the household level in encouraging the integration of trees in farms. Thirdly, the sustainability of observed patterns of tree integration is influenced by the interaction of environmental, ecological, political, economic and social factors. Based on these propositions, the paper analyses the internal (household) and external (wider community) factors influencing tree integration in homestead farms in southeast Nigeria.