Over the last two decades, tree planting has been viewed as a silver bullet to some of the world’s most pressing social and environmental issues, most notably climate change. This is especially the case in sub-Saharan Africa, which has seen a proliferation of tree planting projects and targets. Yet, seeing tree planting as a solution to environmental and social issues has a long history. In this thesis, I analyse the political ecology of tree planting in Kenya. I build on the concept of the political forest, the notion that ‘forests’ are produced through political as much as biophysical processes.

I focus on three key dynamics: (i) the changing priorities of the Kenyan state towards tree planting since independence; (ii) the construction and agency of Kenya’s national tree planting targets and forest metrics; and (iii) how a carbon forestry programme in central Kenya ‘hits the ground’ within the broader political, ecological and economic context of Kenya.

My findings show that there is a long history of the Kenyan state reaching for tree planting to solve complex socio-environmental issues. I demonstrate, however, that the motives and narratives underpinning tree planting have changed over time, as well as where tree planting is expected to occur and who is expected to plant trees. The state’s emphasis has changed from the planting of commercial plantations within state forests for economic development to the idea that farmers outside state forests must be the principal agents of tree planting to combat a wide range of issues, such as climate change and wood fuel production.

Next, I show the power of the 10 per cent tree cover target, which currently informs tree planting in Kenya. I show how the target is fundamentally arbitrary and partly based on a history of comparing Kenya’s forest cover to that of other nations. The 10 per cent target has been produced and reproduced by numerous actors in Kenya for decades. I show the complexities of how the target is defined and measured and the manner in which it interacts with other forest metrics.

Finally, I analyse a specific on-farm tree planting for carbon credits project near Mount Kenya to understand what tree planting looks like ‘on the ground’ in Kenya. Although fast-growing trees are by far the most popular choice of tree for farmers to plant, this is not being driven solely by carbon. Indeed, the project must contend with the other values of trees that have been impacted by the broader politics of tree planting in Kenya. Here I show that the material landscape of tree planting around Mount Kenya is a result of a complex web of relations.