This article explores local knowledge of ecological interactions held by smallholder coffee farmers in the Central Highlands of Kenya. The area is in the vicinity of the Aberdare Forest Reserve, a biodiversity hotspot, but coffee farms were shown to harbour only a few tree species in abundant numbers, due to historical developments in the coffee sector. In order to increase tree diversity on coffee farms, an understanding of shading impacts on coffee productivity is required, also the livelihood benefits farmers can expect to accrue from incorporating trees into their coffee plots. For change to happen on the ground however, different farming contexts need to be taken into account and advice tailored accordingly – this represents a change to the way recommendations are currently made.