Tree cultivation and management are a common form of land use in high-potential areas of Kenya. While some of these practices are related to economic considerations, such as markets and prices for specific tree products, others were derived from or developed in parallel with customary practices. This article traces the origins of contemporary demarcation practices in Kikuyu areas of Kenya, involving the planting of trees in hedges and windrows, from their customary antecedents. Customary law prescribed clear mechanisms for demarcating land to which rights of use had been acquired. These mechanisms, characterised principally by the planting of particular trees on the boundaries of land holdings, were given limited recognition by the colonial administration, and were subsequently incorporated (without any clear awareness of their customary role) in the contemporary body of land law which emerged as a result of the land reforms of the early 1960s. Land reforms tended to obscure customary distinctions between rights of control to trees and rights of use and access, by equating rights of control with rights of ownership. The result has been that rights of use and access, which had been guaranteed to the landless under customary law, were, for the most part, eliminated.