Spatial Distribution of Greenhouse Commercial Horticulture in Kenya and the Role of Demographic, Infrastructure and Topo-Edaphic Factors

Greenhouse commercial horticulture in Kenya started more than two decades ago and has evolved to be a significant sector to the national economy. So far no studies have explored the spatial patterns and dynamics of the area under greenhouse cultivation. Google Earth archives alongside data from various portals provided an opportunity to study those farms’ spatial distribution. The roles of selected topo-edaphic, infrastructure and demographics factors that might influence current location within sub-watersheds in central highlands of Kenya are also examined. Results reveal a non-uniform spread with two high clusters; one in the semi-arid sub-watersheds 3AB shared by Kajiado and Machakos districts and the other is in sub-humid sub-watersheds 3BA shared by Kiambu and Nairobi districts. Multivariate linear regression analysis reveals four statistically significant parameters; population density (p < 0.01), number of dams (p < 0.01), average rainfall (p < 0.01) and average slope (p < 0.05) in predicting the number of greenhouse farms. Soil attributes are not significantly related with greenhouse farming in this study. Findings indicate that greenhouse commercial horticulture is heterogeneous, and rapidly expanding beyond the central highlands towards marginal semi-arid zones in Kenya. These findings are applicable in policy and decision making processes that aid the horticulture sector’s progress in a sustainable manner.