Grows in shallow, calcareous soils on hillsides and along marshes and coastlines. Once formed almost pure stands with an estimated density of as much as 500 trees to the acre (Groves
1955). Fruits ripen in September and October (Britton 1918). Germination rates are good where the habitat allows, taking into account the vastly reduced adult population. The main seed disseminator seems to be the Starling, Sturnus vulgaris
, which became naturalized in the 1950s, increased explosively in the 1960s, and is highly mobile. Natural self seeding occurs mainly in unmanaged coastal scrubland and exposed hilltops where the otherwise dominant invasive flora is sufficiently stunted or sparse due to wind and salt spray exposure to allow germination and juvenile growth of junipers to occur. In such areas a new forest cover is gradually developing where the juniper is the dominant emergent tree. It is estimated that the natural pre-disturbance generation length is 25 years - this is based on the length of time taken for a naturally regenerating stand of trees to reach harvestable age.