Airway eosinophilia is a hallmark of allergic asthma and understanding mechanisms that promote increases in lung eosinophil numbers is important for effective pharmaco-therapeutic development. It has become evident that expansion of hemopoietic compartments in the bone marrow promotes differentiation and trafficking of mature eosinophils to the airways. Hematopoietic progenitor cells egress the bone marrow and home to the lungs, where in-situ differentiative processes within the tissue provide an ongoing source of pro-inflammatory cells. In addition, hematopoietic progenitor cells in the airways can respond to locally-derived alarmins, to produce a panoply of cytokines thereby themselves acting as effector pro-inflammatory cells that potentiate type 2 responses in eosinophilic asthma. In this review, we will provide evidence for these findings and discuss novel targets for modulating eosinophilopoietic processes, migration and effector function of precursor cells.