Provided is an orchard heater adapted especially to radiate heat directly to the bole and middle portions of the trees, the heater comprising an upright, generally elongated and cylindrical combustion chamber having formed therein a vertically extending looped main burner, a pilot burner disposed beneath the main burner, and a divider plate interposed between the former two burners. The burners are positioned such that the discharge orifice of the main burner lies in the plane of the axis of the combustion chamber and is oriented downwardly at the center of the divider plate. The discharge orifice of the pilot burner, in turn, is oriented upwardly to the bottom of the divider plate, the latter being apertured, typically with louvers which enable communication between the discharge orifices of the two burners. Upon ignition of liquid fuel supplied by the main burner in the chamber, the generated heat is initially radially outwardly directed by the divider plate, this heat being oriented in a horizontal plane. Heat impinging on the chamber wall heats the latter and is directed radially and horizontally outwardly therefrom.