A tree injection apparatus includes a pump coupled with a fluid reservoir that holds a treatment solution under pressure generated by the pump. At least one fluid conduit is provided to have a first end coupled with the pump and a second end coupled with a valve assembly. A feeder tube is releasably engaged at the valve assembly, where the feeder tube is configured to engage a drilled hole extending into vascular tissue of the tree receiving treatment. The pump releases the pressurized treatment solution through the fluid conduit and to the feeder tube at a desired pressure, so as to generally coincide with the absorption rate of the vascular tissue. The feeder tube may be released from engagement with the valve assembly, so as to allow cleaning of the feeder tube of debris, pathogens, and spores before being installed on another tree.