The present invention is a post yard hydrant with controlled adjustable flow. The post yard hydrant includes a valve housing located below ground level for connection to a water supply under pressure, a head portion with an integral discharge nozzle positioned above ground level, and a casing portion with a first end connected to the head portion and a second end connected to the valve housing. The post yard hydrant further includes an operating rod disposed in the casing portion for reciprocation therein and an operating means configured to interact through a flow control linkage to reciprocate the operating rod. The flow control linkage is adapted to adjust water flow from a trickle level to a full pressure level.