Low　temperature　stress　is　an　important　factor　for　turf　growth　in　the　northern　high-latitude　environment.　A　thermosyphon　temperature　controlling　unit　with　a　shallow　geothermal　source　was　proposed　by　analyzing　present　techniques　to　prolong　the　turf　growing　season　in　winter.　Thermosyphon　unit　prototypes　were　developed　and　tested　in　a　water　park.　The　relations　between　ambient　temperature,　depth,　material,　structure,　underground　temperature,　and　root　temperature　were　studied　experimentally.　The　thermosyphon　unit　performance　was　analyzed.　Results　indicate　that　underground　and　root　temperatures　remain　almost　constant　with　an　hourly　ambient　temperature.　The　root　temperature　remains　steady　due　to　the　thermosyphon　unit　application.　The　underground　temperature　increases　with　the　depth　increase,　and　the　increment　is　at　most　1　°C.　The　root　temperature　of　a　copper　thermosyphon　unit　is　higher　than　that　of　a　steel　thermosyphon　unit,　and　the　temperature　difference　can　reach　2　°C.　The　root　temperature　of　a　type　I　thermosyphon　unit　is　higher　than　that　of　a　type　II,　and　the　temperature　increase　is　less　than　1　°C.　The　root　temperature　variation　due　to　the　thermosyphon　material　is　smaller　with　the　increase　in　depth.　©　2016　Wiley　Periodicals,　Inc.