Abstract: An improvement to sprinkler heads used in tree orchards and the like wherein it is undesirable to have irrigation water maintaining the trunks of the trees in a constantly wet state. The sprinkler heads involved are the vertically disposed cylindrical type wherein a rotating nozzle at the top thereof creates a horizontal spray pattern. The improvement comprises a cylindrical collar for mounting on the sprinkle head body with at least one vertically dispoed wedge-shaped fin mounted thereon. By placing the fin radially between the nozzle opening of the sprinkler head and the tree trunk the wedge-shaped fin splits the stream which would otherwise strike the tree trunk and causes it to pass on either side of the tree trunk. Various embodiments are shown to provide adjustability of the fins position and a plurality of fins on one sprinkler head.