Secondary effects of strobilurin applications may improve creeping bentgrass tolerance to high temperature stress. This research evaluated the effects of two strobilurin fungicides on the rooting of ‘Penncross’ and ‘Penn A‐1’ creeping bentgrass (Agrostis stolonifera L.) managed under two irrigation regimes during high temperature conditions in a greenhouse. The light and frequent (LF) regime irrigated to 100% evapotranspiration daily, and the deep and infrequent (DI) regime irrigated at leaf wilt to a 30 cm depth. Plants were maintained in a greenhouse that averaged a maximum daily temperature of 31°C. Fungicide treatments were pyraclostrobin (556 g a.i. ha−1), pyraclostrobin + boscalid (431 + 288 g a.i. ha−1), azoxystrobin (610 g a.i. ha−1), and a nontreated control. Azoxystrobin reduced visual root length and root biomass of Penncross plants compared to nontreated plants. Root length, root length density, and root biomass of azoxystrobin‐treated Penn A‐1 plants were also lower than nontreated plants under LF irrigation. Pyraclostrobin increased the visual root length of both cultivars under DI irrigation, and resulted in Penn A‐1 plants exhibiting increased total root length, root surface area, root length density, root volume, and root biomass compared to nontreated plants. Changes in rooting were not associated with changes in turfgrass quality for either cultivar. Additional research is needed to determine if these responses are present following applications in the field.