Technical Abstract: An ideal species for restoration in rangelands of the U.S. Intermountain West would tolerate drought and also grow rapidly to successfully compete with invasive winter annuals. However, a trade-off between stress tolerance and high growth rate would complicate the choice of plant material for restoration. We conducted a greenhouse experiment to compare the performance of Pseudoroegneria spicata and Elymus wawawaiensis, two closely related perennial, C-3 Triticeae bunchgrasses native to the Intermountain West, USA, under high, medium, and low watering frequencies. We predicted that E. wawawaiensis would have a higher relative growth rate and higher SLA than P. spicata, while P. spicata would be more drought tolerant. We also expected lower shoot biomass, higher stomatal conductance (SC), lower water use efficiency (WUE) under drought, and higher specific root length (SRL) in E. wawawaiensis compared to P. spicata resulting from a trade-off. Relative to high watering frequency, low watering frequency significantly decreased total (64.1%), shoot (63.2%), and root (71.47%) biomass across species. Elymus wawawaiensis had 27.1% greater shoot biomass, 44.4% greater SLA, 8.1% higher R/S, and 14.5% greater WUE than P. spicata across watering frequencies. Compared to P. spicata, E. wawawaiensis had greater biomass at all watering frequencies and a more favorable physiological response to drought at low watering frequency. These results show no evidence of a trade-off between drought and growth responses between the two species; E. wawawaiensis has greater potential both to maintain high growth rate under non-limiting conditions and to tolerate drought under limiting conditions relative to P. spicata.