Water scarcity in arid and semi-arid regions such as Jordan poses a critical challenge for sustainable land use and agricultural productivity, necessitating optimized irrigation strategies for drought-tolerant species. This study was conducted to evaluate the effects of irrigation schedules on growth, fruit yield, water use efficiency, and proximate composition of four Ziziphus species (Ziziphus mauritiana, Z. spina-christi, Z. jujuba, and Z. lotus) under field conditions in the Jordan Valley. A split-plot design was used, with the main plot being the irrigation treatment and the subplots being the four Ziziphus species, with four replications over five growing seasons (2015-2019). The results show significant variation in plant height (p < 0.001) and stem diameter (p < 0.001) between the Ziziphus species. The results indicated that Z. mauritiana Lam. had the highest yield and water use efficiency (15.15 kg/m3) under weekly irrigation. Proximate analysis of leaves and seeds revealed that leaf protein content was approximately twice that of seeds across all species, with Z. jujuba and Z. spina-christi exhibiting the highest leaf protein content. These findings demonstrate that Z. mauritiana and Z. spina-christi are the most productive and water-efficient species under reduced irrigation frequency, and support their adoption in water-limited agroforestry, dryland afforestation, and land restoration programs for farmers cultivating Ziziphus in Jordan's arid and semi-arid zones.