Reuse of treated wastewater is vital to increase green cover and bio-product and minimize environmental degradation. Seven tree species were planted and irrigated with borewell water at 1/2ET (Evapotranspiration, I-1) and treated wastewater at 1/2 ET (I-2), 3/4 ET (I-3), and 1ET (I-4) to assess growth, productivity and efficient species in utilizing wastewater for more biomass. Wastewater was saline with high Na and low NH4-N, NO3-N and PO4-P. Irrigation from I-2 to I-4 enhanced (P < 0.05) height (6.7-11.1%), collar diameter (9.0-17.6%), crown diameter (14.7-20.8%) and total biomass (41.2-87.3%) over borewell water plants (I-1). Increases in biomasses were greater in shoot (stem, branches and leaves) than roots reducing root-shoot ratio with plant age. Varying irrigation levels had no effects on shift in biomass allocation between components, but impact of species was significant with highest biomass allocation to stem in E. camaldulensis and A. indica, and branches in other species. Mean Annual Increments (MAIs) in growth and biomass were less in P. cineraria/T. aphylla, medium in Salvadora oleoides, E. camaldulensis and S. persica, and highest in A. indica and P. juliflora. Conclusively, indigenous P. cineraria, S. oleoides and S. persica along with T. aphylla tended to adapt wastewater irrigation by allocating greater biomass to roots. E. camaldulensis, A. indica and P. juliflora maximized root biomass to sustain above-ground productivity. S. persica, A. indica and P. juliflora were most efficient in utilizing treated wastewater and can be beneficially reused in afforestation, producing biomass for people and environmental amelioration in arid areas.