Growth and Landscape Performance of Ten Herbaceous Species in Response to Saline Water Irrigation.

Ten herbaceous perennials and groundcovers were grown in raised beds from June to September in a dry, hot desert environment and micro-spray drip irrigated with synthesized saline solutions at electrical conductivity of 0.8 (tap water), 3.2, or 5.4 dS/m. Plant height and two perpendicular widths were recorded monthly to calculate the growth index. Landscape performance was assessed monthly by visual scores. Salinity did not affect the visual scores in Achillea millefolium L., Gaillardia aristata Pursh, Lantana x hybrida 'New Gold', Lonicera japonica Thunb. 'Halliana', and Rosmarinus officinalis L. 'Huntington Carpet' throughout the experiment. Glandularia canadensis (L.) Nutt. 'Homestead Purple' performed better than Glandularia x hybrida (Grönland & Rümpler) G. L. Nesom & Pruski. Lantana montevidensis (Spreng.) Brig. had lower visual scores at 5.4 dS/m compared to the control and 3.2 dS/m. Most plants of Rudbeckia hirta L. did not survive when irrigated at 3.2 dS/m or 5.4 dS/m. Shoot biomass of A. millefolium, G. aristata, L. x hybrida, L. japonica, R. officinalis, and V. macdougalii was not influenced by the salinity of irrigation water. Therefore, A. millefolium, G. aristata, L. x hybrida, L. japonica, and R. officinalis can be irrigated with non-potable water at salinity up to 5.4 dS/m with little reduction in growth and aesthetic appearance.