Hello! I work for an environmental consulting company and we have recently been hired by a client requesting a pre-development assessment of potential soil contamination and the horticultural suitability of the soils across a 22-acre property in Grand Junction, CO. In addition to testing and analyzing the soil conditions, the client requested recommendations for soil amendments to support the addition of shade trees, shrubs, ornamental grasses, and groundcover vegetation. After conducting composite soil analysis through the Colorado State University Soil, Water and Plant Laboratory, we found that the soil across the site is generally strongly alkaline, with moderately high soluble salts, high excess lime, high potassium, high calcium, high magnesium, high sulfate, high chloride, and high sulfur. I am reaching out for some guidance in both my soil amendment recommendations as well as some recommendations for plants that would tolerate such soils. I have been researching adding gypsum for remediating the salinity, sulphur for pH, biochar for microbes, and vermiculture to increase organic matter. Do you have recommendations for the rate of application for such amendments? Am I overlooking any beneficial amendments? Are there some amendments that should be prioritized over others? The project site is in the plant hardiness zone 6b. Some plants I am considering recommending are Blue-beak yucca (Yucca rostrata), Common stonecrop (Sedum sediforme), Hens-and-chicks (Sempervivum spp.), Parry's agave (Agave parryi), Prairie coneflower (Ratibida columnifera), Dream of Beauty aster (Symphyotrichum oblongifolium ‘Dream of Beauty’), Meadow sage (Salvia nemorosa), Butterfly weed (Asclepias tuberosa), Blanket flower (Gaillardia), Russian sage (Perovskia atriplicifolia), Columbine (Aquilegia), Catmint (Nepeta), Creeping Thyme (Thymus serpyllum), Coneflower (Echinacea Purpurea), and Common yarrow (Achillea millefolium). Do you have recommendations for some shade trees and shrubs that I could add to my list? Let me know if it would be helpful to see the soil data that we received from Colorado State University Soil, Water and Plant Laboratory. Thank you so much for your time! -Kori