Prodiamine + Isoxaben (Gemini G) is a herbicide combination developed by ICL Specialty Fertilizers for pre-emergent control of grasses and broadleaf weeds on environmental horticulture crops. The IR-4 Project completed 85 crop safety trials on 29 environmental horticulture plant species or genera between 2017 and 2023. In these trials, five species (Campanula sp., Euonymus alatus, Nepeta x fassiana, Quercus virginiana, Rosa sp.) exhibited no injury after over-the-top applications in a minimum of 3 trials; E. alatus and N. fassiana can be added to a list of tolerant plants in the new label for this product. Three species (Phlox paniculata, Sedum acre, Sedum rupestre) exhibited damage at the 1X rate sufficient to recommend growers not utilize Gemini G as an over-the-top treatment for pre-emergent weed control.