Prodiamine + Isoxaben (Gemini G) is a herbicide combination developed by Everris dba ICL Specialty Fertilizers for pre-emergent control of grasses and broadleaf weeds on environmental horticulture crops. The IR-4 Project completed 65 crop safety trials on 23 environmental horticulture plant species or genera between 2017 and 2022. In these trials, four species (Campanula sp., Nepeta x fassiana, Quercus virginiana, Rosa sp.) exhibited no injury after over-the-top applications in a minimum of 3 trials; this species 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.