Prodiamine + Isoxaben (Gemini G) is a new herbicide combination being developed by Everris dba ICL Specialty Fertilizers for pre-emergent control of grasses and broadleaf weeds on ornamental horticulture crops. The IR-4 Project completed 24 crop safety trials on 15 ornamental horticulture plant species or genera in 2017. In these trials, one species (Quercus virginiana) 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. One species (Phlox paniculata) exhibited damage sufficient to recommend growers not utilize Gemini G as an over-the-top treatment for pre-emergent weed control.