Fiesta (Iron HEDTA) is a new herbicide currently labeled for post emergence broadleaf weed control on lawns (use on rights of way or non-crop areas), turf, golf courses, parks, playgrounds, cemeteries and athletic fields. Neudorff is interested in adding environmental horticulture crops to their label. The IR-4 Project completed 166 crop safety trials on 83 environmental horticulture plant species or genera during 2016 to 2021. In these trials, Fiesta (Iron HEDTA) exhibited no or minimal negative impact on 7 plant species / genera (Buxus sp., Calamagrostis acutiflora, Carex cherokeensis, Festuca glauca, Juniperus spp., Muhlenbergia capillaris and Taxus x media) when applied to either dormant or actively growing plants. Eight species / genera (Cotoneaster apiculatus, Cotonieaster sp., Heuchera spp., Hemerocallis sp. Hibiscus sp., Lagerstroemia indica, Ophiopogon sp. and Teucrium chamaedrys), where Fiesta was applied to actively growing plants, exhibited no phytotoxicity at 1X but did have some injury at 2X and 4X rates. Twenty-one species / genera exhibited significant phytotoxicity at even the lowest rate such that it is recommend that growers not use Fiesta (Iron HEDTA); in ten of these crops, Fiesta was applied to dormant plants. For 46 genera / species, more information is needed either because only 1 or 2 trials were conducted or because consistent results were not achieved across research sites.