The quantification of ecological services from green roofs in Texas is emergent and proving advantageous. Identification of candidate plant species for green roofs in Texas and similar hot and humid subtropical climates is limited. Three extensive green roof systems and research sites in Texas employed different water conserving techniques ranging from no irrigation, to sparse application during dry and drought periods, to frequent watering with harvested rainwater. Thirty-four candidate species were identified for hot and humid climates from among the three sites. These findings help to establish a reference point for future investigations of green roof plant survivability.