Reduced-growth, glyphosate-resistant Kentucky bluegrass (Poa pratensis L.) has recently been developed. There has been no comparative analysis of the newly developed transgenic Kentucky bluegrass lines to reference cultivars or tissue culture control lines to determine vegetative and floral characteristic differences and similarities. This study measured the vegetative and reproductive characteristics of the transgenic lines, tissue culture control lines, and reference cultivars during 2004 and 2005, in Ames, IA. The study was conducted in a noncompetitive, nonmown, spaced plant setting. Data collection of vegetative characteristics included rhizome proliferation and total plant area. Data collection for floral characteristics included flower phenology, reproductive structure measurements, and morphological characteristic measurements, including panicle length, number of spikelets per panicle, and flag leaf characteristics. Transgenic lines as a group exhibited 29 and 32% less rhizome spread than the reference cultivars and tissue culture control lines, respectively, in 2004 and 37 and 40% less rhizome spread than reference cultivars and tissue culture control lines, respectively, in 2005. Transgenic lines as a group exhibited 45 and 47% less colony area than reference cultivars and tissue culture control, respectively, in 2004, while they exhibited 55 and 57% less colony area than reference cultivars and tissue culture control lines, respectively, in 2005. Flower emergence times for all transgenic lines were comparable to their respective tissue culture control lines and reference cultivars. Anthesis duration for all transgenic lines was either similar or shorter than their respective tissue culture lines and reference cultivars. Transgenic line Tx01-2900 showed the most promise for potential commercial release, while Bx01-5609 showed the least.