Abstract: The growth characteristics of transgenic Gladiolus plants cvs. ‘Peter Pears’ and ‘Jenny Lee’ were compared to non-transformed plants either regenerated from embryogenic callus or micropropagated in vitro. Micropropagated and regenerated plants of ‘Peter Pears’ showed similar sprouting percentage of corms in vitro and daughter corm production after one season in the greenhouse. Differences were found in the weight of corms produced in vitro and the length of leaves with the regenerated corms weighing less and having shorter leaves than those of micropropagated plants. Transgenic plants of ‘Peter Pears’ had similar corm weights to those from regenerated plants, but the greenhouse sprouting percentage, leaf length, and daughter corm production was less than that of regenerated plants. Micropropagated plants of ‘Jenny Lee’ were similar to regenerated plants in weight of corms grown in vitro, sprouting efficiencies, and the length of leaves. Transgenic plants of ‘Jenny Lee’ produced larger corms in vitro than regenerated plants, and both the final weight of transgenic corms and leaf length after one season in the greenhouse were comparable to that of regenerated plants of ‘Jenny Lee’. ‘Jenny Lee’ plants were less affected by the regeneration and transformation conditions than ‘Peter Pears’.