A field experiment was carried out during two successive seasons of 2018/2019 and 2019/2020 at the Nursery of Ornamental plants, Faculty of Agriculture, Mania University. The aim of this study was to investigate impacts of compost at four levels (0, 5, 10 and 15 ton/fed) in combination with Microbein biofertilizer (M.B.) at 50 ml/plant and/or some antioxidant treatments (salicylic and ascorbic acids) on vegetative growth and flowering of Gladiolus grandiflorus var. Jester plants. Results showed that vegetative growth and flowering parameters of leaf length (cm), number of leaves/plant, leaves dry weight/plant (g), length of spike (cm), spike diameter (mm), spike fresh weight (g), number of florets/spike, lower floret diameter (cm) and lower floret fresh weight (g) were gradually increased with significant differences by increasing levels of compost. In addition, Microbein biofertilizer (M.B.) and/or some antioxidant (salicylic and ascorbic acids) treatments significantly increased all vegetative growth and flowering parameters in comparison with control treatment. Microbein biofertilizer plus salicylic acid and ascorbic acid were more effective in this concern. It was found also that the use of compost (15 ton/fed) in combination with Microbein biofertilizer plus salicylic acid plus ascorbic acid followed by 15 ton/fed with M.B. plus ascorbic acid then 10 ton/fed with M.B. plus salicylic acid plus ascorbic acid noticeably improved different vegetative growth characters and flowering parameters of gladiolus plants. As the most important characters for the quality of gladiolus, the largest length of spike (season one 65.76 cm and season two 65.76 cm), largest number of florets/spike (season one 11.65 and season two 11.98) and the highest lower floret diameter (season one 7.79 cm and season two 8.34 cm) were achieved with compost (15 ton/fed) in combination with Microbein biofertilizer plus salicylic acid plus ascorbic acid. From the results of this study, it could be concluded that adaptability of gladiolus corms of Jester variety (Gladiolus gradiflorus) to the Egyptian environmental conditions is confirmed.