This study explored the effect of gaseous enrichment of vase solution, in combination with ethylene inhibitors and bioactive chemical treatments, on vase life and antioxidant defense of Matthiola incana cv. ‘Lucinda’ cut flowers. Postharvest senescence and rapid quality loss remain critical limitations in commercial floral supply chains. A completely randomized factorial experiment was conducted including 20 treatment combinations, with three replicates per treatment and three stems per replicate (total 180 stems). Treatments consisted of gaseous signaling molecules (50 µM nitric oxide and 1% hydrogen gas) applied to vase solution, ethylene inhibitors (1-MCP and KMnO₄), and chemical solutions (distilled water; chitosan + CaCl₂; chitosan + SNP; chitosan + arginine; chitosan + STS). Evaluated traits included vase life, solution uptake, petal anthocyanin content, leaf carbohydrate concentration, antioxidant enzyme activity (CAT and POD), ion leakage, and stem water content. The combined treatment of nitric oxide, 1-MCP, and chitosan + SNP (G₁E₁C) produced the longest vase life (25.3 days), improved solution uptake, enhanced anthocyanin and carbohydrate accumulation, and effectively delayed senescence. Statistical analysis confirmed significant effects of gas enrichment, ethylene inhibitors, chemical treatments, and their interactions on most physiological traits (p < 0.05). Pearson correlation analysis indicated strong positive relationships between vase life and physiological indices. These results demonstrate that gaseous enrichment of vase solution, combined with ethylene inhibition and bioactive compounds, mitigates oxidative stress, preserves membrane integrity, and significantly extends vase life. This approach provides a promising and practical postharvest strategy for commercial cut flower management.