The high cost of hybrid seeds and seedlings is one of the key problems faced by famers. Problems in percent germination and germination time make it uneasy for farmers to attain uniform crop establishment and timely harvest. Seed viability decreases over time, and the natural ability in plants for inducing germination weakens with prolonged storage and dormancy. However, the use of plant growth regulators such as the synthetic gibberellic acid (GA) could be an alternative for enhancing germination of expired and long stored seeds. Thus, this experiment aims to test effect of synthetic gibberellic acid (GA) in enhancing germination of expired and unexpired mustard green (Brasicca juncea) seeds. The experiment was laid out in a complete randomized design with four treatments and four replications. Result of the study revealed that applying 900ppm synthetic gibberellic acid (GA) significantly repair expired seeds and improve germination percentage from 64% to 98% (34% enhancement rate) within 80 hours. For unexpired seeds, GA could be used to achieve maximum germination of 100% within 60 hours.