There have been continual attempts to identify alternatives to increase the agricultural output to improve the living standards of farmers, meet the current demand, and promote sustainability in commercial agriculture. Within this paradigm, low-temperature plasma (LTP) treatments have piqued the attention of investigators and are presently being extensively researched in the agriculture sector. A preliminary study was conducted on mustard seeds (Brassica nigra) to examine the potential of LTP in agriculture to enhance germination and productivity. The seeds were subjected to LTP treatment for 1 to 4 min in an argon environment (11.7 kV, 50 Hz, and Q = 3 L/min) at atmospheric pressure. The germination and growth parameters of the untreated and treated seeds were calculated on the 16th day of the seeds’ germination and compared. All germination and growth-related parameters were found to be improved in LTP-exposed seeds up to 3 min. However, the germination and growth-related parameters deteriorated in 4-min LTP-treated seeds compared to those of control and other treatment time seeds. The water contact angle and scanning electron micrograph images clearly indicated that there is a significant change in the seed coat after being exposed to LTP for a specific time period. The treated seed’s texture was significantly rougher than that of the control, which is directly related to the hydrophilicity of seeds. The findings of this study suggest that using seeds exposed to LTP for a suitable time results in a considerable increase in the germination percentage of sown seeds while also hastening seedling growth and development.