A field experiment was carried out to study the effect of mulching and potassium application method on growth and yield parameters of potato at Rolpa, Nepal from February, 2022 to July, 2022. The experiment was laid out in 2 factorial Randomized Complete Block Design (RCBD) with three replications consisting of 8 treatments. The variety used was Rolpa local. First treatment factor consisted of three mulching materials namely silver on black plastic, black plastic and plant residue including control plot whereas second treatment factor consist of two method of potassium application: split application and basal application of recommended dose. Days to 90% germination, plant height, number of leaves, and canopy diameter exhibited significant variations among the various mulching materials, while the method of potassium application showed no notable impact on these parameters. Notably, plastic mulches played a significant role in the germination rate, with potatoes sprouting 5-6 days earlier than the control group. However, all subsequent observations related to growth and yield parameters demonstrated significantly superior results in the case of silver on black plastic mulch. The silver on black plastic mulches, in particular, displayed a substantial influence, resulting in the highest tuber number, tuber weight, and tuber yield at 23.12, 62.16 gm, and 24.09 t/ha, respectively. Additionally, remarkable tuber characteristics, including circumference, diameter, and length, were recorded with silver on black plastic (14.20 cm, 4.74 cm, and 5.40 cm, respectively). Moreover, variations in tuber weight and total yield were observed among different potassium application methods, with the split application of potash yielding the highest total of 19.66 t/ha. The split application of potassium also produced the highest circumference (13.06 cm) and tuber diameter (4.07 cm), accompanied by a superior benefit-cost ratio of 2.65. Noteworthy was the highest benefit-cost ratio of 2.92 achieved with silver on black plastic mulch. Despite exploring the interaction effect between these two factors for both growth and yield parameters, no significant findings were observed. Consequently, it was concluded that silver on black plastic mulch combined with the split application method of potassium proved to be more effective for promoting growth and tuber yield, exhibiting a promising benefit-cost ratio