Four wild medicinal and aromatic plants were studied for their allelopathic potential against Convolvulus arvensis. The wild plants were collected from different elevation zones of Quetta, Balochistan. Two species of genus Sophora viz. Sophora mollis (Royel) Baker. and S. alopecuroides L. were collected from Sra Ghurgai (Takatu mountain Range) and University of Balochistan Quetta campus, respectively. While Perovskia abrotanoides Karel. was collected from SraGhurgai and Zarghoon region of different elevation zones and Peganum harmala L. was collected from SraGhurgai (Takatu Mountain Range) and University of Balochistan Quetta Campus. Phytotoxic effect of the four plants was studied at various grades of aqueous extracts i.e 4 and 32% (w/v). To check germination impact and seedling growth of weed C. arvensis L. water-soluble phenolic content and its impact as inhibitory substance was also investigated along with the impact of altitudinal gradient on phenolic concentration and its effects on seed germination of C. arvensis. Water-soluble phenolic contents in the plant extracts were found. Total phenolic contents were higher i.e 0.122±0.08 in plants collected from higher altitudes which corresponded with the stronger inhibitory activity on C. arvensis. Total phenolic content was found as S. mollis>P.harmala>P.abrotanoides>S. alopecuroides. Final Germination Percentage of C. arvensis revealed that all tested wild plants leaf aqueous extracts significantly suppressed seed germination. Root and shoot length indicated that increased concentration of all plants extract showed significant reduction of C. arvensis Root and Shoot length. Our results revealed that these wild plants could prove as natural herbicide to control weeds like C. arvensis or serve as a template for synthetic herbicides.