This study evaluated the influence of foliar applications of seaweed extract, fulvic acid, and chitosan on the vegetative growth characteristics of F₁ hybrid pepper Capsicum annuum L. “Biskra" over two growing seasons. The experimental design consisted of eleven treatments, including individual applications of each substance and combinations thereof. Treatments T1 and T2 utilized seaweed extract, T3 and T4 used fulvic acid, and T5 and T6 employed chitosan at concentrations of 0.3% and 0.4%, respectively. Additionally, T7 through T10 involved combinations of these substances. T7 (T1+ T3+ T6), T8 (T1+ T4 + T6), T9 (T2 + T3 + T5); T10 (T2 + T4 + T6). Tap water served as the control treatment. The results showed that the combination of 0.4% concentration for each of seaweed, fulvic acid, and chitosan extract (T10) enhanced (P<0.05) vegetative growth parameters, such as plant height, number of branches per plant, and both fresh and dry biomass, leaves number, chlorophyll content and the index of leaf area. Notably, T10, along with treatments T3 (0.3% fulvic acid) and T4 (0.4% fulvic acid), produced the tallest plants and the highest number of branches per plant, with plant heights approaching 47 cm. Treatments with chitosan (0.3%) and seaweed (0.4%) also resulted in greater plant height and number of branchs with increment by 9.1 and 6.2% for chitosan as well as 5.6 and 14.1% for seaweed, respectively compared to the control. In terms of biomass, T10 exhibited superior performance, achieving dry weights of approximately 27 g and fresh weights of around 63 g, while the control treatment consistently demonstrated the lowest growth metrics. In conclusion, this study revealed that combining seaweed extract, fulvic acid, and chitosan (T10) as foliar sprays significantly boosted pepper plant growth, i.e., increasing height, branching, and biomass compared to other treatments.