This study was conducted to evaluate the effects of the integrated application of chemical fertilizer, vermicompost, and biochar on drought stress tolerance in Iranian borage (Echium amoenum). The experiment was arranged as a factorial design based on a completely randomized design (CRD) with three replications. Experimental treatments consisted of three drought stress levels (90, 75, and 50% of field capacity) and three fertilization regimes: 100% chemical fertilizer (90 kg NPK ha⁻¹), 50% chemical fertilizer (45 kg NPK ha⁻¹) + vermicompost (25 g pot⁻¹; 0.625% w/w), and 50% chemical fertilizer + vermicompost + biochar (80 g pot⁻¹; 2% w/w). The results showed that soil amendments markedly improved the growth and physiological responses of E. amoenum under drought stress. Under mild drought stress (75% field capacity), the application of 50% chemical fertilizer + vermicompost increased root length by 3.1-fold compared with the 100% chemical fertilizer treatment, while under moderate drought stress (50% field capacity), root length increased by 1.9-fold. Leaf area decreased by approximately 40% under moderate drought stress compared with non-stress conditions. Under moderate drought stress, the combined application of 50% chemical fertilizer + vermicompost + biochar increased carotenoid content by 1.7-fold and APX activity by 3.48-fold compared with the 100% chemical fertilizer treatment. Moreover, under moderate drought stress, MDA content in the 50% chemical fertilizer + vermicompost treatment was 55.1-fold higher than that in the 100% chemical fertilizer treatment. soluble carbohydrate content increased by 1.9-fold under mild drought stress following the application of 50% chemical fertilizer + vermicompost.