Garlic is a widely cultivated vegetable valued for its health-promoting compounds. This study investigated the effects of humic acid (HA) and potassium (K) on garlic productivity, bioactive compounds, and nutrient uptake. Afield trial was conducted to evaluate treatments combining potassium sulfate (120 and 150 kg K₂O ha⁻¹) and humic acid (10 and 20 kg ha⁻¹). Potassium and humic acid significantly enhanced garlic performance, with combined treatments producing the most potent effects. Applying humic and K significantly increased productivity. Photosynthetic pigments increased up to 22% for chlorophylls and 45.7% for carotenoids, improving photosynthesis and photoprotection. HA raised TSS by 20% and vitamin C by 32%. Potassium enhanced TSS by24%, carbohydrates by 3%, and vitamin C by 28%. Combined treatments maximized TSS (+32%) and vitamin C(+38%), with polyphenols restored to 40%. Bioactive compounds, metabolites, and antioxidants were enhanced, with proline up to 45%, H₂O₂ up to 55.7%, APX up to 25%, SOD up to 42%, and CAT up to 25–79%, indicating improved osmotic and oxidative management. Nutrient uptake (N, P, Ca, Mg, S, and K) improved markedly, highlighting balanced nutrient allocation from leaves to cloves. Moderate combinations (K120+HA10) maximized yield, improved photosynthetic pigments, increased vitamin C and total soluble solids, and balanced nutrient allocation between cloves and leaves. These results demonstrate that integrating HA and K provides a practical strategy to support sustainable production under nutrient-efficient management