Grapevine is one of the most important perennial fruit crops worldwide, and it is particularly impacted by the effects of climate change. This study evaluated the commercial natural fertilizer Resonant® Fortify White in two commercial vineyards, focusing on its impact on vine growth, yield, and grape quality. The findings show that treated vines consistently exhibited enhanced vegetative growth, evidenced by significantly longer shoots (increases ranging from +11% to +50%) and reduced occurrence of blind buds along the fruiting cane. Furthermore, an increased leaf area and leaf chlorophyll content, alongside improved water stress tolerance was measured. Additionally, pruning wood amounts were higher for treated vines in both vineyards, +40% and +13%. At harvest, treated vines showed higher yield per vine, +16% in both sites, compared to untreated vines, with comparable TSS, pH, acidity and with increased YAN values (+63% and +61%). The findings of this study suggest that the application of the natural fertilizer Resonant® Fortify White may represent a sustainable solution to optimize nitrogen absorption, vine balance, and yield without compromising grape quality.