Jerusalem artichoke (Helianthus tuberosus L.) is a plant with high yield potential. Biostimulants can increase the quality and quantity of the raw material obtained. The aim of this study was to evaluate the effects of the application of four biostimulants on the relationship between plant height, chlorophyll content (SPAD index), and yield of Jerusalem artichoke plants. The field study was conducted for three years in a split-plot design with three replicates. The first factor considered was two cultivars of Jerusalem artichoke (Albik and Rubik), while the second factor was the biostimulant application variants (B1, B2, B3, B4) and the control variant (C). The biostimulant variants used in the experiment increased chlorophyll content (by 5.6%), plant height (by 6.8%), and total yield (by 28.7%) compared to the control variant. In addition, the mean values of plant height and SPAD indices showed significant positive correlations with tuber yield at all time points, highlighting the importance of morphological and physiological traits for yield prediction. The investigated traits varied depending on cultivar and crop year, indicating the need for further research.