The article presents the results of comprehensive field research conducted in the conditions of the northeastern Forest-Steppe of Ukraine at the Institute of Agriculture of the Northeast of the NAAS to determine the optimal sowing parameters for modern sunflower hybrids, Slavson and Ravelin. Based on the analysis of variance, high statistical significance (p < 0.001) was established regarding the influence of sowing dates and genotypic characteristics on the formation of biometric parameters, the duration of interphase periods, and final crop productivity. It was proved that the early sowing date (April 15) ensures maximum development of vegetative mass and leaf surface area (up to 0.66 m²/plant); however, the increasing aridity of the regional climate requires an adaptive approach to selecting sowing dates to stabilize yields. Specifically, for the mid-early hybrid Ravelin, the middle and late dates (May) proved to be the most effective, with seed yields reaching 3.4–3.5 t ha-1, whereas the early-maturing hybrid Slavson demonstrated a significant decrease in productivity at late sowing to the level of 1.8–2.1 t ha-1. A comparison of the obtained results with international experience confirms that differentiated management of sowing dates, considering the maturity group of hybrids, is a crucial factor in optimizing yield structure and increasing the profitability of sunflower cultivation in the conditions of the Left-Bank Forest-Steppe.