The increase in the cost of traditional energy carriers and the need to diversify fuel resources encourage the search for alternative energy sources, which is critically important for Ukraine’s energy security and economic competitiveness. The utilization of the potential of bioenergy crops makes it possible to effectively involve low-productivity lands, improve the ecological condition of regions, and ensure a stable supply of renewable raw materials for the production of solid and gaseous biofuels. The article presents the results of research on the cultivation of perennial energy crops in the Western Forest-Steppe zone. The influence of mineral fertilizers and the biostimulant BlackJak on the productivity of green and dry biomass of Virginia mallow (Sida hermaphrodita), giant miscanthus (Miscanthus giganteus), and perennial sorghum (Sorghum almum) was analyzed. It was established that intensification of plant nutrition ensured an increase in dry matter yield at the level of 36.5–42.5%, which directly correlates with an increase in energy output. Special attention was paid to the calculated biogas yield, where Virginia mallow was identified as the leader with an indicator exceeding 10000 m³/ha under combined fertilization. The expediency of introducing modern growth stimulants to optimize the bioenergy potential of second-year plantations was substantiated.