Oil palm productivity is often limited by soil conditions and nutrient availability. The use of organic amendments such as biochar and palm oil mill effluent (POME) can be a solution to improve physiological properties and fruit yield. The objective of this study was to determine the interactive effect of biochar produced from empty fruit bunches (EFB) and varying POME application intervals on the vegetative growth and physiology of oil palms. A field experiment was conducted from October 2024 to July 2025 at the PT Perkebunan Nusantara IV oil palm plantation, located in Lagego Village, Burau District, East Luwu Regency, South Sulawesi, Indonesia. A two-factor factorial experiment was conducted with biochar EFB doses of 0, 1.85, 3.70, and 5.56 tons ha⁻¹, and POME applied without application, every two months, and every four months. The combined application of biochar and POME significantly increased LAI (6.15), chlorophyll content (a.b and total), and stomatal aperture (260.49 μm2) in the treatment of 5.56 tons ha⁻¹ of biochar with POME applied every four months. There were no significant differences in the number of shoots, leaf production, or stomatal density. The integration of biochar with timely POME application offers a promising strategy for sustainable oil palm management through improved physiological performance and nutrient use efficiency.