Caisim (Brassica rapa L.) is a horticultural commodity that plays an important role in supporting the Indonesian economy. To increase plant growth and yield, the use of fertilizer is essential. However, excessive dependence on chemical fertilizers can damage soil structure and fertility. One environmentally friendly alternative is the use of liquid organic fertilizer (POC) from agricultural waste materials, such as banana stumps, which are known to contain important nutrients such as nitrogen (N), phosphorus (P), and potassium (K). This study aims to determine the effect of applying POC from banana stumps on caisim plant yield and to determine the best concentration that can provide optimal results. The study was conducted for three months, from January to March 2025, at the Paslaten 2 plantation, East Tomohon District, Tomohon City, using a Completely Randomized Design (CRD) with six treatments and five replications. Data were analyzed using analysis of variance (ANOVA) and continued with a 5% LSD test if there was a significant effect. Observed variables included plant height, number of leaves, and plant fresh weight. The results of the study showed that liquid organic fertilizer from banana stems had a significant effect on the number of leaves and fresh weight, but not on plant height. Keywords : Caisim; Brassica rapa L.; Banana stump; Liquid organic fertilizer; Plant growth and yield.