Improving the quality of oriental Lilium is a big demand from farmers and florists in Egypt using proper fertilization. In this research, we studied different responses of four cultivars of oriental Lilium, ‘Bacardi®', ‘Zambesi®', ‘Adelante®', and ‘Vonq®', to six treatments of two potassium sources, potassium silicate (PS), and potassium gel (PG) with or without foliar application of Nofaterin® (Nofat.) as a source of the integral fertilizer. The results showed that the treatment PS + Nofat. produced the highest values for vegetative, flowering, and bulb growth parameters, and chemical composition like mineral contents, chlorophyll, and carbohydrate compared to the other treatments. This treatment increased leaf fresh weight, leaf dry weight, stem fresh weight, and stem dry weight at the rate of 56.92, 57.72, 61.96, 71.73%, respectively. For flowering growth, flower diameter (cm), flower fresh weight (g), and flower dry weight (g) recorded 22.95, 23.11, respectively. Nitrogen, phosphorus and potassium contents also increased as a result of PS + Nofat. treatment which recorded 4.01, 0.67, and 3.11 g/100 g D. wt, respectively. Worthy to note that potassium gel treatments did not show a notable increase in growth parameter and chemical composition. The comparison among all studied cultivars showed that Lilium cvs. Adelante and Vonq gave the best results for all growth parameters and chemical composition whereas Lilium cvs. Zambesi and Bacardi showed the lowest values. We concluded that potassium fertilization using potassium silicate with Nofaterin foliar application is recommended for oriental Lilium cultivars, but more investigations should be performed to improve Lilium cvs. Bacardi and Zambesi, as the response to our treatments indicated that it depends on the cultivars and genotypes. Our findings present successful response to potassium fertilizer in Lilium grown in Egypt opening a gate to increase commercial cut flowers by fertilizer application.