The quality and quantity of lily cut flowers depend mostly on the composition of growing media. To evaluate the effect of two sources of the palm peat substrate (the palm trunk: Prepared from the trunk of the date palm; the palm tree: Prepared from all parts of the date palm) on plant growth traits related to cut lily flower, a factorial experiment arranged in a completely randomized design with three replications. The impact of eleven root growing media consisted of mixtures of palm peat, cocopeat, and perlite on two cultivars (‘Tiber’ and ‘Candy Club’) were evaluated under hydroponic conditions. The results showed that the stem diameter, the time of flower emergence, buds length, leaves relative water content (LRWC), leaves and petal's electrolyte leakage (LEL and PEL), bud visual quality, and quality index criteria were as more in the ‘Candy Club’, but SPAD1 and bud diameter characters were higher in the ‘Tiber’. The highest amount of chlorophyll a, b, and total, SPAD1, SPAD3, stem diameter, bud diameter, and quality index were observed in control (80% cocopeat + 20% perlite), which was not significantly different from some palm trunk, and reused cocopeat substrates. The higher value of LRWC, bud length, and carotenoid was observed in 20% palm trunk treatment, while the higher flower longevity occurred in 60% palm tree treatment. 80% reused cocopeat treatment was showed the highest number of bulblets, SPAD2, and time to harvest. The lowest amount of LEL, harvest time, and time of flower emergence was observed in the control. Various cultivars differently respond to growing media, and palm trunk and reused cocopeat could replace a part and, or whole of expensive imported cocopeat. The palm trunk substrates were superior to the palm tree substrates, but there was a low advantage of control than the palm trunk substrate. تفاصيل المقالة