This crop develops well on spring and autumn with optimal temperatures between 15-20 °C. Prolonged low temperature, long days or environmental stresses will induce premature flowering. Well drained loam soils are ideal for adequate rooting. Optimal soil pH is 6.5 to 6.8, and liming may be needed if the pH is lower. Endive requires high levels of potassium, at a rate 2.5-fold higher than nitrogen.