In forage shrubs, leaf production varies throughout the year regarding forage availability. Seasonal variations in leaf emergence rate (LAR), leaf senescence rate (LSR), leaf final size (LA) and leaf surface per stem (TLA) have been studied in the field in Medicago arborea (MA) and Medicago citrina (MC) plants, under irrigation and drought conditions. Under irrigation, MC plants showed significantly higher values than MA plants regarding LA and TLA. Leaf production was similar in both species and lower in winter. In spring, leaf production was high in MC plants. Under drought conditions, MC plants showed higher values of LAR than MA plants at the beginning of spring and at the end of autumn, and of TLA at the beginning of spring. MA plants had high senescence values from January onwards and during spring.