Carob, Ceratonia siliqua L., is a typical Mediterranean forest tree. In Morocco, it is used as protection against soil erosion and animals eat its fruit. The objective is to study the effect of irrigation on the survival and growth of seedlings of carob. Two water regimes (irrigation and water stress) were evaluated with 42 plants for over four periods: just after planting, then at the end of each year for three consecutive years. The study shows that the additional water supply resulted in survival rates (after a year of growth) higher than for the situation under water stress, but these differences are not statistically significant, at least until the end of the third year after planting. These survival rates were 88% in irrigated against 76% under water stress. In contrast, the study shows that irrigation has a significant effect, P-value between 1 % and 3 %, on the
growth of seedlings of carob, namely their height. Initially, there was no significant difference between the two treatments, but this difference arose and becomes significant at the end of the first year and will continued over the next two years. The mean difference (irrigated-dry) increased by 7 cm at the end of the first year, 15 cm at the end of the second year to 19 cm at the end of the third year. It can be concluded that the addition of extra water has no significant effect on the survival rate, but it has a clearly significant effect on plant growth (height). Therefore, irrigation during the first two years twice a month would be highly recommended for better growth of the carob tree.