This article presents the results of research of studying the effect of mineral fertilizers on soil moisture and the growth and development of forest seedlings when creating forest crops on the western slope of the Western Tien-Shan. It was established by experience that forest seedlings react differently to the action of mineral fertilizers. In pine, an increase in the fertilizer dose contributes to an increase in the growth of seedlings in height by 1.2 times. English oak, on the contrary, reacts weakly to the effects of fertilizers. Korolkov’s hawthorn reacts intensively to the effects of fertilizers. At the same time, an increased dose of fertilizers contributes to an increase in the annual growth of plants by 3.2 times. The Sievers apple tree differed from other species with intensive growth in all variants of the experiment on the western slopes during the growing season. But in this breed, an increase in the dose of fertilizers caused an increase in annual growth up to 1.5 times compared with the control variant. Mineral fertilizers do not contribute to significant moisture retention in the upper soil layer during the summer vegetation season, but in the lower root-inhabited layers of fertilizer, it has a positive effect in increasing soil moisture above the wilting moisture, which is 8%, and is often observed in the upper horizons.