The effects of climate, soil, management, fertilization, rootstocks, and cultivars on calcium concentration in the leaves were investigated in long term experiments in southern, central or eastern Poland. The concentration of Ca in the leaves of apple trees on heavier soil with higher rainfall was higher than on sandy soil and dry climate. McIntosh/M 11 showed a higher level of Ca in the leaves than on Antonovka seedlings, while in the cv. Schatenmorelle sour cherry the effect of rootstock was negligible. There was a definite influence of cultivar in the same fertilizer treatments on Ca accumulation in the leaves. Cultivar Bancroft always showed the lowest level of Ca in comparison with Mclntosh and Jonathan. Higher doses of fertilizers usually lowered the level of Ca in the leaves of younger apple trees (Nowa Wies), but not in the old trees (Dabrowice). The accumulation of Ca in the leaves of apple trees was not affected by the type of orchard soil management, clean cultivation, or sod.