Plants require a variety of elements to grow. Of these, calcium and magnesium play an important role in strengthening the cell wall. Although peaches (Prunus Persica) are highly preferred by consumers, they ripen quickly and become soft over a relatively short period of time after harvesting, making them difficult to transport and store. In addition, the ripening process of peaches proceeds very quickly. In addition, cell walls are weakened during maturation, and various pathogens can easily grow, causing rapid decay. Therefore, yield loss occurs during long-term storage or transport. To increase the storage period, a method to delay softening action is required. One potential means to improve firmness is improve calcium and magnesium content as these elements make up and strengthen cell walls. However, calcium and magnesium are not readily absorbed by plants. In this study, the size of calcium and magnesium particles were reduced to less than 900 nm via grinding and their absorption rates were evaluated in the leaves of peach trees. When plant nutrients with a small particle size by nanotechnology were sprayed on peach trees, the content of calcium and magnesium was increased in the petioles, adaxial, abaxial, and leaf side. Therefore, a reduction in the particle size of calcium and magnesium increases the absorption rate in peach leaves.