We examined the effect of source, concentration, and application method of silicon (Si) on the growth, development, and photosynthetic capacity of Fragaria × ananassa ‘Maehyang’ and ‘Seolhyang’. We applied 0, 35, or 70 mg L−1 Si in a potassium silicate (K2SiO3), sodium silicate (Na2SiO3), or calcium silicate (CaSiO3) solution to plants via subirrigational supply or foliar application. Plant height of ‘Maehyang’ was highest with the 70 mg L−1 Si Na2SiO3 foliar application, but it was not significantly different among treatments in ‘Seolhyang’. Crown size was not significantly affected by source, concentration, or application method in both cultivars. Elemental concentrations in the shoot and root of ‘Maehyang’ were the highest in the 35 mg L−1 Si Na2SiO3 treatment for both application methods. Elemental concentrations in the shoot and root of ‘Seolhyang’ were the highest in the 70 mg L−1 Si K2SiO3 foliar application. Photosynthetic proteins abundantly increased in both cultivars with the 35 or 70 mg L−1 Si K2SiO3 treatment, for both application methods. Moreover, two important photosynthetic proteins, viz. PsaA and PsbA, were expressed and their expressions were higher with the 35 or 70 mg L−1 Si K2SiO3 treatment, for both application methods. These results suggested that 35 or 70 mg L−1 Si, supplied in the form of K2SiO3, promoted photosynthetic protein expressions the greatest, regardless of the application method, in both ‘Maehyang’ and ‘Seolhyang’. © 2018, Korean Society for Horticultural Science and Springer-Verlag GmbH Germany, part of Springer Nature.