This study was carried out during 2015 and 2016 seasons to investigate the effect of different concentrations (0.05, 0.1 and 0.2%) and frequencies of application of (once, twice or thrice) potassium silicate on vegetative growth aspects and nutrients in the leaves as well as yield and fruit quality of Zaghloul date palms. Randomized complete block design was adopted. Treating the palms once, twice or thrice with potassium silicate at 0.05 to 0.2% had an announced effect on improving all growth traits, leaf chemical components, bunch weight, yield and fruit quality over the check treatment. The promotion on these parameters was in proportional to the increase in concentrations and frequencies of application. Meaningless improvement on these parameters was recorded among the higher two concentrations (0.1 & 0.2%) and frequencies of application (twice & thrice). For improving yield and fruit quality of Zaghloul date palms, it is necessary to spray the palms twice before hand pollination and again just after fruit setting with potassium silicate at 0.1%.