Zakat for residential plots

I have already having 2 residential houses and 1 commercial property for which, i am paying zakat on the rental income. I have purchased 8 residential plots at different durations ranging from year 2000 to 2009. The intention of keeping these residential plots for my daughter’s studies and for their marriage. After my children marriage, if i have plots, i will gift my children accordingly. Please advice, i have to pay for these 8 residential plots.