No haven't given them any fert yet. They were given to me by a friend to grow for him and he had them growing in a dirt/clay ish type soil which i believe is the cause for their stunted growth. I think they shoudl take off now that i have replanted them in miracle grow potting soil. When should I start to fert, how much/often and what type should i use? Thanks for the help. I hope they'll be taking off once their roots take to the new soil and out of the old dirt....
p.s. They may be younger than 2 1/2 weeks too, I can't be 100% sure.

In addition, I am pretty sure that their slow growth was due to their original growing medium. I have another plant not pictured that is only at about 1 1/2 weeks which is already the same size as the ones photographed.