They look a little deficient in something, may be Nitrogen? What type of soil are you using? It looks to be a lot of compost material, although I could be wrong. If so I would next time mix your soil with 2 table spoons of dolomite lime to act as a PH buffer. I have done this and have not had problems again with PH. Even if you don't need it, it won't hurt. Just a suggestion and good luck! Oh ya, are you using any nutes?

TGT