I didn't watch mine that close, but they say thinner pieces start faster, but grow slower. Thicker start slow and then take off fast. Makes sense cause they have more to feed of. Did you cut those big ones up and spread out? Like how many (potential) plants did you get out of it?
i cut them in about 3-4 inch pieces. planted them along a 18 ft row. i don't recall how many potential plants i got out of it, filled the row up though.