This is the first year I've ever grown my own dill. I want to make pickles, and don't know when I should pick the dill heads. Right now, I have one that is just starting to form yellow flowers, another one that that has little green "bumps/balls" (just before the yellow flower stage) and I have some more that are just starting to form heads (they have the little green "bumps" or "balls," just very compact and not having spread out into the "firework" like shape). When do I pick these to get the best flavor for dill pickles?