As of this morning, a couple lower leaves have begun turning yellow as nitrogen is sucked from them - does this mean I'm getting close? I still haven't found a picture of mature pollen sacks or any written description, more and more are forming each day and continuing to swell, but I am wondering what exactly they look like when they are ready to burst.

I've seen many forum posts in which someone says that they found a male that looked like it was just about ready to release pollen - unfortunately there are no pictures, and they don't describe what exactly this 'almost ready' point looks like.

I guess I could just wait and check daily until the first sacks begin to split open and then isolate the plant so that I can do a more controlled collection from that point. Does anyone know if they will change color as they mature or will they still be light green?

In the mean time, I have shut off my circulating fan to avoid spreading pollen at random, leaving just the exhaust fan running as I want to do a controlled pollination of a couple of buds. I know that the males should finish earlier than the females so that there can be enough time for seeds to mature after pollination, but I don't know at this point just how much earlier.