So I'm thinking I harvested my last crop top soon. Or it could have been too late. The trochromes looked good, pistols turned, yet the leaves never yellowed, and sugar pistols/hairs never shrunk back in. It took way to Long as it was, and went far over its scheuled flower time. Then again it was an 80% sativa and I grew it under cfl's (even though I used 3 actual 100w cfl's and 3 supplemental 100w equiv cfl's) I'm switching over to an hps as soon as I have the help to swap out my current light bank with the new one. (400w, xtrasun hood, lumatek ballast, and a HiLux Gro bulb )
I believe, could be wrong, that it just depends on the plant. I've heard countless times where the pistils didn't recede and what not. As far as the fan leaves go, I think that has to do with the amount of n ur giving ur plants. In general if it feeding them less n and more k then yea the leaves will tend to fall off and turn yellow. This is where that whole plant harvest time debate comes into play, some say to harvest when tricomes are milky because it's at it's highest potency then, others like it better when it turns slightly amber, other don't even go off of tris, it's all preference. I personally would rather wait a little longer and have the buds fatten up way more and Lose a little potency.
No, they don't always yellow and fall off. It is strain dependent to some degree. Some plants, like some Haze plants, drop all their leaves early in flowering and continue to develop huge buds. Others hold onto their leaves like their balls and keep them green despite watering with nothing but RO for the last month of flowering. With most strains, they should yellow and die, but there are always those that don't play by the rules. Knowing when to harvest comes with experience. Plain and simple. The more you see, the more you'll know. Overall plant appearance, Pistil maturity, Trichome maturity, and Time spent in flower are all parameters that people use to judge when to harvest. That has been my experience anyhow. I know it is only 10X and everyone says you need 30X-60X to see Trichomes well. Quality 10X will outperform shit 30X, 60X, and 100X all day long. Trust me, I own them all. This is what you want for checking trichomes: Zeiss D40 10x Pocket Loupe Magnifier That is a good deal unless they bust you in the shipping. I paid $100 for mine on Amazon. I love it. I can take a picture of all the other scopes I have so you can at least know to avoid those ones if you choose not to take my advice and get the Zeiss. When it comes to optics, it is all about quality, and that is reflected in the price. I use it so often, I wear mine on a gold chain at all times. Functional jewelry. EDIT: Those new USB scopes can be very nice for viewing trichomes too. I don't know the price range on those, as I don't own one yet. I do own a nice bench top stereoscopic scope for viewing buds, but that doesn't work when the buds are still connected to the plant. A good Bench Top Scope is definitely a good thing to have in the bud game as well.