i had left a recent strain of mine in 12/12 for around 18 weeks, due to the fact i found out that we had no clones, so in last resort i harvested that buds i had left on there, cutting around them to ensure leaves stayed. (no leaves= no photosynthesis ) but what was amazing to me was around 15 or 16 weeks about 2 weeks after a top of the plant harvest (leaving less than 1/3 of total buds on), new growth appears.
The new growth looks like over sized "foxtails" bright green, almost more lushes that when the original buds grew but never any male reproductive parts appear all the way until 18 or 19 weeks, the 1/3 was then harvested since the new growth appeared leaving all the leaves i could, is now back in 18/6 to hopefully reveg. this would be my first attempt at it and it is the longest plant to be under 12/12 in my 10 harvesting experiences.
The 1/3 that was left after 18 or 19 weeks was cured for about 20 days not including 5 days to dry to about 20% moisture. It was much different that the first 2/3 by many more ambers, and some very dark ambers, (60-100x) because of around the 2/3 harvesting date 12-13weeks in the trics were about 75%-20%-5% Cloudy-amber-clear. so in and extra 5-6 weeks it went to about 20%-60%-15%-5% Cloudy, solid/moderate amber color, dark/very dark amber color, clears or maybe cloudy. It was very nice to smoke, i only actually noticed a slighty moderate change to the way it smoked, but it had a slightly shorter cure than usual. As for the trichs being more ambers than not and with the extra dark ambers, it made the perfect sleep-time cure, nice body buzz and pretty powerful. I usually like to get a decent mixture with cloudy always dominant But its always up to the grower when He/She Harvests, i just personally like getting mind-blowed instead of couch-locked,
FlithyFletch Has it right on too. Hope this helps, you got some pretty sketchy comments so far