Ah, you already posted, Doc - good. I've been composing a post before I saw yours ...
I've been running the kit for several months now, getting into third run territory with my soil. I do individual plants and strains - 17 harvests so far - and each one has different requirements for each feed/watering. I haven't done the sort of experimentation that Doc and Curso have, but I've begun to get an understanding about how the pieces of the kit work. I've made some loadie mistakes reading the correct line on my calendar or simply fuzzing out, and overdosed or otherwise totally screwed things up.
So I've done some experimentation by accident.
I've always cat drenched my plants late into flowering - just started that way and kept it up as a habit. I ran some plants in mineralized soil before I got the kit going and the drench pretty much ruined those, so I have a healthy respect for it and am always a little hesitant to do it. I even ran a couple plants without it and they did really well. A few times I've also done a third drench 2-3 weeks before finish. After all of that, I've come to my own workable understanding of what it is and what it does and what that's good for.
Cat drench releases nutrients that are currently locked up in ionic compounds unavailable to the plant. These compounds always exist in the soil. The nutrients released by the drench and the drench itself are tilted to blooming energy, so when the plant gets that surge it will put those resources into blooming. The approach to high brix that we're using relies on plant growth regulators and other hormones to regulate and enhance vegging when we want it and blooming when we want it. We cycle the plant between veg enhancers and bloom/root enhancers. In the process, we cycle the soil and its biota, too. We encourage it to grow roots, and then foliage, then more roots, more foliage, then flowers, fatter flowers, more flowers, fatter flowers, chop.
So, that's why you can drench the plant at wildly different times. It's another one of those arts of the grow. In my case, by drenching later than most do, I realize/think that what I'm doing is extending the bloom. My blooms are fully set and almost mature when I drench, and they always pause and brown-up before restarting with big fat sticky calyxes. I don't necessarily recommend it. I'll probably start drenching earlier now that I'm getting a better feel for what happens. I want to try to catch the bloom surge before its peak instead of after.
That explanation fits for me. It explains why an early drench gets you small tight buds - you encourage the plant to exhaust everything in one big surge. It the dench comes a little later, the plant will grow more calyxes but the soil might not have enough oomph to fill them out completely, so the yield is higher but maybe not fully ripened. If you drench late, you interrupt the finish and bulk up everything the plant has made, provided the soil can handle it. I run at the limits of my soil/biota the way I do it. I need to see how the soil supports plants that peak earlier in bloom.
If I'm advising someone, I'd say to consider the arc of the bloom, and decide when you want to give them that boost. My plants typically show budding pistils at about 10 days after the flip, so that's the first 1.5 weeks. They're in "full bloom" at about 3-4 weeks. That's the time frame the instructions are pointing at. You're looking for what you think is peak blooming time, and then you smack 'em with a bunch of fun new stuff to eat. But the timing is art.
So says Graytail. Whaddy think, Doc?
