In this watering thread you have seen me change my opinions about aspects of this watering thing, two or three times. This thread is an exploration of my learning process as I have continued to study watering over a 10 year period of time. While several years ago I thought that pushing water at the plants in bloom and keeping the rootball moist was a great idea, in 2020 I have seen indications over several grows that there is a better way, and I have learned to appreciate the results that can be achieve by introducing minor stressors to these plants.
Yes, I am talking about the slumping drooping effect of the entire lower leaf sets that indicates the need for water, not the clawing at the ends of leaves. By the time this lower fan drooping is happening you have about 12 hours to go before all of the water is gone from that container. Waiting for that drooping indication is taking the water level in that container down to the last inch or two and by that time most of the roots have had a hit of oxygen. By this time in the grow, the very lowest roots, those that sit in wet most of the time, they have adapted to be able to survive in that very wet zone, and they stay healthy and active, unlike what happens in veg.
The microbes can also survive much more of a drought than what we are considering here. Also realize that in a normal watering cycle, the top 2/3 of the container gets pretty darn dry. If this was going to kill microbes, we would all be in trouble, and container growing would not work. Thankfully, those little beasties are a lot more resilient than that, and they can simply hibernate until water arrives again, and then they spring right back into action. We do not need to keep our soil moist in order to protect microbes. Besides that, there are many places to hide in that soil where water remains in small amounts, and in those little pockets inside the perlite and other organics, the microbes are still going strong. Give them water and 20 minutes or so to reproduce, and the population starts doubling exponentially.
There have been a lot of studies about the effects of stressors on these plants, and one of the most common stressors is drought. In veg we see that this stressor causes the plant to grow more roots as a response. What is happening in bloom when we do this, since the roots have pretty much stopped growing? This, I believe, is when the plants produce their defence to the drought, more resin and more trichomes. Some people believe in really sending their plants into stress with extended drought toward the end of the grow to increase trichomes. I have realized that this can also be done all through bloom, without detrimental effects.
So is the droop really an indication of stress, or simply a physical reaction to the plant not being able to draw up as much water as it could when a larger percentage of the roots were seeing water? I am beginning to believe that this is really not stressing out the plant as much as we might think, and that the leaves dropping below the horizontal is simply a visual indicator that we can observe to gain knowledge as to the water levels in that container. If you let the droop go up to the top, with actual trunk bending WILT happening next, that surely is stress that we should try to avoid... but catching it early as the water pressure in the trunk just starts to drop... I don't think it is a biggie, and I think it grows more trichomes.