GreatLife4All
New Member
Lately I have been reading a lot about flushing.
First, let me say that there are many types of "flushing". The two important types for me (I grow hydroponically) are "weekly" flushes and what I will call the final flush. For the purposes of this post, and hopefully this thread, we will restrict ourselves to only discussing the final flush... though I will call it simply flush.
The other thing I need agreement on is the reason behind flushing. Most growers will claim that the final product will improve in taste... or another angle, it decreases the harshness of the smoke. I can find no other arguments supporting this practice. So I am going to assume that "taste" is the reason that people perform a final flush. If you have other reasons, please post up and let me know.
My experiences with flushing are interesting. I don't claim definitive knowledge, but I will share my experiences and thoughts. I have a line of plants (WW) from a single mother that I have grown under many different conditions now over the past nine months. My experience indicates that we are doing flushing wrong. Why would I say such a thing?
Because you get a smaller yield of <possibly> higher quality bud.
Ok... bear with me as I take what will look like a side trip here.
What is happening in the plant during the last two weeks of growth? When I check... I see lots of different names for this period - aggressive bloom, bud swell, and etc. But no matter what it is called, this is a critical period in the development of an MJ plant. Smells develop and mature. Buds are filling with resin. And the plant is undergoing one final major push to produce. So the plant is growing in many ways, just not in physical size.
Why would anyone take away nutrients when the plant most needs them? Doesn't make sense. Ok... I know the argument, the plant is merely moving nutrients from one part to the other. Good argument, but unfortunately it just isn't true in all cases.
For our purposes, there are two classes of nutrients. Mobile nutrients and immobile nutrients. Mobile nutrients are ones that we know the plant can move around inside of itself. The immobile nutrients can only come from the roots - they can not be moved once inside the plant. There are scientific reasons behind this having to do with xylem and phloem that I will skip. If you are interested in the science behind this, let me know and I can give you some pointers.
So which are mobile nutrients? The list is as follows: N, P, K, Mg and S. The other nutrients which are immobile are Ca, Fe, Zn, Mo, B, Cu, and Mn. If you need a layman's thought process to justify this - the mobile nutrients are the ones that cause problems on older growth (they are stolen from old growth to support new growth... thus they are obviously mobile within the plant). The immobile nutrients affect the whole plant at once - and most especially in the areas of growth (the growth shoots or apical meristems) which is at the outside edges of the plant.
The typical recommendation for flushing goes something like this: "For the last two weeks of the flowering cycle, remove all nutrients and use R/O water." Some will suggest a flushing solution which is mostly sugar. In either case, you are severely limiting all nutrients - not just the mobile ones.
So why is this a critical error?
You need to think about what happens when a plant does not have calcium... cell division comes to a halt. This results in "stunted" growth if it occurs during the normal plants life cycle... something we would fight agressively... but we accept it as part of the final flush? Doesn't make sense.
Boron is also essential for new plant growth. Without Boron - you won't get good bud development.
I could go on and point out what each of these immobile nutrients do. But it would be better for you to go and find a source, read about the effects each of these nutrients has, and then decide if that is something that you want stopped during the last two weeks of flower.
The final thing I want to point out is plant stress. You are going from a high nutrient environment to one where you have pretty close to zero. This will obviously put stress on the plant. Think how long it would take for your body to adjust between say... a high fat diet and one based on water. You are not just going to continue in life like nothing happened... The same sort of thing happens to the plant. And plant stress reduces yield.
So I think that I have made my point that flushing is bad due to the science behind growth. But what does actual growing experience tell me?
It is a fact that flushing restricts yield. Don't care the type of MJ plant. I started with two week flushes... then moved to one week to limit the amount of yield loss... and have now moved to 3 days on my latest grow. I can't tell any difference in taste between each of these time frames. And yes, I have had overlapping yields of the same plants genetics - so that I can actually tell.
I believe that flushing produces a hay like smell. This may not be in all cases... but it has happened enough to me that I believe it to be true. WW typically develops a great smell at about 4 to 5 weeks of flowering. I had two grows where I lost that smell in the final product - and those were the two longest flushes. I had some plants recently that were first out of the tent - couldn't flush because the other plants weren't ready. The largest yield and definitely ENHANCED the smell that had been building. Many people claim that this is the best batch of WW that I have ever grown. They knew nothing about the changes in my procedures... and I hadn't really put it together yet. But this grow eight weeks ago was what got me to thinking about things and checking my notes.
I am in the middle of harvest right now... and this one had a three day flush for some of the plants. I don't think the three day flush made much of a difference in yield... but I also don't think that it made much of a difference in TASTE either. Seems like an academic exercise more so than something that worked.
A couple more anecdotes and I am done for now.
I just got done growing a Silver Kush. I didn't flush it and it was the harshest (and best) smoke that I have ever personally grown. I was all over myself about ruining the taste of such great weed by not flushing. But a nine day drying period followed by a 3 or 4 day curing period in mason jars has mellowed the weed right out. No harshness at all now. And the taste gets better every day. Definitely not ruined.
I cut one stalk about two weeks early on the Silver Kush just to give it a try. It dried down to nothing - but was harsh and strong. i did the same thing after harvest - took a branch and dried it down in the oven. It didn't shrink much at all... had way stronger smell (the house filled with a pleasant odor this time)... and the buds had great trichs. None of this would have happened had I stopped the plants growth two weeks ago. And here is the interesting point... I would have been very happy with the yield and quality of that weed that I clipped two weeks ago... had I not had the second sample to compare against.
So I got a great yield (over 3.5 oz with eight other plants in a 4x4 tent) and it is developing great taste - with no flush.
So it would seem to me that the only thing flushing does is to mellow the smoke out between harvest and cure. Or another way to look at it maybe - it allows you to either skip the cure entirely or to limit the curing time. I can end up with great smoke using either method... and in fact I can't really tell much difference after the cure is finished. So, at best, you can try to convince me that the small difference (that I can't notice) is worth the loss of yield... and I won't buy that pony.
And with that statement, I will accept the far greater yield, taste, and THC production afforded by not flushing... and accept that I must do a proper dry and cure to get rid of that nasty taste.
I would appreciate any thoughts on my thoughts....
First, let me say that there are many types of "flushing". The two important types for me (I grow hydroponically) are "weekly" flushes and what I will call the final flush. For the purposes of this post, and hopefully this thread, we will restrict ourselves to only discussing the final flush... though I will call it simply flush.
The other thing I need agreement on is the reason behind flushing. Most growers will claim that the final product will improve in taste... or another angle, it decreases the harshness of the smoke. I can find no other arguments supporting this practice. So I am going to assume that "taste" is the reason that people perform a final flush. If you have other reasons, please post up and let me know.
My experiences with flushing are interesting. I don't claim definitive knowledge, but I will share my experiences and thoughts. I have a line of plants (WW) from a single mother that I have grown under many different conditions now over the past nine months. My experience indicates that we are doing flushing wrong. Why would I say such a thing?
Because you get a smaller yield of <possibly> higher quality bud.
Ok... bear with me as I take what will look like a side trip here.
What is happening in the plant during the last two weeks of growth? When I check... I see lots of different names for this period - aggressive bloom, bud swell, and etc. But no matter what it is called, this is a critical period in the development of an MJ plant. Smells develop and mature. Buds are filling with resin. And the plant is undergoing one final major push to produce. So the plant is growing in many ways, just not in physical size.
Why would anyone take away nutrients when the plant most needs them? Doesn't make sense. Ok... I know the argument, the plant is merely moving nutrients from one part to the other. Good argument, but unfortunately it just isn't true in all cases.
For our purposes, there are two classes of nutrients. Mobile nutrients and immobile nutrients. Mobile nutrients are ones that we know the plant can move around inside of itself. The immobile nutrients can only come from the roots - they can not be moved once inside the plant. There are scientific reasons behind this having to do with xylem and phloem that I will skip. If you are interested in the science behind this, let me know and I can give you some pointers.
So which are mobile nutrients? The list is as follows: N, P, K, Mg and S. The other nutrients which are immobile are Ca, Fe, Zn, Mo, B, Cu, and Mn. If you need a layman's thought process to justify this - the mobile nutrients are the ones that cause problems on older growth (they are stolen from old growth to support new growth... thus they are obviously mobile within the plant). The immobile nutrients affect the whole plant at once - and most especially in the areas of growth (the growth shoots or apical meristems) which is at the outside edges of the plant.
The typical recommendation for flushing goes something like this: "For the last two weeks of the flowering cycle, remove all nutrients and use R/O water." Some will suggest a flushing solution which is mostly sugar. In either case, you are severely limiting all nutrients - not just the mobile ones.
So why is this a critical error?
You need to think about what happens when a plant does not have calcium... cell division comes to a halt. This results in "stunted" growth if it occurs during the normal plants life cycle... something we would fight agressively... but we accept it as part of the final flush? Doesn't make sense.
Boron is also essential for new plant growth. Without Boron - you won't get good bud development.
I could go on and point out what each of these immobile nutrients do. But it would be better for you to go and find a source, read about the effects each of these nutrients has, and then decide if that is something that you want stopped during the last two weeks of flower.
The final thing I want to point out is plant stress. You are going from a high nutrient environment to one where you have pretty close to zero. This will obviously put stress on the plant. Think how long it would take for your body to adjust between say... a high fat diet and one based on water. You are not just going to continue in life like nothing happened... The same sort of thing happens to the plant. And plant stress reduces yield.
So I think that I have made my point that flushing is bad due to the science behind growth. But what does actual growing experience tell me?
It is a fact that flushing restricts yield. Don't care the type of MJ plant. I started with two week flushes... then moved to one week to limit the amount of yield loss... and have now moved to 3 days on my latest grow. I can't tell any difference in taste between each of these time frames. And yes, I have had overlapping yields of the same plants genetics - so that I can actually tell.
I believe that flushing produces a hay like smell. This may not be in all cases... but it has happened enough to me that I believe it to be true. WW typically develops a great smell at about 4 to 5 weeks of flowering. I had two grows where I lost that smell in the final product - and those were the two longest flushes. I had some plants recently that were first out of the tent - couldn't flush because the other plants weren't ready. The largest yield and definitely ENHANCED the smell that had been building. Many people claim that this is the best batch of WW that I have ever grown. They knew nothing about the changes in my procedures... and I hadn't really put it together yet. But this grow eight weeks ago was what got me to thinking about things and checking my notes.
I am in the middle of harvest right now... and this one had a three day flush for some of the plants. I don't think the three day flush made much of a difference in yield... but I also don't think that it made much of a difference in TASTE either. Seems like an academic exercise more so than something that worked.
A couple more anecdotes and I am done for now.
I just got done growing a Silver Kush. I didn't flush it and it was the harshest (and best) smoke that I have ever personally grown. I was all over myself about ruining the taste of such great weed by not flushing. But a nine day drying period followed by a 3 or 4 day curing period in mason jars has mellowed the weed right out. No harshness at all now. And the taste gets better every day. Definitely not ruined.
I cut one stalk about two weeks early on the Silver Kush just to give it a try. It dried down to nothing - but was harsh and strong. i did the same thing after harvest - took a branch and dried it down in the oven. It didn't shrink much at all... had way stronger smell (the house filled with a pleasant odor this time)... and the buds had great trichs. None of this would have happened had I stopped the plants growth two weeks ago. And here is the interesting point... I would have been very happy with the yield and quality of that weed that I clipped two weeks ago... had I not had the second sample to compare against.
So I got a great yield (over 3.5 oz with eight other plants in a 4x4 tent) and it is developing great taste - with no flush.
So it would seem to me that the only thing flushing does is to mellow the smoke out between harvest and cure. Or another way to look at it maybe - it allows you to either skip the cure entirely or to limit the curing time. I can end up with great smoke using either method... and in fact I can't really tell much difference after the cure is finished. So, at best, you can try to convince me that the small difference (that I can't notice) is worth the loss of yield... and I won't buy that pony.
And with that statement, I will accept the far greater yield, taste, and THC production afforded by not flushing... and accept that I must do a proper dry and cure to get rid of that nasty taste.
I would appreciate any thoughts on my thoughts....
(just make sure you dont have a humidty spike... in lots of rooms if you cut the lights for that long you risk rising humidity and therefore mold)
All this talk about this is better or that's better and... maybe it doesn't really matter much. I got a chuckle out of it. 
