The flush

[AdamAdm]

Hello again to everyone! I've been reading a lot about flushing and there's so much info that contradicts the last thing you read. Is the final 2 weeks (the flush) when buds gain the most weight? Also, there are so many people who claim that flushing in general is unnecessary, and that the quality of smoke and taste come from proper curing instead of the flush. Looking forward to hearing what you guys have to say! Cheers!

 

[farside05]

This and This. Flushing is an urban legend. You cannot "flush" nutrients from buds.

 

[Buds Buddy]

This and This. Flushing is an urban legend. You cannot "flush" nutrients from buds.

I agree with you on not being able to flush nutes from buds. But my question would be, If you do a proper flush 2 weeks prior to harvest & only water thereafter .... wouldn't the flush remove most the nutes from the soil in turn reducing uptake of nutes to the plant ? Not sure if things work that way. Just sounds logical is all.

 

[013]

Outside of weed there is no such thing as flushing. Flushing does not happen in agriculture, nor in fruit orchards or vineyards, not even in organic farming. How does one flush 75 acres of cucumbers? Cant be done...

Flushing can fix some soil problems but thats the extent of it, flushing does not improve taste or remove nutes from your buds.

 

[Buds Buddy]

Outside of weed there is no such thing as flushing. Flushing does not happen in agriculture, nor in fruit orchards or vineyards, not even in organic farming. How does one flush 75 acres of cucumbers? Cant be done...

Flushing can fix some soil problems but thats the extent of it, flushing does not improve taste or remove nutes from your buds.

I agree with all that & I don't flush unless I have a toxicity. I'm not talking agriculture & 75 acres. I'm talking about a 5 gal. pot of soil. I'm not questioning whether it improves taste, smoothness or if it removes nutes from the buds.
I'm questioning if you flush a 5 gallon pot of soil with 15 gallons of water 2 weeks before harvest & then only feed water after that .... "Would it remove most the nutes from the soil & therefore decrease nutrient uptake to the plant" ? I think that's what happens & then the plant takes the nutes from the leaves. I rarely get a yellow leaf. Probably because I feed to the last day. I'm just wondering if my thinking is correct on what I think happens.

 

[Tazmania bud devil]

I believe "flushing" or starving, as no notes with water, simply ensures the plant has taken all available nutes it requires when flowering and then once soils no longer a option, it shall start to drain its leaves mainly fan. Hence the reasoning for yellowing in late flower prior to harvest.

 

[Bill284]

Hello again to everyone! I've been reading a lot about flushing and there's so much info that contradicts the last thing you read. Is the final 2 weeks (the flush) when buds gain the most weight? Also, there are so many people who claim that flushing in general is unnecessary, and that the quality of smoke and taste come from proper curing instead of the flush. Looking forward to hearing what you guys have to say! Cheers!

Hello again to everyone! I've been reading a lot about flushing and there's so much info that contradicts the last thing you read. Is the final 2 weeks (the flush) when buds gain the most weight? Also, there are so many people who claim that flushing in general is unnecessary, and that the quality of smoke and taste come from proper curing instead of the flush. Looking forward to hearing what you guys have to say! Cheers!

Hey Adam how are you my friend. Flushing nutrients from your buds is a myth. But some nutrient lines call for a flush of the pot before the final stages of flower. To clean out salt buldup.
If your nutrient line calls for it then do it. If not and she is healthy and eating well
let her be.
Hope that's helpful.
Bill

 

[Pbass]

I flush when I run out of nutes, but that's it. Why would you ever not want your girls getting their vitamins? As for instructions, I guarantee they tell you to put more in than your plants are going to use. <sarcasm>But don't worry, they tell you to flush out all that good nute you wasted and re-add, so you'll be ok.</sarcasm> CHeers, gl!

 

[013]

Shit I could be wrong here but I believe we are of the same opinion. For those very reasons you mentioned I avoid flushing at all costs, for me its a last ditch safety net, like if I spilled something or heavily overferted. I feel strongly that flushing weakens my soil which in turn weakens the plant in that soil... and I’m often amazed at folks who show up on the faq boards with a weak plant in coco that has been under nuted and over flushed and the advice given often says yep flush her again. Those last few weeks are critical for bud swell and ripening so my typical mantra is feed to the end and don’t flush.

 

[Nunyabiz]

Fortunately I grow in LOS so there's never harsh salts or any other sadness to flush from the soil.
But starving your plant right at the start of its fattening stage makes no sense to me.
It does nothing for the taste of the bud and just cuts your yield by about 10%

If you use salt based bottled nutrients then a soil flush of 3x the pot volume sometime during flower could be beneficial just to remove excess salt and reset the soil.
But starving the plant the final two weeks serves no real purpose.

 

[Emilya Green]

Flushing is one of the most misunderstood concepts in the cannabis growing world. First, we need to define what the word flush means. Are we referring to the act of giving only water for the last week or two, or are we talking about moving 3x the container size in fresh water through the soil?

I will take each of these in turn to try to add some clarity to the universe. Regarding giving only water at the end, for a week or even two... When we compare growing methods to see the effectiveness of only water at the end, we first have to consider an organically grown plant, where all the nutrients are built into the soil, and because of that, there is no way to starve the plant at the end because giving only water is the same as any other regular watering throughout the life of the plant. Because these plants have all the nutrients they need, right up to the end, they end up being of much better quality than non organically grown plants. The buds experience their fastest growth rate during the last two weeks and can oftentimes double is size and weight during that time. The organically grown plants have everything they need to make this happen, but a plant being starved of nutrients during this critical time will not. The difference in quality is striking, and if you don't believe it, do an experiment early in your growing career to compare side by side a plant starved in the end, and one that has been properly fed. You will soon become a believer and you will likely never want to "flush" by giving only water at the end, ever again. It also used to be believed that we needed to clear all the nutrients out of the plant so as to make the final smoke smoother and non chemical tasting. This has been debunked, and we now know thanks to spectrum analysis of the buds, that nutes do not reside in there and there is no way to "flush out" the sugars and nutrients that are in there. A proper cure is the only way to get the smoke to smooth out and to bring out its natural flavors. Starvation has nothing to do with it. Feed your plants right to the end, and even consider giving extra P and K to help them finish out with everything they need.

Next, the traditional meaning of the word "flush"... meaning to move 3x the container size of fresh water through the soil.
Soil has the ability to hold ions of nutrients for later use by the plant. Soil has a specific cation exchange rate... or the amount of nutrients that can be held and then exchanged with the plant. The problem is that over time, as chelated nutrients are unlocked, the salt that is left behind takes up available storage spots in the soil. As the salt accumulates, the soil's ability to hold additional nutrients is reduced. Build up enough salt in the soil, and you can get to what is called a "salt lockout" where there is no more room for nutes in the soil.

This when we do a flush... and pour 3x the container size through the soil, to clean it out. Water effectively dissolves the salt and "flushes" it right out of there. The non water soluble nutrients that are cooked into the soil can not be dissolved and washed out, only the water soluble nutes that might be building up in the soil from repeated applications of nutrient. Contrary to some of the comments above, the good stuff does not wash out of the soil with a 3x flush... just mainly the built up salt. There is no downside to flushing... it provides a reset. There are those who will tell you that a flush will mess up the ionic balance in the soil and harm the plant, but this is nonsense. Flushing for many years was the go to first step in solving a nutrient problem, resetting everything to zero and starting fresh. The best advice I have heard about 3x flushing is that at the minimum, if you are running chelated nutes, give a proper flush at the 6 week point, just before the buds begin their final swell to finish out. This clears the pipes, removes all the salt and allows for strong uptake of water and nutes during that final two weeks. A flush at the very end, to clean out the product for smoking, is not only worthless due to reasons given in the discussion above, but it is 2 weeks late to do any good in regards to a spectacular finish.

 

[AdamAdm]

Outside of weed there is no such thing as flushing. Flushing does not happen in agriculture, nor in fruit orchards or vineyards, not even in organic farming. How does one flush 75 acres of cucumbers? Cant be done...

Flushing can fix some soil problems but thats the extent of it, flushing does not improve taste or remove nutes from your buds.

This makes a lot of sense. Thanks very much. Where has the whole thing with flushing weed come from then? Who decided that weed must be flushed and when lol?

 

[Emilya Green]

Outside of weed there is no such thing as flushing. Flushing does not happen in agriculture, nor in fruit orchards or vineyards, not even in organic farming. How does one flush 75 acres of cucumbers? Cant be done...

Flushing can fix some soil problems but thats the extent of it, flushing does not improve taste or remove nutes from your buds.

Flushing is unique to container growing. In that enclosed space, flushing can often times be necessary. Salt does not build up in the soil outdoors.. it just flows away. In a closed container, it has no where to go and as it builds up, it can harm the grow. YOU CAN NOT COMPARE OUTDOOR GROWING IN THE SOIL WITH CLOSED CONTAINER GARDENING.

 

[AdamAdm]

Flushing is unique to container growing. In that enclosed space, flushing can often times be necessary. Salt does not build up in the soil outdoors.. it just flows away. In a closed container, it has no where to go and as it builds up, it can harm the grow. YOU CAN NOT COMPARE OUTDOOR GROWING IN THE SOIL WITH CLOSED CONTAINER GARDENING.

This also makes a lot of sense haha! Thanks very much for your replies. Happy smokin!

 

[bobrown14]

I agree with you on not being able to flush nutes from buds. But my question would be, If you do a proper flush 2 weeks prior to harvest & only water thereafter .... wouldn't the flush remove most the nutes from the soil in turn reducing uptake of nutes to the plant ? Not sure if things work that way. Just sounds logical is all.

Read up on Cation Exchange Capacity

Cations and Cation Exchange Capacity | Fact Sheets | soilquality.org.au

You soil has the ability to hold onto cations. Its a electrical/chemical bond. Water has an electrical charge of ZERO so there's nothing in water that attracts fertilizers that are electrically bound to soil particles.

The higher the CEC of you soil, the less likely you will be able to induce fertilizer leaching. Even with a low CEC like sandy soils its the excess N that leaches out. We shouldn't be adding excess N during flower right? So there wont or shouldn't be excess N in the soil.

Hope that makes sense.

 

[safeman]

I agree with you on not being able to flush nutes from buds. But my question would be, If you do a proper flush 2 weeks prior to harvest & only water thereafter .... wouldn't the flush remove most the nutes from the soil in turn reducing uptake of nutes to the plant ? Not sure if things work that way. Just sounds logical is all.

no -- one can /should feed during flush why "strave" the plant for two weeks - I use a fish fertilizer durin the last two weeks (product: Fish Shit.com - can get sample bottle for $5.00 - this product is relativlity new ( if you use chemical nutes use 1/4 amounts )

 

[Diatomacious]

I've been reading a lot about flushing and there's so much info that contradicts the last thing you read.

I smush some crystal from a big frosty fan leaf and take a good whiff. If it smells like you want to smoke it right then, you are good. If it smells like a bag of fertilizer then flush.

 

[AdamAdm]

Read up on Cation Exchange Capacity

Cations and Cation Exchange Capacity | Fact Sheets | soilquality.org.au

You soil has the ability to hold onto cations. Its a electrical/chemical bond. Water has an electrical charge of ZERO so there's nothing in water that attracts fertilizers that are electrically bound to soil particles.

The higher the CEC of you soil, the less likely you will be able to induce fertilizer leaching. Even with a low CEC like sandy soils its the excess N that leaches out. We shouldn't be adding excess N during flower right? So there wont or shouldn't be excess N in the soil.

Hope that makes sense.

So realistically flushing for a fortnight isn't worth it?

Hey Adam how are you my friend. Flushing nutrients from your buds is a myth. But some nutrient lines call for a flush of the pot before the final stages of flower. To clean out salt buldup.
If your nutrient line calls for it then do it. If not and she is healthy and eating well
let her be.
Hope that's helpful.
Bill

Hi Bill, I'm good mate thanks I hope you're well! Thanks man, that helps a lot. Have a nice Sunday my friend.

 

[goofyfoot]

If you over feed your plant it will help to clear the SOIL / MEDIUM and like mentioned. With a container plant if you push a bunch of PH'ed water through the soil. It will help remove salts that have built up. Making way for the transition from Veg to Flower.

There is a trick if you don't want the plant to take up any additional nuit's that are still in the soil / medium. The last 7 to 10 days / 2 weeks before you cut them. Only give them water at a PH higher then 8.5, you cause lock out on purpose. Anything PH'ed below 7 the plant will try and take in, above that it can't.

They still can drink but you restrict the roots from pulling up more nuit's into the plant. The plants will finish with what it has built up inside itself.

Most of the nuit's are derivatives of metals and water will not remove them from the PLANT. An example in humans some have to much iron in their blood. You need to have blood removed and a transfusion to remove it from your body.

 

[safeman]

I smush some crystal from a big frosty fan leaf and take a good whiff. If it smells like you want to smoke it right then, you are good. If it smells like a bag of fertilizer then flush.

another way to see if 'chemicals" ini your smoked pot is color of sah: Black color means chemicals and will probably taste some waht harsh, ect - - whit ash means "clean" pot No growing nutrients