To flush or......???

[TheGreenGiggler]

So I am looking for discussion on the topic of flushing, so lend me your thoughts. I stumbled across a bit of chatter where someone was asking for the justification of flushing, and the point expressed was “isn’t that like starving the pant in its peek?” Which I had some trouble discounting in my feeble mind.... so here’s my request....

Help me understand if it’s needed and why? In theory if your treating your plant properly is there a need? If so I’d also like opinions on how much or how long for soil grows with nutrients.

Best,
me

[DoctorJohnson]

I think of flushing pots as a gardening practice in much the same way that I think of the ancient practice of bleeding patients as a medical practice: it's popular and people attribute beneficial properties to it, but unless the plant has been overfertilized, it's unnecessary at best and harmful at worst.

There are a lot of folk remedies and practices in cannabis gardening that people swear by but that are not scientifically validated and that are actually pretty loopy if you think about them a little bit.

Give your plants the light, water, air, and nutrients they need and not a lot expensive extra stuff in fancy bottles with colorful, sexy labels and then leave well enough alone.

[TheGreenGiggler]

Thanks! I am hoping to gain multiple points of view on it. If only I knew it all!! Course then I’d be bored..

[D.A.A.S.69]

Morning giggler, you need to read Nebulas articles on flushing, some do some dont, but if you cut back on nutrients at the end that will help alot. Most of the time I grow in supersoil, so I don't flush sometimes ,but not always.

[TheGreenGiggler]

Thanks D.A.A.S.69, I might be a little dim.... I don’t know if I understand the steps of some of the tutorials I have read... does one hose them down daily to run off or just use water in the same amounts as a normal watering for a few weeks? Is there anything to do around shortening the time frame?

[oldjarhead100]

I find flushing useful on two occurrences One when plants stop feeding (lockout) if you flush then you are washing away the problems and as a final flush ,if you start decreasing nute around week 7 and just give them Molasses and water for 3 or 4 watering then flushing is not needed but if you use nutes right up to harvest week then you need to Flush

[D.A.A.S.69]

That's almost exactly the same way I feed mine Garrett, same as you. You want fat buds you gotta feed them, I use Advanced Nutreints but I use molasses the whole grow.

[Garrett]

D.A.A.S.69 Cool cool I have heard great things about the Advanced Nutrients. How do you use your cal mag?

[D.A.A.S.69]

Hey Garrett, I start at 5 ml/gallon at the beginning of the grow, 3 ml/gallon for the rest.

[kingfish]

I don't flush. I just stop feeding them about 2 weeks before harvest.

[TheGreenGiggler]

Ok, can some one explain flushing in detail? Is it a one time thing? Is it a daily? I am interpreting it as one of two things. A full drench to create a significant run off from the soil, as a one time event. Or is it just watering with out any nutrients for a period of time, ie 7 days to 14 days in soil....?? ( or is it drenching for 2 weeks with large run off....)

little more help? (Thanks for all the input thus far gang!)

[St.buds]

There are products to add to your water to help strip the salts and nutes out without having to run tons of water threw your pots. I use flora kleen from gh

[Garrett]

The term “flushing” gets used for both. oldjarhead100 explains it in a few comments up. Your preharvest flush is a 2 week long process in which time you will give ph’d water with no nutrients at the time you would regularly feed. Maybe molasses.

[Flockshot]

I grow in coco, with GH nutrients. So this pertains to coco with GH nutrients.

Runoff PH determines when I flush. The runoff PH will drop over time as salt builds up in my coco. I generally will flush (5 gallons of PH'd water, with FloraKleen as directed), for each 5 gallon smart pot of coco.
I grow in 32oz cups, and then 1 gal pots, then 5 gal pots. This way I am not building up salts in a 5 gallon pot when the plants are small.
I will probable flush at about 5-6 weeks of flower, the same way.
Then when I determine I have about 2 weeks to go I flush with every watering (about 3 times), but this is with plain PH'd water, not the FloraKleen.

I have flushed, and I have not flushed. Flushed is much better imo.

True living organics, in soil, no flush necessary. Pretend organic grows with 'organic' bottle nutrients, I do recommend a flush. my 2c.

[alltatup]

Giggler, there's controversy about flushing: I keep lowering my nutes in the final weeks of flowering, so I haven't flushed and there is no harsh bud in my harvest. Here are some articles:

https://www.thcfarmer.com/community/threads/flushing-is-a-bad-practice-based-on-flawed-science.64789/

http://support.ilovegrowingmarijuana.com/t/to-flush-or-not-to-flush/6432

http://www.thenorthwestleaf.com/pages/articles/post/why-a-plants-final-3-4-weeks-of-grow-are-so-important

[TheGreenGiggler]

Thanks all! Going to read the articles now!! Is there any scientific testing that outlines the differences? Forgive me for how I will ask this part..... by scientific testing, I mean lab quality type stuff rather than anecdotal evidence?

[TheGreenGiggler]

That might take me some time to poor over, thanks for suggesting the articles alt! Might be week minded, but the way I read so far has me leaning one way atm. If I expressed a view on that would you all mind gently pointing out the parts I misinterpret or fall short of thinking through to all of the available considerations?

My thoughts chain together like this.

All living things need food to continue, this includes at points where they are significantly ageing. A plant will burn food as part of its live cycle. A plant will not burn all stored foods if they exceed its normal needs for production or continued living. A plant will also not burn injested material that can not be considered food, meaning excess amounts of “food/nutrients” and/or foreign elements would build up with in the plant. Flushing could potentially blend down this stored excess stored foods as the plant would begin using its stored foods, but it would not wash out excess foods and unusable stored elements as this would not be a possible outcome. Am I getting this right so far?

If it’s the plant using it’s stored material, how much could their be? I would imagine their would be a density ratio that limits the amount of material, Think anyone is or has looked into how much fertilizer a plant can internalize for a period of time and how long a plant can take to burn a fully saturated plant?

[oldjarhead100]

ok Green you nailed it ,the purpose of flushing is to wash out the unused food/nutrients from soil, then the plant uses up its stored nutes so you do not have a bad taste in the buds.

If you lower the amount of nutes you feed the plant it starts to use the stored food while its still growing

[TheGreenGiggler]

Thanks! That insight it super helpful.

[alltatup]

GreenGiggler, Here's how I see it: The leaves tell the whole story. Are they perky, perfect color, vibrating with energy? Then the nutes are fine.

I am very conservative with my nutes, and I feel out how much to use by looking closely at the leaves. And since I decrease my nutes each week after week 4 of flower, I don't need to flush my plants. I don't believe in completely depriving them at a crucial time, and my buds are never harsh. My nutes are really low, like seedling strength, at the end of my grow.

I'm doing a flush this weekend just to give them a breather, and I usually end on a 2 day flush.

[TheGreenGiggler]

Appreciate your help and thoughts! We should send this to myth busters, best episode ever!

[alltatup]

You're welcome! My "feel" for what I'm doing with nutes is getting better little by little, I hope...

[Garrett]

You aren’t busting any myths. If you use full strength nutes till the end then you need to flush. If you lower the dose at mid to late flower it isn’t as nessassery. alltatup still does a two day flush at end. alltatup How much do you flush with on those two days?

[alltatup]

What do you mean, How much? I put in the same amount of water with some Flawless Finish.

[TheGreenGiggler]

@ Garret - Sorry, I was implying it would be cool if someone ran a lab test to dissect and test the molecule composition of a flushed bud versus a bud that had not been, as well as some of the other options such as reducing the notes with a shorter flush.

It would be super cool to understand the effects and differences that the different methods provide as and end result. (Least in my head it seems like it would be cool. The reference to myth busters was simply cause a commercial was on and they do that sorta thing. (Was not implying that flushing or not flushing is a myth, I am not settled in either camp as I don’t know enough yet).

[Garrett]

alltatup. Ok cool. I don’t use any flushing agent. I “flush” with a larger quantity of water than when I feed or just water. TheGreenGiggler man I looked all over for test results. There are test being done on chemicals that were used on the cannabis, you would think there would be a similar test stating the say NPK levels pre cannabalisim and at harvest times for both the buds and the fan and sugar leaves.

[Garrett]

alltatup do you do that flush any specific time, or when you feel nessessary?

[alltatup]

Garrett I look real closely at my leaves. I look to see what's going on with the older and lower leaves. If I see signs of too much nutrient, that's when I will flush them. Some folks recommend a 2 day flush every week, but it's just too much water lugging for me, so I don't do it that often.

Last week I was examining leaves and seeing a tiny bit of tip burn and some spots on older, lower leaves, so I decided to flush.

I can see that my leaves are really happy and perky today, the second day of their flush. I read (can't remember where, but it's in my notes) that the plants love the break and explode with growth after the flush, and you can see during the flush that they get happy.

[Garrett]

alltatup Ok ok I may try to work that into my regimen.

[Garrett]

TheGreenGiggler But. Lol if the nutrients are being leached from other parts of the plant, does the bud know exactly how much to take from the rest of the plant to finish its cycle? We cut that plants life short, so wouldn’t the plant have more stored nutes. And does the nutes in the bud get used up, can’t be completely. But idk.lol

[oldjarhead100]

If there are no nutrient left in the soil the plant has no choice but to use its stored nutrients

[alltatup]

As I mentioned above, there's still quite a bit of controversy--or at least disagreement--about whether it's needed or not. Ed Rosenthal notes that outdoor plants aren't flushed.

[Garrett]

To each his own. I don’t have a problem either way. I have smoked unflushed and flushed.

[alltatup]

And...? Was there a difference in the smoke?

[Garrett]

alltatup Man, I didn’t notice a difference. But that’s the conclusion that I hear from most people.