Flush before Harvest

[NoWorryLeaf]

What is you opinion on flushing before – I do it but recently on FB some grow members says it does not do anything.

[Atom]

You want to give strait water last two weeks so the plant can use up its nutrient stores, if everything goes well. Buds are sinks though and only take in nutrients and never release them, so if you have over fertilized you can never flush that out, and will make for harsh smoke and probably not taste very good. If your plants are still pretty green at the end I’d say flush. If there hurting for nutes, dropping alot of leaves keep giving nutes. There’s also 2 types of flush. One is just giving strait water at the end of cycle. The other is literally Flushing the soil with copious amounts of water, mostly to remove salt build ups, or to try and correct nutrition.

 

A few things I’d like to point out is everyone grows differently, have different set ups, use different nutes. It’s hard to say do this, not that because of it. Also each strain might require more or less nutrients. Alot of different factors go into nutrient uptake, if it’s a new strain it will probably take atleast a run to learn how the plant will do in your set up.

[Keith]

This was a great explanation.

[Brad104]

Great reply Adam marsh I am at the end of my peyote gorilla 🦍 grow and I started them on straight water a week ago and I will be cutting by the end of this week it’s 10 weeks and the tricomes are glistening I will put up pictures and a forum topic when I figure out how to post pictures ha as you can tell I’m not a tech guy

[Keith]

This is a good one. There’s so many different opinions, we need a poll. The way i figure it is this, any study I’ve seen is done by a nutrient company. The nute company’s say that no difference is observed in potency or size of buds with or without flushing. However they do say people preferred the taste of the non flushed buds better. Which I have a hard time believing. Why would the nasty smelling stuff in the bottle make my buds taste better? So if there’s no difference in potency or size and i don’t believe nutes would make it taste any better then I’m for flushing. What I did last time was cut back to half strength my 2nd to last week and then nothing the last week. I’m not going to waste nutrients for no reason.

[Atom]

I’m pretty sure I’ve read that article and came to the same conclusion. If it made no difference if you flush or not, why not flush and save 2 weeks worth unnecessary nutrition? The only thing I can think is they lose money.

 

I’ve had to harvest early before but never intentionally not flushed. I will say I noticed a vast difference in both flavor and how well it burns. There was always a bit of ash residue and more gray than white, a bit more harsh. Did it still do the job? Absolutely. But when something taste amazing and burns super smooth I believe that adds to the effects.

 

That being said I like to always try to encourage people to try it in there own. Never shy away from running little experiments. There’s always more to learn I feel like, and every experience helps build confidence in a grower.

[Keith]

Very well said

[Cannabliss]

There have been scientific studies & trials.
on the bottom of the article there are links to other info related to the studies.

https://gpnmag.com/news/rx-green-technologies-study-flushing-cannabis/

[Brad104]

I appreciate your feedback Guys and thank you for it.If I can help you out in any way any of you guys just hit me up and thanks again

[Brad104]

I appreciate your feedback Guys and thank you for it.If I can help you out in any way any of you guys just hit me up and thanks again. I appreciate the link to canabliss

[Cannabliss]

No problem. I’ve actually did a flush & a non-flush grow, and the buds actually finished better imo without the flush.
Using water only when feeding salts will flush the salts out of the medium for sure.
Using organics, it’s hard to flush all those nutrients out of the soil.
Im sure you all have tried some organic grown bud at one point, and there’s no harshness. Well if there is.. the lack of flushing isn’t the culprit. Something had to go wrong during the dry/cure stage.
The dry can make or break your harvest regardless of what the finial weight is or will be.

[Racky]

I didnt flush this All Gas Og and it isnt harsh and isnt even all  cured yet.

[Racky]

[Cannabliss]

That looks awesome!

[Somatek]

The debate around whether to flush or not before harvest was really kicked off by a paper published by the UoG which you can read here.  For normal people who aren’t interested the quick version is the study was looking at optimal irrigation strategies for growing ganga in a controlled enviroment.  The part about flushing was a small blurb where it tests the theory that flushing reduces the mineral content of the finished bud, which it showed was false and had no substance as the mineral content was the same between the test and controlled crops.  That is far from definitive though as their was no blind qualitative testing with a large enough sample to draw relevant data from.  It also didn’t consider the context around flushing which is that it was common advice when growers aimed to slightly over fertilize their crops looking for the “optimal burn” as a sign of proper fertigation instead of using something like a brix meter to dial in the ideal based on solid data.  Remember this was a study looking at optimal irrigation strategies where the test vs crops had every variable controlled and measured from VPD to plant size and biomass yield, etc.  Which is a very different context from growing in the 90’s when flushing was prominent.  Finally they also observed there wasn’t a significant difference between the control and test in terms of yield or potency, which suggests there’s value in flushing simply to reduce your inputs/costs.  There is no clear answer as like most things the science is still being developed.

An interesting side not of that study is that it found that slight water stress at the end of flowering decreased the yield but increased the cannabinoid content and produced a net gain in potency at the cost of yield.  Keep in mind though the level of control they were applying as it’s probably a thin line between boosting vs stunting the plant.

[spaceman79]

I read long ago that if you are using organic nutrients, no flush is needed. I’ve tried both flushing and no flushing and haven’t noticed a difference.

[NoWorryLeaf]

Thank you so much – this is great to know

[Author]

Posts