Do You Flush Organic Grows Before Harvest?

I had it in my head that you flush Chem fert grows, but not organic. Maybe some organic people flush also?

Yup. Organic hydro is fully capable of running a flush/starve/feed regime just like the mineral hydro guys. There are a few things that make it more complicated. You need a way to separate some of the nute water in your reservoir during flushes to keep your bennies alive. Other than that it is very similar. I usually flush and starve twice during flower and once again at harvest. I use DNF clear to strip off old gunk and salt and to leech the nitrates out of the plants. I actually think organic medium hydro is a bit better for this at the end. Flush the plants and let them get dry in the organic medium. Existing micro-life will continue to feed the plants a small life-line of moisture and nutrients. This slows the final leeching process and allows the plant to get dryer while still attached to it's roots. This reduces hanging/curing time and dramatically decreases the starch content of your bud (very desirable)

Flush/starve regimes can have strong effects on the yield of a cannabis plant. It is a trick the mineral hydro guys have been using to make our organic yields look bad for YEARS. I say its high time we took the method for ourselves, I think it can benefit organic growers a lot.

-DM

Interesting. Thank you. I recently read a study that had possible indicators that a water restriction increased resin. Have you had any indications of this during your starve periods?

Oh heavens yes. The starve cycle triggers a fascinating array of responses from the cannabis plant.

During the starve the plant 'thinks' (I know plants can't think) that it is dying. It responds immediately by doing everything in its power to save the seeds. This means sending all available sugars, resins, auxins, starches, blah blah blah to the buds. Now, if you are growing cannabis to smoke then you took care not to pollinate your ladies. That means all of the resources that the plant sends up to the flowers in an effort to save the seeds winds up going towards trichome production instead! A reduction of water can cause this but it helps big time for there to be a lack of nutrition as well. Nutrients tend to linger around a little longer with organics so care must be taken to flush completely.

A lot of other cool things happen when you starve. Resin and oil production dramatically goes up when mosture becomes scarce. This is because up to a point the oils that cannabis produces are able to take the place of water for some tasks. Maintaining turgidity, propping up the cell structure and keeping the sap layer free-flowing are all things that oil can do when there isn't enough water around. However oil cannot replace water for any of the plant's metabolic processes and is still necessary for it to produce more food. Pushing the girls into a state of wiltiness and Nitrogen deficiency makes them 'hungry'. Evolutionary programming indicates to their body chemistries that they have just gone through a drought/famine. As a result when water and nutrients become present again the plants will take off into furious bud development. They will take up even more water and nutrients then they would have without the starve. They are in a mode of panicked energy storage for fear that another drought might come.

(Now I know that talking about plants this way is horribly un-scientific. Plants do not panic, they do not feel fear, these are all human emotions that I have applied to what is in reality little more than an inanimate object. These 'feelings' are actually a form of programming. It is simply a large array of yes/no switches. Each switch has been tuned to respond to different sets of stimuli. By changing these stimuli we can manipulate what the plant does. Every cannabis gardener already does this by maintaining a long day for veg and then switching to 12/12 for flower. There are a lot of other ways to prod a plant's genetic switch-box and the flush-starve cycles push a lot of these buttons. If controlled correctly it can create a response from the plant that is desirable as it increases potency/budmass/flavor/burning characteristics/etc.)

These changes are all very apparent to the grower. Trics swell up and start turning milky, fan leaves get yellow splotches and the stems start to wither up as the buds fluff triumphantly in an effort to grab on to any passing pollen because the plant desperately wants to produce seed. By the second or third cycle the buds are just magnificent! Overall quality of the buds is helped in so many different ways by a properly executed flush/starve cycle that it is difficult to expound them to completion. Suffice to say it is very much worth a cannabis cultivator's time to nail down a good flush/starve/feed cycle.

Good luck and happy gardening!

-DM

DrunkenMessiah said:

That means all of the resources that the plant sends up to the flowers in an effort to save the seeds winds up going towards trichome production instead!

A lot of other cool things happen when you starve. Resin and oil production dramatically goes up when mosture becomes scarce. This is because up to a point the oils that cannabis produces are able to take the place of water for some tasks. Maintaining turgidity, propping up the cell structure and keeping the sap layer free-flowing are all things that oil can do when there isn't enough water around.

-DM

Click to expand...

I appreciate your observations. A lot of people get squeamish when it comes to starving, dehydrating, stressing, training, etc.

One point, though. A detail, really. What oils are you referring to that replace water in plant cell structure? What is made in the Trichome stays in the Trichome.

Anyway, thanks much for the reply.

Plant oils, nothing that is directly related to trics. This is the same oil that can be squished from hemp stems to make diesel fuel. In and of itself it has very little to do with the trics. However the oils are a more complex version of the starches and sugars in the sap layer. Due to the increased complexity these oils contain building blocks for THC that have to go through fewer conversions to get there. Being oilier doesn't make a cannabis plant more potent by default but it can make it easier for that plant to produce more trics. Weather or not it actually does so is all down to genetics and environment. Indica strains are oilier in general and I have been told by several growers that they will more readily convert this oil into THC. I've seen the same process work wonders for Sativa-doms as well though.

The starve cycle frightens a lot of growers. Yes, it stresses the plant but at this point they have already sexed and you have to seriously fuck things up to make them go hermie. Go check out the mineral hydro forums. Check in on the threads written by ICmag's resident badasses. You will see them all running some form of flush/starve/feed regime.

But it isn't for everyone. If you don't flush during flower you should at least do so during the end. Flushing out the medium and letting the girls get dry while they are still attached to their root balls does wonders for the drying/curing process. The nute vacuum in the medium draws out a lot of excess nitrates (which we want to get rid of). The stems wither and all of the sugars/starches that can make bud burn harsh get used up and go to further improve the flowers. A good flush and starve before harvest works wonders for the smoking quality of the bud and also can cut weeks out of the drying/curing time. Good luck and happy gardening!

-DM

Interesting that you mention Nitrates. Someone else I'm chatting with at this very moment said the same thing. I wonder if it's known what a chem fert plant would run the risk of holding, and therefore I run the risk of smoking.

Nitrates are highly undesirable in finished bud. That's why the colas in proper 'nug porn' pictures are never green. If a finished, cured bud is green then it wasn't harvested and handled properly. Many of the nitrates get burned off during the curing process but it is possible to give the buds a head start with a proper flush/starve right before harvest. The plant uses up the nitrates for energy and pitches many undesirable materials overboard in a bid to survive. This provides a colossal advantage for the drying/curing process.

Chem plants tend to run a higher risk of retaining nutes after harvest. With no biological activity happening in their medium it is tough to get some reverse leeching going (if you don't know, that's where nitrates and other undesirable materials go from the roots back into the medium instead of the usual vice-versa). It is certainly possible to get this to happen with a mineral-fertilized plant but it is a lot tougher than when you run organics.

Bud that contains too many nitrates fizzes and crackles when you smoke it. It has a sharp, piney, minty nasty taste that stabs at the lungs and smothers the throat. This is why many organic gardeners prefer the taste of their bud to mineral fertilized stuff. Its easier to clean the plant out of all those undesirable materials at the end when you run organics. I hope you find your niche in the world of organics, you will definitely appreciate the difference in quality of your bud. Good luck and happy gardening!

-DM

Your patient replies are not falling on deaf ears. Much appreciated. I hope I'm not the only one getting something from all of this.

There's an ever-present question about the pH of the flush. This is more for the chem fert grows, but some would say that since we are not introducing nutes into the plant, lowered pH isn't necessary. Other say that an acidic flush better dissolves / removes plant salts.

It would seem that a low salt / standard pH res would better help just through Osmosis, but wondered if you had an opinion.

In a similar vein, many flush, then go to zero light for a couple days at the end of flush. Supposedly the dark cycle is when materials move up the plant. If dark, they stay at root level where they are easier to extract. Of course there is flow from roots in the daytime also, so this concept of harvesting in the dark smelled eerily like an old wives tail, perhaps.

Thanks again.

pH for flushing has long since been a source of argument for the salt hydro guys. Mineral hydro always runs a slightly acidic pH (usually around 5.8) because this makes the chemistry in the res happen faster. The acid hurries osmosis along because that is what these guys are at the mercy of when it comes to the speed of nutrient uptake.

We organic gardeners are not so concerned. When we flush the reverse leeching is driven much more by our microbial population that it is by osmosis. This is why I've only ever flushed with ordinary pH 7 water. Osmosis is certainly still a factor for us but nothing like it is for the mineral guys. Better off just leaving the pH at something which keeps the micro-life happy (6.8)

The dark period at the end is rife with legend and wive's tales. Thing is though, I've always done it but not for the reasons you listed as those are mostly BS. Nutes are carried up the plant at all times. In fact they are sometimes carried up into the plant even more during the night. Plants are capable of growing faster at night. It takes some of their total avaliable energy to drive the process of photosynthesis. When theres no light this isn't going on. At night the plant is able to put all available energy towards growth. By drawing on sugar stores that where built up during the day cannabis will often grow more aggressively in the absence of light (up to a certain limit of course).

So why harvest after a dark period? For me harvest is all about slowly killing the plant. You do not want the act of cutting it down to be what kills it, you want it to be dead when you take it up to dry. We do this with the final flush/starve cycle and then letting the plant get dry as I have already described. During this time I shut off the lights with the plants languishing without it for up to five days! (a lot of gardeners will call BS on this number, usually an aggressively grown cannabis plant will die after 48 hours with no light. This long period of lingering comes from the fact that I grow with such strong micro-life. The fugus lingers on feeding a small life-line of retained nutes and moisture to the plant to keep it alive. This lasts until the fungal network gets too dry to operate anymore and goes dormant which takes about 5 days!)

The absence of light is just another signal to the plant that it is dying. With no light it will make no effort to conduct photosynthesis. This means it is more willing to break down its chlorophyll which means tossing most of the nitrates (exactly what we want). If the lights are on the plant is gonna continue to attempt to make more sugar to keep itself alive weather or not it has enough water and nutes to actually do so. After the first 24 hours in the dark the plant starts to panic. It much more willingly burns off the nitrates, uses up its energy reserves and draws all the good stuff out of the fan leaves and lets them drop off on their own. When harvested this way a plant is almost half way finished drying by the time you cut it down. Most of the fan leaves will have completely shriveled up and dropped off. Large, undesirable bud leaves will also sometimes shrivel. The stems will be but a fraction of the diameter that they where when alive. Any remaining vegetation should be very yellow and the buds should have lost most of their chlorophyll. When you cut a plant down prematurely the buds don't get to do this until they make it into the curing jars. This means that bud dried my way is actually pretty decent to smoke even when un-cured. (granted I still recommend at least a 6 week cure on top of the drying time anyway, its just so much nicer)

It might all sound like a lot of trouble but trust me, finishing a plant off this way has many advantages. One of the biggest ones is time. If you are impatient and want to get to smoking your buds sooner this is actually the way to go. It may seem like it takes longer because of the flush and all that time spent in the dark but in reality it is the quicker way to go about it. Good luck and happy gardening!

-DM

Good answers as expected. Thank you for your time. At some point I would like to hear more about the pre-harvest starvations you mentioned in an earlier post (different thread?)

There is enough evidence that this is a good thing that I'd like to try in my nexy grow, be it standard Hydro or with an organic flavor.

Thanks again