limegreensuit
Member
I envy those who don't have to flush.
How Long Do You Flush Before Harvest?
- Thread starter whatsupdoc
- Start date
i run flora kleen from (helps separate/release nutrient compounds from plant) GH 1 1/2 weeks before harvest and then next water(s) i use ph 6.0 water.
That's all well and good Frank... but you have to remind the kiddies that your amended soil is well balanced and not over amended.
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I've said I can taste the difference in certain organic feeding programs as a result of base nutrition.
I really believe, regardless what amount of unused amendments remain in the soil, this approach eliminates such a concern...the micro herd makes various items available for use. Water is necessary for the proper bonds to be formed and thus absorbed by roots...
Take away water, the herd dies, the proper ionic bonds at not completed, and anything in the soil is rendered useless, regardless how present it currently is.
An active deffiency in the plant is the absence of or "lock out" of a nutrient. Nutrient "lock out" is a perfect concept of presence without availability. This forces an active lock out of everything! If the plant cannot feed from the roots, it will fed from the reserves in it's leaves. This flushes the PLANT, not the medium, as most think a flush is to remove built up nutrients in the medium, which is only half the picture...
Thanks for the kind words, sir.
dank.Frank
dank.frank said:
Yes, I've noticed that most folks have a primitive sense of taste when compared to mine. You don't seem to mind a bit of non-cannabis flavor in your meds while I find it abhorrent. *shrug*
When I grow.... all you taste is cannabis, pure and simple. Most delicious flavors on earth with no background 'organic' afterflavor.
In addition to flavor, I am able to feel coatings on my tongue and throat that are not resin related.
So I'll re-state my original position... "I don't care if it's the finest peruvian flake, organic, bat guano on the planet.... if I can taste it in my cannabis it is a contaminant. End of story."
Try backing off on your amendments a bit on one or two plants sometime. Your yields will be a bit less but the quality difference in taste, feel and body reaction (who needs to be absorbing so much 'organic' nutrition through smoke??) are so worthwhile it's crazy.
Most of the time it sucks being this sensitive.... sure has made me grow some super clean meds though.
Stay Safe!
HobbyGrower
Member
I think you can get away with not flushing in soil. You'll never truly flush anything from the plant since the roots are immersed in soil and constantly feeding on broken down food. It's certainly possible but done too long and you'll pass a point of diminishing returns.
In hydro, flushing is absolutely mandatory, imo. Those who say they flush for 2 weeks and don't notice a difference aren't doing it right. You'll know when you combust properly flushed hydro.
Instead of starving my plants for the last two weeks, I wait until the plant is done and I'm ready to harvest; then use a flushing agent. Kind of like taking a snapshot. The flush begins at the point when I'm done with the cycle. The process takes between 3-6 days.
Good luck, and happy growing!
In hydro, flushing is absolutely mandatory, imo. Those who say they flush for 2 weeks and don't notice a difference aren't doing it right. You'll know when you combust properly flushed hydro.
Instead of starving my plants for the last two weeks, I wait until the plant is done and I'm ready to harvest; then use a flushing agent. Kind of like taking a snapshot. The flush begins at the point when I'm done with the cycle. The process takes between 3-6 days.
Good luck, and happy growing!
HobbyGrower said:
Hate to break it to you but.... I haven't run in to a flushing agent yet that I couldn't taste. They're disgusting. And yeah... I have a suuuuuper sensitive palate and can taste stuff most wouldn't in a million years.
Actually had eye twitches from one batch some guy grew. Only thing different was the flushing agent he used.
Stick with water and keep your funds to yourself. The single best way to improve the taste of your cannabis is to not use tap water unless it's super clean with just a bit of trace elements. I recommend R/O for everyone else.
Stay Safe!
Edit: The trick with soil is to have a light and fluffy soil mix. Never feed to much and just use plain R/O water for the last 2-3 weeks. If anything, you always want to underfeed in soil just a wee bit... not enough to cause starvation but closer to hungry than stuffed.
Organic amended soil needs to be mixed carefully or better yet composted a bit to ensure that all amendments are broken down and gone by the time the plant is 2 -3 weeks from harvest.
Best methods I've seen for this are organic amended soils that require teas for bloom. By the time the last 2-3 weeks comes around the amends are gone and you simply switch to plain water. Happy Toking!
HobbyGrower
Member
Hate to break it to you but you're in an elite group. For the rest of us that can't taste air, use a flushing agent... but not necessary in soil.
HobbyGrower said:
Hate to break it to you but.... if I can taste it, you don't want it in your body. Just because you can't taste a low level of arsenic... doesn't mean you won't die from accumulation over time. Your body doesn't need extra NPK in organic smoke.
Also hate to bring this up but it's the truth.... Most people can't tell their meds are fucked up until they actually run across clean meds for more than one baggie. Considering how few folks know how to grow clean meds, it isn't surprising that most meds are shit... health wise.
Disgusting.
Stay Safe!
sledgehammer from foxfarm has only seaweed in it. fast results in soil for me. leaves changed colors the next day.
besides that try the tidy bowl line, drop one right in the toilet. do this with confidence, its made for like 2000 flushes. you can flush a huge crop fast this way, and it turns it blue, which people love!
besides that try the tidy bowl line, drop one right in the toilet. do this with confidence, its made for like 2000 flushes. you can flush a huge crop fast this way, and it turns it blue, which people love!
Baddog40 said:
Would LOVE for this to be true... but that's not true.
Nutrient taste does NOT go away with a proper dry and cure. The flavors of the cannabis may become strong enough that you believe this... but the crap you fed the plant is still there.
Plain R/O water helps set up a lock-out condition where the plant is forced to use stored up nutrients.... since it can't get any from the soil. If you overfed enough... you probably aren't going to get it out in a month of R/O waterings. Cannabis stores extra nutes VERY well.
Stay Safe!
Who are you going to believe here?
Some guy that can taste a speck of gnat shit burning in his bud or your average joe that can't taste subtle nuances of cannabis to save his life?
I'm telling you that a good 70% or more (more in non-med states) of the cannabis being offered for sale in the U.S. (and probably the world) is unhealthy.... just from the leftover nutes. Most cases it's slight so your body only experiences a bit of a slowdown from the extra nutes. In extreme cases the continual exposure to PGR, Insecticide, nutrients and miticide residues will cause health issues... especially if you're making and eating mass concentrates.
Prohibition sucks aaaaass! It's the reason nobody has the right info about growing and clean meds.
I dare anyone to just pick 3 random samples off the street or from growers and have it tested for NPK and residues of all the shit the polluted shit the vendors are pushing these days.
I doubt you'd find much of anything but cannabis in the meds I grow.... I KNOW you'll find a lot more in your average grows.
Not everyone has taste buds for being a professional wine taster.... I would imagine very few do.
Always keep in mind that your opinion is subject to your experience. I know for a fact that I've run the gamut in this field.... with a highly sensitive palate. You would do well to listen.
Stay Safe!
Some guy that can taste a speck of gnat shit burning in his bud or your average joe that can't taste subtle nuances of cannabis to save his life?
I'm telling you that a good 70% or more (more in non-med states) of the cannabis being offered for sale in the U.S. (and probably the world) is unhealthy.... just from the leftover nutes. Most cases it's slight so your body only experiences a bit of a slowdown from the extra nutes. In extreme cases the continual exposure to PGR, Insecticide, nutrients and miticide residues will cause health issues... especially if you're making and eating mass concentrates.
Prohibition sucks aaaaass! It's the reason nobody has the right info about growing and clean meds.
I dare anyone to just pick 3 random samples off the street or from growers and have it tested for NPK and residues of all the shit the polluted shit the vendors are pushing these days.
I doubt you'd find much of anything but cannabis in the meds I grow.... I KNOW you'll find a lot more in your average grows.
Not everyone has taste buds for being a professional wine taster.... I would imagine very few do.
Always keep in mind that your opinion is subject to your experience. I know for a fact that I've run the gamut in this field.... with a highly sensitive palate. You would do well to listen.
Stay Safe!
whatsupdoc
Member
It's all good. There's room for all opinions on this issue.
Pre harvest flushing is a controversial topic. Flushing is supposed to improve taste of the final bud by either giving only pure water, clearing solutions or extensive flushing for the last 7-14 days of flowering. While many growers claim a positive effect, others deny any positive influence or even suggest reduced yield and quality.
The theory of pre harvest flushing is to remove nutrients from the grow medium/root zone. A lack of nutrients creates a deficiency, forcing the plant to translocate and use up its internal nutrient compounds.
Nutrient fundamentals and uptake:
Until recently it was common thought that all nutrients are absorbed by plant roots as ions of mineral elements. However in newer studies more and more evidence emerged that additionally plant roots are capable of taking up complex organic molecules like amino acids directly thus bypassing the mineralization process.
The major nutrient uptake processes are:
1) Active transport mechanism into root hairs (the plant has to put energy in it, ATP driven) which is selective to some degree. This is one way the plant (being immobile) can adjust to the environment.
2) Passive transport (diffusion) through symplast to endodermis.
http://www.biol.sc.edu/courses/bio102/f99-3637.html
http://www.hort.wisc.edu/cran/Publications/2001 Proceedings/min_nutr.pdf
The claim only ‘chemical’ ferted plants need to be flushed should be taken with a grain of salt. Organic and synthetic ferted plants take up mineral ions alike, probably to a different degree though. Many influences play key roles in the taste and flavor of the final bud, like the nutrition balance and strength throughout the entire life cycle of the plant, the drying and curing process and other environmental conditions.
3) Active transport mechanism of organic molecules into root hairs via endocytosis.
http://acd.ucar.edu/~eholland/encyc6.html
Here is a simplified overview of nutrient functions:
Nitrogen is needed to build chlorophyll, amino acids, and proteins. Phosphorus is necessary for photosynthesis and other growth processes. Potassium is utilized to form sugar and starch and to activate enzymes. Magnesium also plays a role in activating enzymes and is part of chlorophyll. Calcium is used during cell growth and division and is part of the cell wall. Sulfur is part of amino acids and proteins.
Plants also require trace elements, which include boron, chlorine, copper, iron, manganese, sodium, zinc, molybdenum, nickel, cobalt, and silicon.
Copper, iron, and manganese are used in photosynthesis. Molybdenum, nickel, and cobalt are necessary for the movement of nitrogen in the plant. Boron is important for reproduction, while chlorine stimulates root growth and development. Sodium benefits the movement of water within the plant and zinc is neeeded for enzymes and used in auxins (organic plant hormones). Finally, silicon helps to build tough cell walls for better heat and drought tolerance.
http://www.sidwell.edu
You can get an idea from this how closely all the essential elements are involved in the many metabolic processes within the plant, often relying on each other.
Nutrient movement and mobility inside the plant:
Besides endocytosis, there are two major pathways inside the plant, the xylem and the phloem. When water and minerals are absorbed by plant roots, these substances must be transported up to the plant's stems and leaves for photosynthesis and further metabolic processes. This upward transport happens in the xylem. While the xylem is able to transport organic compounds, the phloem is much more adapted to do so.
The organic compounds thus originating in the leaves have to be moved throughout the plant, upwards and downwards, to where they are needed. This transport happens in the phloem. Compounds that are moving through the phloem are mostly:
Sugars as sugary saps, organic nitrogen compounds (amino acids and amides, ureides and legumes), hormones and proteins.
http://www.sirinet.net
Not all nutrient compounds are moveable within the plant.
1) N, P, K, Mg and S are considered mobile: they can move up and down the plant in both xylem and phloem.
Deficiency appears on old leaves first.
2) Ca, Fe, Zn, Mo, B, Cu, Mn are considered immobile: they only move up the plant in the xylem.
Deficiency appears on new leaves first.
http://generalhorticulture.tamu.edu
Storage organelles:
Salts and organic metabolites can be stored in storage organelles. The most important storage organelle is the vacuole, which can contribute up to 90% of the cell volume. The majority of compounds found in the vacuole are sugars, polysaccharides, organic acids and proteins though.
http://jeb.biologists.org.pdf
Translocation:
Now that the basics are explained, we can take a look at the translocation process. It should be already clear that only mobile elements can be translocated through the phloem. Immobile elements cant be translocated and are not more available to the plant for further metabolic processes and new plant growth.
Since flushing (in theory) induces a nutrient deficiency in the rootzone, the translocation process aids in the plants survival. Translocation is transportation of assimilates through the phloem from source (a net exporter of assimilate) to sink (a net importer of assimilate). Sources are mostly mature fan leaves and sinks are mostly apical meristems, lateral meristem, fruit, seed and developing leaves etc.
You can see this by the yellowing and later dying of the mature fan leaves from the second day on after flushing started. Developing leaves, bud leaves and calyxes don’t serve as sources, they are sinks. Changes in those plant parts are due to the deficient immobile elements which start to indicate on new growth first.
Unfortunately, several metabolic processes are unable to take place anymore since other elements needed are no longer available (the immobile ones). This includes processes where nitrogen and phosphorus, which have likely the most impact on taste, are involved.
For example nitrogen: usually plants use nitrogen to form plant proteins. Enzyme systems rapidly reduce nitrate-N (NO3-) to compounds that are used to build amino-nitrogen which is the basis for amino acids. Amino acids are building blocks for proteins, most of them are plant enzymes responsible for all the chemical changes important for plant growth.
Sulfur and calcium among others have major roles in production and activating of proteins, thereby decreasing nitrate within the plant. Excess nitrate within the plant may result from unbalanced nutrition rather than an excess of nitrogen.
http://muextension.missouri.edu
Summary:
Preharvest flushing puts the plant(s) under serious stress. The plant has to deal with nutrient deficiencies in a very important part of its cycle. Strong changes in the amount of dissolved substances in the root-zone stress the roots, possibly to the point of direct physical damage to them. Many immobile elements are no more available for further metabolic processes. We are loosing the fan leaves and damage will show likely on new growth as well.
The grower should react in an educated way to the plant needs. Excessive, deficient or unbalanced levels should be avoided regardless the nutrient source. Nutrient levels should be gradually adjusted to the lesser needs in later flowering. Stress factors should be limited as far as possible. If that is accomplished throughout the entire life cycle, there shouldn’t be any excessive nutrient compounds in the plants tissue. It doesn’t sound likely to the author that you can correct growing errors (significant lower mobile nutrient compound levels) with preharvest flushing.
Drying and curing (when done right) on the other hand have proved (In many studies) to have a major impact on taste and flavour, by breaking down chlorophylls and converting starches into sugars. Most attributes blamed on unflushed buds may be the result of unbalanced nutrition and/or overfert and unproper drying/curing.
The theory of pre harvest flushing is to remove nutrients from the grow medium/root zone. A lack of nutrients creates a deficiency, forcing the plant to translocate and use up its internal nutrient compounds.
Nutrient fundamentals and uptake:
Until recently it was common thought that all nutrients are absorbed by plant roots as ions of mineral elements. However in newer studies more and more evidence emerged that additionally plant roots are capable of taking up complex organic molecules like amino acids directly thus bypassing the mineralization process.
The major nutrient uptake processes are:
1) Active transport mechanism into root hairs (the plant has to put energy in it, ATP driven) which is selective to some degree. This is one way the plant (being immobile) can adjust to the environment.
2) Passive transport (diffusion) through symplast to endodermis.
http://www.biol.sc.edu/courses/bio102/f99-3637.html
http://www.hort.wisc.edu/cran/Publications/2001 Proceedings/min_nutr.pdf
The claim only ‘chemical’ ferted plants need to be flushed should be taken with a grain of salt. Organic and synthetic ferted plants take up mineral ions alike, probably to a different degree though. Many influences play key roles in the taste and flavor of the final bud, like the nutrition balance and strength throughout the entire life cycle of the plant, the drying and curing process and other environmental conditions.
3) Active transport mechanism of organic molecules into root hairs via endocytosis.
http://acd.ucar.edu/~eholland/encyc6.html
Here is a simplified overview of nutrient functions:
Nitrogen is needed to build chlorophyll, amino acids, and proteins. Phosphorus is necessary for photosynthesis and other growth processes. Potassium is utilized to form sugar and starch and to activate enzymes. Magnesium also plays a role in activating enzymes and is part of chlorophyll. Calcium is used during cell growth and division and is part of the cell wall. Sulfur is part of amino acids and proteins.
Plants also require trace elements, which include boron, chlorine, copper, iron, manganese, sodium, zinc, molybdenum, nickel, cobalt, and silicon.
Copper, iron, and manganese are used in photosynthesis. Molybdenum, nickel, and cobalt are necessary for the movement of nitrogen in the plant. Boron is important for reproduction, while chlorine stimulates root growth and development. Sodium benefits the movement of water within the plant and zinc is neeeded for enzymes and used in auxins (organic plant hormones). Finally, silicon helps to build tough cell walls for better heat and drought tolerance.
http://www.sidwell.edu
You can get an idea from this how closely all the essential elements are involved in the many metabolic processes within the plant, often relying on each other.
Nutrient movement and mobility inside the plant:
Besides endocytosis, there are two major pathways inside the plant, the xylem and the phloem. When water and minerals are absorbed by plant roots, these substances must be transported up to the plant's stems and leaves for photosynthesis and further metabolic processes. This upward transport happens in the xylem. While the xylem is able to transport organic compounds, the phloem is much more adapted to do so.
The organic compounds thus originating in the leaves have to be moved throughout the plant, upwards and downwards, to where they are needed. This transport happens in the phloem. Compounds that are moving through the phloem are mostly:
Sugars as sugary saps, organic nitrogen compounds (amino acids and amides, ureides and legumes), hormones and proteins.
http://www.sirinet.net
Not all nutrient compounds are moveable within the plant.
1) N, P, K, Mg and S are considered mobile: they can move up and down the plant in both xylem and phloem.
Deficiency appears on old leaves first.
2) Ca, Fe, Zn, Mo, B, Cu, Mn are considered immobile: they only move up the plant in the xylem.
Deficiency appears on new leaves first.
http://generalhorticulture.tamu.edu
Storage organelles:
Salts and organic metabolites can be stored in storage organelles. The most important storage organelle is the vacuole, which can contribute up to 90% of the cell volume. The majority of compounds found in the vacuole are sugars, polysaccharides, organic acids and proteins though.
http://jeb.biologists.org.pdf
Translocation:
Now that the basics are explained, we can take a look at the translocation process. It should be already clear that only mobile elements can be translocated through the phloem. Immobile elements cant be translocated and are not more available to the plant for further metabolic processes and new plant growth.
Since flushing (in theory) induces a nutrient deficiency in the rootzone, the translocation process aids in the plants survival. Translocation is transportation of assimilates through the phloem from source (a net exporter of assimilate) to sink (a net importer of assimilate). Sources are mostly mature fan leaves and sinks are mostly apical meristems, lateral meristem, fruit, seed and developing leaves etc.
You can see this by the yellowing and later dying of the mature fan leaves from the second day on after flushing started. Developing leaves, bud leaves and calyxes don’t serve as sources, they are sinks. Changes in those plant parts are due to the deficient immobile elements which start to indicate on new growth first.
Unfortunately, several metabolic processes are unable to take place anymore since other elements needed are no longer available (the immobile ones). This includes processes where nitrogen and phosphorus, which have likely the most impact on taste, are involved.
For example nitrogen: usually plants use nitrogen to form plant proteins. Enzyme systems rapidly reduce nitrate-N (NO3-) to compounds that are used to build amino-nitrogen which is the basis for amino acids. Amino acids are building blocks for proteins, most of them are plant enzymes responsible for all the chemical changes important for plant growth.
Sulfur and calcium among others have major roles in production and activating of proteins, thereby decreasing nitrate within the plant. Excess nitrate within the plant may result from unbalanced nutrition rather than an excess of nitrogen.
http://muextension.missouri.edu
Summary:
Preharvest flushing puts the plant(s) under serious stress. The plant has to deal with nutrient deficiencies in a very important part of its cycle. Strong changes in the amount of dissolved substances in the root-zone stress the roots, possibly to the point of direct physical damage to them. Many immobile elements are no more available for further metabolic processes. We are loosing the fan leaves and damage will show likely on new growth as well.
The grower should react in an educated way to the plant needs. Excessive, deficient or unbalanced levels should be avoided regardless the nutrient source. Nutrient levels should be gradually adjusted to the lesser needs in later flowering. Stress factors should be limited as far as possible. If that is accomplished throughout the entire life cycle, there shouldn’t be any excessive nutrient compounds in the plants tissue. It doesn’t sound likely to the author that you can correct growing errors (significant lower mobile nutrient compound levels) with preharvest flushing.
Drying and curing (when done right) on the other hand have proved (In many studies) to have a major impact on taste and flavour, by breaking down chlorophylls and converting starches into sugars. Most attributes blamed on unflushed buds may be the result of unbalanced nutrition and/or overfert and unproper drying/curing.
Basically all that I found relevant from that 420 Magazine article was the above section. The author then goes on to state that this results in flushing shutting down protein production which somehow affects taste negatively. My impression is that the author of the article pretty much pulled the conclusion out of his ass.
I don't believe in flushing in my own grows (organic soil(less)). Conceptually flushing just doesn't make sense. This said, since a plant a few weeks away from harvest is close to shutting down metabolically, I don't see the point in applying insoluble organic fertilizers during the last few weeks.
I've never used conventional fertilizers and don't have an opinion about flushing when using them.
Pine
I've never used conventional fertilizers and don't have an opinion about flushing when using them.
Pine
Should we coin a new term or something?
Flushing: A (usually emergency) procedure involving putting excessive amounts of water through the medium to dilute whatever nutrients/etc are in the medium.
Timed Flush: A period of regular plain water feedings prior to harvest.
I've had PLENTY of meds that folks thought was clean and great..... that was actually really disgusting. What can you say to someone who doesn't have the experience to know the difference??
Stay Safe!
Flushing: A (usually emergency) procedure involving putting excessive amounts of water through the medium to dilute whatever nutrients/etc are in the medium.
Timed Flush: A period of regular plain water feedings prior to harvest.
I've had PLENTY of meds that folks thought was clean and great..... that was actually really disgusting. What can you say to someone who doesn't have the experience to know the difference??
Stay Safe!
Probably we should because people refer to "flushing" as both, which creates confusion.
Anyone that grows for themselves should do some experimenting. If they can't tell the difference, they should do whatever is the easiest-cheapest. I've tried the excessive water thing and I think it is pointless.
I have enough concerns about other peoples "meds" that I won't even smoke them - not even a puff. Just reading this site it is evident that growers do some pretty suspect-questionable things just to be able to produce a crop, or to be able to produce a higher yielding crop. A lack of a proper "timed flush" is the least of my concerns.
Pine
OGShush
Member
I got to see a lot of lab test results and I think people would be shocked by the amount of nutrient residue in dried buds. Almost every result I saw had at least 10ppm of fertilizer residue. The sales rep for the testing facility said anything under 25 was a safe amount, but he also said the lab technician disagreed and said any residue was completely unacceptable.
That being said, I flushed for about two and a half weeks this last time. My chem is still drying out, but the trainwreck has been curing a few weeks and the smoke is fantastic. The only thing I did different with the chem was I fed it a little bit of mg and sulfur up until the last week.
F
Fastcast
I have never flushed any plant including my veggies.
