When do you P/K boost?

[GF-Z]

If you want to try PK boosters you can add them for a week, 3 weeks before harvest.

For most strains that means feeding them at flowering wk 5 or 6



I always use it and feel i get a much better yield with it. I really notice an increased rate of calyx/pistil formation a week after use. Aren't P and K primary required nutrients essential in flowering?

More of a forum myth is calmag surely

Potassium is definately required, but phosphorous is mainly required for seed production. Prof. Bruce Bugbee has videos on YT explaining it in details. Phosphorus is necessery but not in amounts most growers put it into. Plant usually stores it and then forces upwards when flowering stage ir reached, to produce strong and healthy seeds which would survive.
Thaths when Ive bought some hemp seed meal protein, Ive found it has P amounts of almost 500% daily requirements for human consumption.
So this proves the fact that indeed plant store P in the seeds.

 

[William76]

U can definitely see the difference in a plant with a pk boost and a plant without,if u were to do a side by side grow.76

 

[Old Uncle Ben]

Potassium is definately required, but phosphorous is mainly required for seed production. Prof. Bruce Bugbee has videos on YT explaining it in details. Phosphorus is necessery but not in amounts most growers put it into. Plant usually stores it and then forces upwards when flowering stage ir reached, to produce strong and healthy seeds which would survive.
Thaths when Ive bought some hemp seed meal protein, Ive found it has P amounts of almost 500% daily requirements for human consumption.
So this proves the fact that indeed plant store P in the seeds.

Kicker is, how much is required to support the plant during its different stages of life, juvenile thru harvest? Here's a ditty I posted years ago that is still posted in some forums FWIW.

The never ending abuse of Phosphorous to enhance flowering

A common mistake for growers when they reach the flowering stage is to start hitting the plants with a high P fert like a 10‑50‑10, continuing to use this blend exclusively, and when their plants start experiencing a deficit of N, Ca, Mg or micros as reflected by the dropping of lower leaves and chlorosis, they wonder why. Plants flower as a response to long nights (or chronological age if equatorial), not because of food blends high in P (or K). A ratio of 10‑30‑10 is WAY too high in P. The plant will only take what it needs and compete for other elements that may be more important at the time.

You may have heard that too much N can inhibit flowering. No question about it, exclusive use of a plant food that is rich in N such as blood meal, a 5‑1‑1 blend, or ammonium nitrate/sulfate may inhibit flowering especially if the phosphorous level is low, but most balanced blends have sufficient amount of P to do the job. The question is ‑ "how much P is enough to support a good flowering response and still retain my leaves?"

Manufacturers/horticulturists will give you element analysis and what effect the elements have on plant growth, but remember this does not necessarily mean you will get better yields. Using a high P fert exclusively during flowering can actually work against you due to impending leaf drop. It's an abundant amount of healthy leaves going into 12/12 and maintaining their health until harvest that produces a lot of bud, not high P, or low N foods.

I rotate fertilizer blends as the plant *requires* them, not because it is "the thing to do." For example, when your plants are going thru the stretch phase during early flowering, they may need more N, especially if you're getting some yellowing in the lower leaves. Give up the cannabis paradigms and give them what they need. You may want to return to a mild high P fert when the stretch ends, maintaining the foliage in a healthy state of growth until harvest for maximum yields. A 1‑3‑2 blend such as Peter's Pro Blossom Booster, 10‑30‑20, is a good choice because of several factors ‑ it is higher in nitrate N and Mg and has a good micro package. It is sold under the Jack's Classic label.

There are many foods I stock in my toolbox. Dyna-Gro is another excellent brand. I use a lot of their Foliage Pro - 9-3-6.

Stay away from cannabis specific foods. They market unsuspecting newbies who don’t yet have a handle on plant nutrition and soil chemistry.

Uncle Ben

 

[Hiddenjems]

Your unhealthy leaf issues is why you should never P/K boost. That's another forum myth hefted on to the newbie community by the cannabis specific foods industry who's main goal is to make a buck.

It's leaves that produce bud, not some silly P/K "boost" food. You boosted alright - premature leaf necrosis.

Witness my use of balanced NPK foods from start to finish. It's only natural.

View attachment 18926791

View attachment 18926792

UB

While I don’t use your specific nutrient line I have noticed little if any difference in overall yield between runs with straight Lucas formula the whole way, and trying to tailor the nutes to growth phase. All I did with Lucas was increase concentration til week6/7 then raise back down.


What I have noticed with heavy training and nutrient manipulation is the ability to change the ratio of larf to a bud, but not really total flower yield.

 

[Hiddenjems]

Kicker is, how much is required to support the plant during its different stages of life, juvenile thru harvest? Here's a ditty I posted years ago that is still posted in some forums FWIW.

The never ending abuse of Phosphorous to enhance flowering

A common mistake for growers when they reach the flowering stage is to start hitting the plants with a high P fert like a 10‑50‑10, continuing to use this blend exclusively, and when their plants start experiencing a deficit of N, Ca, Mg or micros as reflected by the dropping of lower leaves and chlorosis, they wonder why. Plants flower as a response to long nights (or chronological age if equatorial), not because of food blends high in P (or K). A ratio of 10‑30‑10 is WAY too high in P. The plant will only take what it needs and compete for other elements that may be more important at the time.

You may have heard that too much N can inhibit flowering. No question about it, exclusive use of a plant food that is rich in N such as blood meal, a 5‑1‑1 blend, or ammonium nitrate/sulfate may inhibit flowering especially if the phosphorous level is low, but most balanced blends have sufficient amount of P to do the job. The question is ‑ "how much P is enough to support a good flowering response and still retain my leaves?"

Manufacturers/horticulturists will give you element analysis and what effect the elements have on plant growth, but remember this does not necessarily mean you will get better yields. Using a high P fert exclusively during flowering can actually work against you due to impending leaf drop. It's an abundant amount of healthy leaves going into 12/12 and maintaining their health until harvest that produces a lot of bud, not high P, or low N foods.

I rotate fertilizer blends as the plant *requires* them, not because it is "the thing to do." For example, when your plants are going thru the stretch phase during early flowering, they may need more N, especially if you're getting some yellowing in the lower leaves. Give up the cannabis paradigms and give them what they need. You may want to return to a mild high P fert when the stretch ends, maintaining the foliage in a healthy state of growth until harvest for maximum yields. A 1‑3‑2 blend such as Peter's Pro Blossom Booster, 10‑30‑20, is a good choice because of several factors ‑ it is higher in nitrate N and Mg and has a good micro package. It is sold under the Jack's Classic label.

There are many foods I stock in my toolbox. Dyna-Gro is another excellent brand. I use a lot of their Foliage Pro - 9-3-6.

Stay away from cannabis specific foods. They market unsuspecting newbies who don’t yet have a handle on plant nutrition and soil chemistry.

Uncle Ben

I’ve seen people kill plants for lack of calcium because they’re afraid of calcium nitrate in flower.

 

[I Care]

This is in order or application and introduction to nutrient regimen.



FOX FARMS GROW BIG 6-4-4
I watered the clone into a 600cc the day I brought I home.
Strawberry Fields Soil and 2 TSP/Gallon Ever, continued every watering.

FOX FARMS Cultuvation Nation 5-0-1

FOX FARMS Cal-MAG

^^^^^^^^
Got these as a supplement because I saw decifiency.
Was root bounding… this shocked it.
It recovered and I used this stuff lightly 2-3ml/gallon every few waterings.



GENERAL ORGANICS BioThrive Bloom 2-4-4
Introduced two weeks before flower and repotting.
1tsp This and 1Tsp GrowBig and 2-3ml CalMag

THIS WEEK
Molasses (maybe 1-0-5 ) 1TSP every watering.

and ALASKA MORBLOOM 0-10-10 2TSP/Gal (too much, I know now)
Reduced to 1/2TSP/Gal

And NEPTUNE’S SEAWEED. 0-0-1 at 1TSP/Gallon

Here is a piece of graph Paper!

The clicker of the pen points at the the solution I have diluted into* almost 4 Gallons or **approximately to 3ML a Liter


I have a headache!

 

[I Care]

The only thing I couldn’t get in town was the GENERAL ORGANICS BioThrive Bloom 2-4-4

 

[I Care]

She is drinking!!! Fast!

 

[CharlesU Farley]

You guys tend to over think this food thingie making it so confusing, resulting in subpar results. You might fail due to nutrient antagonism issues while blaming your problems on lame stuff like pH imbalances, lack of Mg, Ca, etc. Cannabis is quite pH tolerant when it comes to processing salts via the roots. I never worry about it. I throw together a bulk load of soil with whatever I have stockpiled which might include washed coarse sand piled outdoors.

Just telling it like it is based on over 20 years of observations and postings.

Uncle Ben

Truer words have never been posted on this forum. People freak out so much over fertilizer, lights, VPD, etc., they forget to actually observe the plant and miss the subtle signs it's trying to show them.

I have never measured pH, PAR, EC, or anything else people are so enamored of these days. Yet I've managed to produce this from 25 year-old NL seed, grown in cheap ass Miracle-Gro potting soil and fertilized with Peter's 20/20/20. And to keep this OT, I've _never_ done a fertilizer boost, other than giving a bit of extra Peters for the first couple of weeks when I initiate flowering, because of stretch:

 

[I Care]

gotcha.
So it’s so much easier to just feed a perfectly balanced offering.
Then if you see something off, know that there’s no NPK issue. Knowing that another nutrient is out of balance.

So I grow with “veg” nutes. Spot a nitrogen induced deficiency. Introduce Pt3 and CalMag because of the calcium and magnesium deficiencies when I refer to the chart. What I should have done was to give the plant less nitrogen, or actually have given more PK; because the issue was in the N and not in the P,K,Ca,Mg. It’s because I was giving 6-4-4.

So if I started a 1PT 2-4-4, 1PT 6-4-4, with1/2pt 5-0-1 and and 1/2pt 1-0-0 @ 3tsp/gallon. Then the problem that is present in the photo that uncle Ben commented about PKs before I added them. My problem is that I started to whack out the N, again, with the 5-0-1 and the 1-0-0.

Then the lesson is that my first issue was nitrogen. Then I add calcium and magnesium and more nitrogen because the chart says that it’s CaMg, which is because of the nitrogen. Promoting the issue instead of reducing the N that is provided in grow micros.

So then after fighting with the grow nutes, those of us that are slightly stupid don’t ever get right until weeks after giving the “flower” nutes and pulling “veg”. We give PK boost and finally the soil has become a balanced media and your puffage is ready for harvest. You get the cannabinoids but you just spent extra money and get a reduced yield all due to the nitrogen in the first place. I should say; I spent extra money, just to get the same exact bud but hurt the yields as I balance out the weeks(months in my case) of nitrogen rich fertilizer.


Wow! You guys really know how to party!

So every problem everyone has ever had with bottle nutes has stemmed from the nitrogen accumulation through the weeks of veg. Instead of starting 1 to 1 (Veg to Flower) until the stretch has subsided, the deficiency charts lead us to go and treat deficiencies with bottle nutes that contain the stuff or plants aren’t eating because of the nitrogen, all while adding even more nitrogen!!!



.

From @Creeperpark to @CharlesU Farley and everybody in between

Collection of growers in this fellowship really equates to life changing stuff.

 

[Ca++]

Tissue Analysis

The PK accumulation rate is fairly consistent, except for a steep climb through the 4th week of flower.
Some approach this by raising PK a little, over a slightly longer period.
Others increase PK a lot, for just a few days, starting week 3. The idea here, is if the week came early, you catch the tail end of it. Otherwise, you are getting it in there before it's needed. The plant can store them, and move them about when it needs to.
P&K are mobile, and are stored in leaves throughout veg, for use in bloom. This means your defoliation program has an influence on where the plant gets the PK from. If you have stripped the plant bare, it's more likely to respond to you giving it the PK, it can no longer get from the older foliage.

Most feeds are stacked with P, and so it doesn't need a boost. K has been shown as quite useless in many tests. Only really serving to control water movement. Though that ties directly to CO2 intake, so it can't be ignored.

Most balanced feeds have what is needed. Even an all-in-one garden food, if you let the plant/compost store the PK through veg, and don't then take all the stores away.
I don't see real gains from adding them, unless the plant actually asks. Which is rare. What I see more, is premature browning of the white hairs, which is tied to one of the two, but I can't be certain which. PK can fry a plant overnight, using bottle recommendations. P gives weed that chemical taste we find everywhere, and K can make sparks. They can be useful, but are really advanced gardening tools. One's I hope not to need. As the goal is to find a base feed that works, so you don't need lots of bottles.

My recent use of PK has been turning veg food to bloom food, and also correcting a whole range of new bases I was trying. Oddly, with all the tools, I ended up formulating what seemed to work best, then finding my usual Ionic was the closest base feed I could find to ideal. Or for me at least, as I just want a bottle of something. Not lots of bottles, to act like a mad scientist.

 

[mexweed]

Take a scroll through the cheap nutrients for commercial and home grows thread, there are tissue sample tests, which I think the pic above may be from, to back up what it recommends, it may be better suited for what you are trying to do than mixing and matching bottles

 

[Ca++]

Take a scroll through the cheap nutrients for commercial and home grows thread, there are tissue sample tests, which I think the pic above may be from, to back up what it recommends, it may be better suited for what you are trying to do than mixing and matching bottles

This thread https://www.icmag.com/threads/cheap-nutrient-line-for-commercial-and-home-grows.377753/
I did indeed get it there. Bill got it from Agricen

 

[I Care]

I haven’t left the forum except to shit, shower and smoke my hand rolled tobacco on the porch. Lol

One of my many great mentors, really tried to show me the way in life. He told me “Questions will get you around the world.” I’ve made it through 11 time zones so far.

That mad scientist comment actually did make me laugh a lot!
I know that’s what it looks like I’m doing. I got all of this for the various micros, trying to get the most complete GMO I can possibly get. We really don’t do this stuff for anybody else unless it can maybe improve their lives. I smoked some strawnanna that had 32% total with 1%CBD and it seriously made it so I could recover from some trauma and get some sleep at night. Stuff was a serious medicine for recovery. I could have used more of that to help me in my life but having that puffage for a week made a huge difference in my life! One of the guys at the shop, who was the one to disappoint me with the news that there’s no certainty it will return; he said the it was the most helpful medicine he has ever had for his turrets syndrome.

I am a pipe smoker, I don’t like the whole smoked out feeling of having to smoke some big dog leg to get high and then end up smelling like weed and paper everywhere I go. Unless it’s like my birthday or something, then I need to smoke a Dutch MasterBlue Palma. I also don’t really like processed forms of anything in my personal experience. It just takes the natural thrill out of life when I over do it with concentrates.

The thing that really blows my mind, is that this thread leads me to realize I had nutrients stacked up in the soil, nitrogen in base nutes causes a deficiency after 6 weeks. Which would have been resolved with just cutting in PK after 4 weeks of veg. And it dawns on me that this strain that contains decades old genetics from growers like Mr Farley. It’s not some unstable concoction of unstable concoctions.

I have had the epiphany that base “veg” nutes that have N greater than P and K will eventually cause deficiencies after the roots have become well established in small pots. Mr Farleys keys to success, we don’t stray very far from NPK 1-1-1 the whole way through the grow. And then everything else that you guys have to offer in that reply. It makes me realize we can probably get away with almost anything if we maintain that balance very close to 1-1-1 until we have made it through the stretch with healthy foliage.

So if we keep things balanced through the stretch we may be able to get away with almost anything. Then at the end, whether intention is to bulk up, fluff out, produce sugary resins, or to increase certain cannabinoids, we can change what we are doing to focus on whatever profile we are in pursuit of,

Maybe the reality is it doesn’t matter what you use, could be piss and vinegar if the NPKs balance out. You won’t have some spooky deficiency being mislead by the “veg” and “bloom” scam that you guys are preaching against here.

My problem that I had was nitrogen being above the limit. I didn’t need PK I needed less nitrogen, but the base nutrients and macro add up to heavier on the nitrates. Which meant I needed to cut in the PK to promote healthy growth with a 1-1-1. Now I’m balancing the soil back out with lower nitrogen feeding. Will do that until these gallon jugs I have mixed have cut back down to a gentle feed. And then I will find that 1-1-1 ratio like a mad scientist with what I’ve got and see if I think it comes out as good to puff as the packaged up GMO I bought from a dispensary 32% Cannabanoids. The stuff I was puffing in a Dutch Master on my birthday this year.


You guys are seriously talented, that’s why I’m listening to you, expressing agreement and learning from every single on of you coming to this thread to show me the way. My problem now is I have payed for nutrients I need to burn through, but if I end up with some puff that cures up into something that blows us away. It will be hard to want to grow anything different or to shelf these nutrients I bought before I use it all up.

 

[I Care]

I want to clarify this into a conclusion about the P/K question you guys have answered.

Base “veg” nutrients such as the Grow Big I am using are not balanced nutrients. 6-4-4 leads to nitrogen build up in potted plants. I almost killed my plants because I saw what looked like Calcium and Magnesium deficiency in week 6 of vegetation. I almost poisoned my plant to death when I added Calcium and Magnesium because they had even more nitrogen.

Now the same thing but not as serious happens when I switch to flower. I had a healthy and beautiful plant using “grow” 6-4-4 and “bloom” 2-4-4 before I once again introduced nitrogen that contradicts the idea of having perfectly balanced nutrients. Even misleading one of the well known members with 40 years of experience to think that I had boosted before I had even asked about it.

N can cause deficiency in Ca and Mg.

What benefits one may experience from P/K boosters is actually the result of our media finally balancing out after the first weeks(months) of abuse with Nitrates.


Keep NPKs evenly available at appropriate concentration. The plant will use it how it needs it to serve its life purpose of providing you delicious fruits.

 

[Old Uncle Ben]

..... My problem now is I have payed for nutrients I need to burn through, .....

I rest my case.

Base “veg” nutrients such as the Grow Big I am using are not balanced nutrients. 6-4-4 leads to nitrogen build up in potted plants.

1. It is "balanced" and 2. does not lead to N build up, whatever that means. N salts are quickly leached out with watering, another benny of using a slow release food like Osmocote Indoor-Outdoor Plus.

Wanna see some high N foods, albeit slow release? Here's a 10 month I used.

Remember, cannabis is nothing more than a flowering FOLIAGE plant. Contrary to the marketing hype and na·ive·té of noobs who don't question marketing BS, nitrogen is not a dirty word.

I almost killed my plants because I saw what looked like Calcium and Magnesium deficiency in week 6 of vegetation. I almost poisoned my plant to death when I added Calcium and Magnesium because they had even more nitrogen.

Really? Show me some pix and I can nail the issues.

I'm glad my plants can't read. :lol:

So.....with every new crop of newbies we have the same old same old - they don't concentrate their efforts on what really counts - production AND maintenance of a heavy, thick root mass and dense foliage canopy. Where do you think fruit/flowers come from, a bottle of cannabis rocket fuel? Folks, that's where the rubber meets the road, and ENDS.

Let's go back 22 years with some old genetics and a crude camera - 2001. I started heavy with organics, high N via blood meal.

Nov, 22, 2019. My 4 main cola method experiment, a Bros. Grimm In-Out plant. Old analog camera. Notice the dark green, healthy leaves. That's production. Speaking of hype, "HPS needs a MH for the blues or you can't grow good pot". Bullshit, my first garden of 6 large plants crammed together was grown exclusively under one 600W HPS. I took this 4 main cola plant outdoors for the shot.

Want N? 35-5-10. Can't remember if I used it growing pot. Maybe, maybe not.



Bottom line, you have to make roots, lots of them. And a cheap off the shelf Walmart fertilizer will work fine for soil grows. I only trust Dyna-Gro foods for water culture and foliar feeding.



^ Those images are from rootballs that were not treated to root pruning systems. Many years ago I switched over to such systems beginning with Griffin's Root Spin Out. I now use rootmaker.com products and MicroKote. https://overgrow.com/t/how-can-i-use-spin-out-for-chemical-root-pruning/258

So, do yourself a favor, get off the P/K kick and other newbie cheese, learn what makes a plant tick, and focus on roots and leaves. The bud will come.

Uncle Ben

 

[Old Uncle Ben]

Tissue Analysis

The PK accumulation rate is fairly consistent, except for a steep climb through the 4th week of flower.
Some approach this by raising PK a little, over a slightly longer period.

Need more info before I consider that a valid position. What were they fed? NPK values please? I mean, if you're feeding the plant a 0-4-4 then the tissue analysis will show a high internal P and/or K PPM. Being there always seems to be relevant factors missing in posts like this based on one's agenda, I have to ask. Most times I don't bother, got bigger fish to fry. This is important to the discussion.

The N source is shown as NH4, ammonical, which is a lame representation of actual N. Plant roots can absorb an ammonical salt such as ammonium sulfate but not pure urea for example. FWIW, I use the hell outta ammonium sulfate in bulk, mainly for my turf, BUT, if I need a hit of N to back off some yellowing leaves in weed then I might drop a pinch in a gallon of rain water for my cannabis faves, soil culture.

In a nutshell, nutrient uptake is a function of osmotic pressure across the root gradient initiated by transpiration which reduces plant tissue turgor pressure, creating a vacuum if you will at the roots. I may not have articulated this too well but you get what I mean.

Uncle Ben

 

[Old Uncle Ben]

Of course! You would think it's super easy to just answer a question, without being patronising and demeaning to the other person. But it seems to be a challenge for people with low self esteem lol.

So "they", you, answered The Question, eh? Blind leading the blind, witness your reply "People who use PK usually apply it on weeks 4-5-6". Should they dare post a whole plant or garden, 90% of their plants look like crap with yellowing leaves and the bottom defoliated, another forum drill steeped in non-botanical Herd stupidity.

Learn what makes a plant tick people. You don't need feel good baloney, You need some hard facts based on botany.

I participate in other gardening forums, some on Facebook. Folks who don't know squat will answer a question just to pop off to be heard/seen, posing as knowledgeable. Don't know how many times I've seen an answer and they have no experience when you ask for proof - "pix or it doesn't exist".

Speaking of conjecture, my self esteem is just fine, thank you very much.

Uncle Ben

 

[Ca++]

Need more info before I consider that a valid position. What were they fed? NPK values please? I mean, if you're feeding the plant a 0-4-4 then the tissue analysis will show a high internal P and/or K PPM. Being there always seems to be relevant factors missing in posts like this based on one's agenda, I have to ask. Most times I don't bother, got bigger fish to fry. This is important to the discussion.

The N source is shown as NH4, ammonical, which is a lame representation of actual N. Plant roots can absorb an ammonical salt such as ammonium sulfate but not pure urea for example. FWIW, I use the hell outta ammonium sulfate in bulk, mainly for my turf, BUT, if I need a hit of N to back off some yellowing leaves in weed then I might drop a pinch in a gallon of rain water for my cannabis faves, soil culture.

In a nutshell, nutrient uptake is a function of osmotic pressure across the root gradient initiated by transpiration which reduces plant tissue turgor pressure, creating a vacuum if you will at the roots. I may not have articulated this too well but you get what I mean.

Uncle Ben

I honestly don't know. I believe it's a lab average though. It doesn't fit a specific growing style, that I can see.
Late for work... so can't chase up the lab, but the name is there somewhere

 

[xtsho]

I never use any P/K boosters. I use inexpensive nutrients from start to finish in mild to moderate levels. There is absolutely no need to do anything more.

One thing I've found with many that overcomplicate their feeding is so many are constantly chasing one thing or another. Wasting time testing runoff, pH, etc... Just feed your plants a basic nutrient from start to finish and they should stay healthy from seed to harvest. A majority of issues people have is due to overfeeding too much of something which causes issues with other nutrients. Then many think they have a deficiency and dump more stuff on their plants exasperating the problem. In the end they end up running around in circles like a dog chasing it's tail.

Cannabis does not require a dozen bottles of additives and boosters delivered at this week or that week of growth. It's one of the easiest plants to grow from my experience. Just give it a good environment, plenty of light, any basic nutrient, and it will thrive. There's no need for complicated feeding charts or overpriced bottles. If you really think you need a booster save yourself some money and just get some monopotassium phosphate for around $10 a pound for water soluble hydroponics grade. You can also get potassium sulfate 5 pounds for around $20. With that you can make gallons and gallons of those $25 one liter bottles of bloom booster.