"Does high phosphorus fertilizer increase flowering?" Dr. Bruce Bugbee answer.

**It Could use another day** · 08-05-2021, 06:00 PM

All I'm saying is adding bone meal to the same fertilizing schedule ive used increased my production.

I recommend everyone just do what works for them🤷🏾‍♂️

**PacNorWreck** · 08-05-2021, 06:36 PM

The nice thing about science is that you don’t have to rely on anecdotal evidence. The reason anecdotes are so prevalent is the variety of growing conditions we all have. Pots vs in-ground, sandy soil vs clay, compost vs gritty mix, rainy climate vs dry, hot vs cold, long season vs short, sun vs shade, organic ferts vs soluble, slow release vs fast - the list really goes on and on and on.

But at the end of the day, the best thing any grower can do is apply the science to their conditions, and the science is abundantly clear that 1) there isn’t much phosphorous in fig plant tissue, 2) most any soil or any fertilizer will have enough P that the plant will recognize that it has more than it needs to do what it wants, and 3) high P fertilizers are not necessary.

Also, P is a major pollutant. There’s a limited supply of it, it tends not to come back after we flush it into the ocean, and it is a major cause of algal blooms.

https://amp.theatlantic.com/amp/article/617937/

**cjccmc** · 08-05-2021, 06:37 PM

Thanks for sharing inputs from a credible expert on the subject.

I just recently watched a video made by one of the better Youtube channel gardeners on the topic of bloom booster fertilizers. He believes they work and I'm generally OK with people saying they believe something without a solid reason as long as what they do with it is relatively harmless to me and others. But I do find it annoying when they point to "proof" that is close to nonsensical and then try to promote their unfounded belief to others.

**oat** · 08-05-2021, 07:20 PM

Thanks for sharing this. I already know this but it’s good to get the knowledge around.
I usually don’t care if people do things that works for them, but phosphorus runoff is terrible for the environment. Phosphorus is also highly non-renewable. I think most of the world’s supply of rock phosphate is only in Morocco and that’s it.

**FigsNorth** · 08-05-2021, 07:43 PM

Originally posted by Salvatore View Post

After watching your YouTube video on Maximizing Cannabis, I recently switched to your 20-10-20 solution method with 10% runoff and test with a EC meter.

1. Is the video link you posted in you OP the video where you got those recommendations?

2. What ferts are you using to achieve 20-10-20? I have been using MG 20-20-20 and haven't seen (or perhaps haven't noticed) 20-10-20.

3. Also, what EC are you targeting for run-off? I use SIPs and used to measure my reservoirs with an EC meter, but have stopped doing it because I've been too busy.

I previously found a good resource for this type of info from here:

https://www.cocoforcannabis.com/toc/#fertilizers-water

**peppercuts** · 08-05-2021, 11:36 PM

Very interesting, subbed

**peppercuts** · 08-07-2021, 07:02 PM

Thanks for sharing the formula Salvatore , it's surprising simple. I like the addition of gypsum for calcium as the fertilizer he recommends lacks calcium which is a very important element and even dynagrow foliage pro can benefit from some added calcium.

**Drfig** · 08-08-2021, 12:49 AM

Well. Evidence is evidence. Anecdotes are just Anecdotes. Thanks for sharing

**Realtorbyday** · 08-08-2021, 02:37 AM

Wait a minute.... am I reading that wrong or is Dr B kinda saying 2 different things and counterdicting himself?

In the first part of his response, he clearly is against the idea. He uses the phrase "general scientific consensus" which is not the same as saying something like "the results from scientific experiments".

Then he says "For most crops 15-20 ppm P is adequate. In cannabis, our studies show a potential benefit of increasing to as much as 50 ppm P during the late flowering stage." Isn't he laying out clear evience that supports more P??

When you analyze his response, it almost sounds like he's against using extra P for environmental reasons rather than results (yield) based reasons.

I'm not sure that this clears up anything yet. People are still going to debate because this isn't really a very clear cut answer when you examine it.

Salvatore You wrote a really nice letter and did a wonderful job for the whole fig community. We need these kinda of answers. Thanks for pursuing this and trying to get answers for all of us.

**Realtorbyday** · 08-08-2021, 09:15 AM

We're lucky to have this forum and all its members so we can share and compare notes and results in real life gardens under all different conditions.

**AscPete** · 08-08-2021, 09:21 AM

Thanks for sharing this info, this discussion has been ongoing for decades, though plant nutrient requirements have remained constant.

https://www.houzz.com/discussions/13...ch-p-is-enough
Al Tapla 2008,
“We know that tissue analysis of leaves, roots, flowers - any of the live tissues of healthy plants will reveal that P is present in tissues at an average of 1/6 that of nitrogen (N) and about 1/4 that of potassium (K). Many plants even contain as much calcium as P. If we know that we cannot expect P to be found in higher concentrations in the roots and blooms than we find in foliage, how can we justify the belief that massive doses of P are important to their formation?

It is well known among experienced growers that withholding N when all other nutrients are available at adequate levels induces bloom production, even on smaller and younger plants. Though plants USE nutrients at approximately a 3 : 0.5 : 2 ratio (note that N is 6 times the level of P, and K is 4 times the level of P), most greenhouse operations purposely fertilize with something very near a 2:1:2 ratio to limit vegetative growth so they can sell a compact plant sporting pretty blooms to tempt you.

Simply limiting N limits vegetative growth, but it does nothing to limit photosynthesis. The plant keeps making food, but it cannot use it to grow leaves and extend stems because of the lack of N. To where should we imagine the energy goes? It goes into producing blooms and fruit."

**Jafi** · 08-08-2021, 09:24 AM

I use the KNF Korean natural farming method. Comfrey tea as a fertilizer and grow microbes in 5 gal buckets with compost and worm castings plus lactobasilis, mycorizie and other natural fermented fruit juices. Twice a month in growing season. In ground and potted plants. They need nothing else.

**AscPete** · 08-08-2021, 09:47 AM

Originally posted by Realtorbyday View Post

Ok, so do I understand that what you are saying is that it's important but in much lower levels and in a somewhat different ratio than we've all been advertised into believing is ideal? And only if it's actually missing from the soil and it's probably not. Do I have that about right? I'm not being a smart ass, I'm trying to understand your thinking because I think you've got it right.

Yes, Plant and Ficus carica Tissue Analysis clearly shows the relative Plant Nutrient requirements.

Soil Nutrient Analysis would indicate whether it needs to be added for in-ground plants.
For Potted Culture in 'Sterile' Potting Medium it would always be required.

Fertigating until runoff with Water Soluble Fertilizers in potting medium is essentially Hydroponic Culture where the 'Soil Solution' (Nutrient Solution) is maintained at 'Optimal Concentrations'....

**PacNorWreck** · 08-08-2021, 04:55 PM

AscPete is there a 2-1-2 fertilizer you recommend? Or just use 3-1-2 and add some K occasionally?

**LADPT** · 08-08-2021, 08:30 PM

What’s a guy who bought a 25# bag of Jacks Blossom Booster supposed to do with it?…asking for a friend

**abdophoto** · 08-08-2021, 09:07 PM

TheMillennialGardener Time to do a experiment next season. Two exact same cuttings from same mother tree. One fed consistent 20-20-20, the other with your variable feedings or perhaps just bloom booster and see the results.

Or maybe 3 cuttings:

1. 20-20-20
2. 10-30-20
3. Variable solutions

And watch the results.

**TheMillennialGardener** · 08-09-2021, 08:04 AM

Originally posted by Salvatore View Post

The problem is that P is a serious environmental pollutant; so applying excess P is irresponsible. Agricultural researchers have been trying to get grower to apply less P for many decades. Responsible growers should start marketing their products as being grown without excess phosphorous.

For most crops 15-20 ppm P is adequate.

And that, right there, is your answer.

Does high phosphorous work? Yes. The problem is that it is "a serious environmental pollutant," so interests are doing whatever they can to dissuade its use. That includes designing studies to have a certain outcome. Yes, if there is phosphorous built up in soil that is in excess of what the plant needs, adding more isn't going to help. What % of backyard gardeners is that going to represent? How many of us are gardening on abused farmland?

Almost none of us are growing in environments with excess phosphorous, so it is absolutely incorrect to make the assumption that it doesn't work because we're growing in those conditions. The actual answer is, "Yes, they work as long as you're not growing in an environment with excess phosphorous," but we can't have that answer, because that will promote the use of the product.

It's getting harder and harder to find real science these days. Most studies are rigged to deliver a certain outcome, and that outcome is then used to drive public opinion and lead to legislation banning or funding promoting the use of certain things. It's truly awful what is going on, and it makes it impossible to trust any information out there. Grow 9 tomato plants in containers in identical mediums. Give three 24-8-16, give three 15-30-15 and give three 18-18-21. They will grow differently. I guess I'm going to have to do this next March.

I absolutely cringe when I hear general scientific consensus. Thanks to "general scientific consensus," we would still be living in a world where the sun revolves around the Earth, it is a badge of honor to have the bloodiest, dirtiest operating rooms and dirtiest surgical instruments because it showed how popular you were, hand-washing would be ineffective at stopping disease, and there would be no reason to clean up the water supply to prevent cholera since that's not where it came from. They were all general scientific consensuses of their time.

**fisherman** · 08-09-2021, 09:07 AM

I actually did an informal version of the tomato test a number of years ago when I lived in the northeast. Two identical tomato plants, one fertilized with regular Miracle Gro (24-8-16) and the other with Miracle Gro for tomatoes (18-18-21). Noticeably higher fruit yield on the plant fertilized with Miracle Gro for tomatoes. Used the latter thereafter. Tomatoes were planted in ground in soil heavily amended with refined compost available from the town that I lived in.
Also, my reaction to the professor’s response was that it was tainted by his need to be politically correct by discouraging the use of additional phosphorus.

**AscPete** · 08-09-2021, 10:06 AM

Originally posted by TheMillennialGardener View Post

And that, right there, is your answer.

Does high phosphorous work? Yes. The problem is that it is "a serious environmental pollutant," so interests are doing whatever they can to dissuade its use. That includes designing studies to have a certain outcome. Yes, if there is phosphorous built up in soil that is in excess of what the plant needs, adding more isn't going to help. What % of backyard gardeners is that going to represent? How many of us are gardening on abused farmland?

Almost none of us are growing in environments with excess phosphorous, so it is absolutely incorrect to make the assumption that it doesn't work because we're growing in those conditions. The actual answer is, "Yes, they work as long as you're not growing in an environment with excess phosphorous," but we can't have that answer, because that will promote the use of the product.

It's getting harder and harder to find real science these days. Most studies are rigged to deliver a certain outcome, and that outcome is then used to drive public opinion and lead to legislation banning or funding promoting the use of certain things. It's truly awful what is going on, and it makes it impossible to trust any information out there. Grow 9 tomato plants in containers in identical mediums. Give three 24-8-16, give three 15-30-15 and give three 18-18-21. They will grow differently. I guess I'm going to have to do this next March.

I absolutely cringe when I hear general scientific consensus. Thanks to "general scientific consensus," we would still be living in a world where the sun revolves around the Earth, it is a badge of honor to have the bloodiest, dirtiest operating rooms and dirtiest surgical instruments because it showed how popular you were, hand-washing would be ineffective at stopping disease, and there would be no reason to clean up the water supply to prevent cholera since that's not where it came from. They were all general scientific consensuses of their time.

I have to point out the portion of Dr. Bugbee's answer that is missing from your quote...

OP question;
Does high phosphorus fertilizer increase flowering?

Dr. Bugbee's answer;
The general scientific consensus is that high P does not improve flowering. I am not aware of any evidence that it helps flowering, especially in tomatoes. I have never studied Figs, but I do not expect they would be different.

Dr. Bugbee proceeds to explain that excessive amounts of Phosphorus are not required or needed, because even in his Cannabis Research an average concentration of 50 PPM Phosphorus is considered higher than normally required. This 50 PPM is noteworthy because the 20-10-20 Fertilizer has ~ 68 PPM Phosphorus at the typical 1 tsp/gallon application rate

Its a circular argument to claim that because excessive amounts of Phosphorus "Works" its the only or even better approach when the Scientific evidence shows that there isn't even 100% Phosphorus in plant tissue relative to the other Macro-nutrients
The Scientific and Technological Advancements over the past 200 plus years have lead us to the current understanding of our Environment, Astronomy, Biology, Chemistry, Horticulture, etc., all due to Science and Scientific Consensus...

**TheMillennialGardener** · 08-09-2021, 10:59 AM

Originally posted by AscPete View Post

Its a circular argument to claim that because excessive amounts of Phosphorus "Works" its the only or even better approach when the Scientific evidence shows that there isn't even 100% Phosphorus in plant tissue relative to the other Macro-nutrients
The Scientific and Technological Advancements over the past 200 plus years have lead us to the current understanding of our Environment, Astronomy, Biology, Chemistry, Horticulture, etc., all due to Science and Scientific Consensus...

You're creating a straw man, then arguing the straw man. That is a logical fallacy. Nobody is advocating for "excessive" amounts of anything. "Excessive" by definition means that it is too much. Anything in "excess" is bad - that's what "excess" means.

The problem is, the guy's response is just plain wrong. There are no scientific consensus, and phosphorous is absolutely necessary for flowering. You can't make your argument using the "excessive case" and claim that because when phosphorous is in overabundance, adding more won't help, so therefore phosphorous doesn't add to flowering. That is crazy. As I said in the comment above, what he's actually saying is:

"Because phosphorous usage has contributed to a lot of environmental damage, we're trying to dissuade people from using it in their practices. We still don't know what the bare minimum amount of phosphorous required is, but most of us are blanketly telling people not to use a lot of it because we'd rather dissuade the usage overall at the expense of people's production."

That response is agenda driven, not scientific, and it's getting harder and harder to find honest people out there willing to find the true results.

Run the experiment yourself and you'll prove yourself wrong. I've done this many times, and I guess I'm going to have to film the next one next season. Phosphorous boosts flowering, and trying to single out an isolated case where there may be an overabundance of bioavailable P in the soil to try and blanketly discredit it is fraudulent.

**TheMick27** · 08-09-2021, 11:44 AM

Some may find this study of interest:

Effect of N-P-K Fertilization on the Yield and Nutrient Status of Fig (Ficus Carica L. Cv. Kalamon) Trees Grown under Mediterranean Conditions

The results showed that N is an important nutrient for the yield of the fig tree. The highest fruit production was recorded in the trees treated with Ν₁Ρ_1.2Κ_0.6. Interesting yields were recorded in the Ν₁Ρ_1.8Κ_0.6 and Ν_0.3Ρ_1.2Κ_0.6 treatments and the treatment Ν_0.3Ρ_1.2Κ_0.6 was suggested that it requires further research as the most economical one. These treatments gave the highest yields with relatively early harvest maturity. Yield in relation to the doses of NPK nutrients can be described by a multiple secondary regression equation.

https//www.tandfonline.com/doi/full/10.1080/15538362.2020.1836706

**elriba** · 08-09-2021, 11:52 AM

This is a very interesting post. I have a couple of questions about using soluble fertilizers that this post got me curious about:

1) Salvatore said "I'm using 20-10-20 every feed with a 10% runoff at 1.3 millisiemens / centimeter EC or 910 tds." Why is it important to measure the runoff and its' total disolved solids?

2) Why is it that when using liquid fertilizers what is important is the concentration of nutrients and not the total amount of nutrients given to the plant? For example, a recommendation of a 50ppm phosporus concentration during the flowering stage, for cannabis, was given. I don't understand why recommendations are given like this. If I fertilize the plants every day with this solution of 50 ppm, versus if I fertilize only twice a week with the same solution, it would seem to me that there would be a huge difference in the fertilization the plants get. There must be something I don't understand.... How does this work?

Finally, can you guys recommend a good textbook, or source of information for a beginner who wants to understand better these things?

**PacNorWreck** · 08-09-2021, 12:26 PM

I am getting so tired of this argument going back and forth.

At the end of the day, there is agreement amongst the agriculture industry (as proven by data, results, and experiments shared many times over by AscPete and who have livelihoods and literal billions of dollars vested in proper fertilization); professors of horticulture (as shown in the OP and a number of other places such as this one: https://s3.wp.wsu.edu/uploads/sites/.../phosphate.pdf ); and nutrient analysis of the P content of fig plant tissue (thanks again to AscPete ).

On the other hand you have one Youtuber who just so happens to sell bloom buster fertilizers through his affiliate-link amazon store, who uses ad hominem attacks against scientists and seems to think there is some environmentalist conspiracy to keep your tomatoes from blooming, whose idea of an experiment is getting literally one of the most flower-happy citrus in existence to put out 10 blooms on a 6-foot tall tree with a control group of… a completely unfertilized avocado tree next to it. Coastal NC has had ~2700 GDD50 heat units already. Of course figs do well there.

I’m sorry. I’m just so tired of having to relitigate this every month. It’s exhausting - someone makes a post asking about fertilizer, studies and science and evidence are shared, then someone tags their favorite YouTuber and we have to do this again.

**oat** · 08-09-2021, 12:43 PM

PacNorWreck AscPete Eric, Pete you guys are great! Thanks for keeping the forum sane.
I have a Meyer lemon that I never fertilized with any bloom booster fertilizer. My 2 ish-year-old tree is smaller than that tree but I have 10 times the bloom on just one branch. Does my experience say that Phosphorus is not necessary? Maybe or maybe not but the point is it's not statistically significant. What I find the most cringe-worthy is when people twist science around. There are numbers, people. People have biases, that is why scientists came up with a way to measure things as unbiased as possible. Numbers are trustworthy and numbers said that bloom booster fertilizer is not necessary for high production.

"Does high phosphorus fertilizer increase flowering?" Dr. Bruce Bugbee answer.

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