Stimulants / Plant Grow Regulators (PGR)

Tatace · Jun 6, 2025

Hi everyone,
I’d like to share my experience because I think many people here might relate:
I’ve been growing for 3 years now, and ever since I started, I’ve been constantly optimizing every single aspect: aeroponics, lighting, temperature, humidity, nutrients, training techniques, pest control.
I’ve reached a solid overall result, managing to produce 480g of buds with just 200 watts of LED lighting. Still not satisfied, I went further and optimized the nutrient solution by creating a formula entirely based on scientific research, aimed at maximizing yield as well as cannabinoid and terpene production.
I also incorporated foliar triacontanol, silicates, and Trichoderma harzianum into the grow to give it an extra boost.
Yeah, I’ll admit I got a bit obsessed with all of this, haha.
After all that work, I knew I’d eventually hit a plateau. At this point, there are only two variables left that I can still tweak: genetics (I grow autoflowers only out of necessity, so switching to clones isn’t an option), and possibly stimulants.
And that’s exactly where I’d love some help: I’ve found very little detailed info online about individual compounds (not pre-mixed commercial formulas), and I’m hoping some of you might be able to share your experience with different substances — their benefits, risks, application methods, and concentrations.
I hope others will chime in and share their experiences too.
Peace <3

Here’s my contribution regarding Triacontanol:
I’ve personally seen great results using a weekly foliar spray of triacontanol (at 50–100 PPB concentration). After application, there’s a noticeable growth boost. It’s a completely natural compound, safe for consumption, and it also seems to stimulate the plant’s immune response.
Triacontanol is very affordable, but its pure form is water-insoluble. To make it usable, you just need to add an emulsifier like polysorbate 80 to your solution.

HerbalEdu · Jun 6, 2025

PGRs are naturally occurring and synthetically produced compounds that affect plant growth. They can increase cannabis yield but reduce terpene and cannabinoid production.

RoadKillSkunkHunt · Jun 6, 2025

Tatace said:
Hi everyone,
I’d like to share my experience because I think many people here might relate:
I’ve been growing for 3 years now, and ever since I started, I’ve been constantly optimizing every single aspect: aeroponics, lighting, temperature, humidity, nutrients, training techniques, pest control.
I’ve reached a solid overall result, managing to produce 480g of buds with just 200 watts of LED lighting. Still not satisfied, I went further and optimized the nutrient solution by creating a formula entirely based on scientific research, aimed at maximizing yield as well as cannabinoid and terpene production.
I also incorporated foliar triacontanol, silicates, and Trichoderma harzianum into the grow to give it an extra boost.
Yeah, I’ll admit I got a bit obsessed with all of this, haha.
After all that work, I knew I’d eventually hit a plateau. At this point, there are only two variables left that I can still tweak: genetics (I grow autoflowers only out of necessity, so switching to clones isn’t an option), and possibly stimulants.
And that’s exactly where I’d love some help: I’ve found very little detailed info online about individual compounds (not pre-mixed commercial formulas), and I’m hoping some of you might be able to share your experience with different substances — their benefits, risks, application methods, and concentrations.
I hope others will chime in and share their experiences too.
Peace <3

Here’s my contribution regarding Triacontanol:
I’ve personally seen great results using a weekly foliar spray of triacontanol (at 50–100 PPB concentration). After application, there’s a noticeable growth boost. It’s a completely natural compound, safe for consumption, and it also seems to stimulate the plant’s immune response.
Triacontanol is very affordable, but its pure form is water-insoluble. To make it usable, you just need to add an emulsifier like polysorbate 80 to your solution.

I'll pass ...

Here's why ... Even though there's documentation that support your findings, there's zero documentation recommending smoking cannabis that has been treated with polysorbate 80. In fact, the use of polysorbate 80 in reference to cannabis is in emulsifying cannabis oil so it mixes better when used with edibles. I didn't find any studies recommending the use of this on cannabis that will be smoked.

Tatace · Jun 6, 2025

HerbalEdu said:
PGRs are naturally occurring and synthetically produced compounds that affect plant growth. They can increase cannabis yield but reduce terpene and cannabinoid production.

I believe it really depends on the PGR (Plant Growth Regulator) you choose. Some are more focused on productivity, while others on quality. If I’m not mistaken, jasmonic acid has been shown to significantly increase cannabinoid and terpene concentrations. Of course, you can’t have it all at once, but this is exactly why I think a thread that compiles all this information could be really helpful for many people. It would allow them to make informed decisions instead of opting for pre-made products with questionable ingredients.

RoadKillSkunkHunt said:
I'll pass ...

Here's why ... Even though there's documentation that support your findings, there's zero documentation recommending smoking cannabis that has been treated with polysorbate 80. In fact, the use of polysorbate 80 in reference to cannabis is in emulsifying cannabis oil so it mixes better when used with edibles. I didn't find any studies recommending the use of this on cannabis that will be smoked.

I understand your concern, if you want to do some research about a natural emulsifier that makes you safer during consumption, I will be happy to read and possibly integrate the information with what you have found :)

RoadKillSkunkHunt · Jun 6, 2025

Tatace said:
I believe it really depends on the PGR (Plant Growth Regulator) you choose. Some are more focused on productivity, while others on quality. If I’m not mistaken, jasmonic acid has been shown to significantly increase cannabinoid and terpene concentrations. Of course, you can’t have it all at once, but this is exactly why I think a thread that compiles all this information could be really helpful for many people. It would allow them to make informed decisions instead of opting for pre-made products with questionable ingredients.

I understand your concern, if you want to do some research about a natural emulsifier that makes you safer during consumption, I will be happy to read and possibly integrate the information with what you have found :)

It's not my study.

@Tatace - Personally, beyond using a bit of clone-ex for clones, I don't use PGRs on anything I grow. Since this is your study and your area of expertise, I challenge you to provide that information side by side with the rest of your findings so people can get as complete and informed view as possible. Consumer safety, after-all, should not be over-looked and should be something important to you as you further your studies.

Tatace · Jun 6, 2025

RoadKillSkunkHunt said:
It's not my study.

@Tatace - Personally, beyond using a bit of clone-ex for clones, I don't use PGRs on anything I grow. Since this is your study and your area of expertise, I challenge you to provide that information side by side with the rest of your findings so people can get as complete and informed view as possible. Consumer safety, after-all, should not be over-looked and should be something important to you as you further your studies.

As far as I'm concerned I have no problem with polysorbate-80 being an additive commonly used in the food industry, of course we could discuss the effects it has when smoked but we should take into account that anything, if smoked, is intrinsically carcinogenic; even our beloved cannabis. I think it's important to indicate which PGRs are carcinogenic or genotoxic but I believe that if a molecule is safe there is no reason why if applied to a plant it would transform into something dangerous. I want to specify that I smoke a part of the cannabis I produce and I have no intention of increasing the quantities at the expense of my health and even if I didn't smoke it I would feel bad about "selling" the health of my consumers, however I understand that it is not a topic in which many people want to invest energy so I respect your decision :)

RoadKillSkunkHunt · Jun 6, 2025

Tatace said:
As far as I'm concerned I have no problem with polysorbate-80 being an additive commonly used in the food industry, of course we could discuss the effects it has when smoked but we should take into account that anything, if smoked, is intrinsically carcinogenic; even our beloved cannabis. I think it's important to indicate which PGRs are carcinogenic or genotoxic but I believe that if a molecule is safe there is no reason why if applied to a plant it would transform into something dangerous. I want to specify that I smoke a part of the cannabis I produce and I have no intention of increasing the quantities at the expense of my health and even if I didn't smoke it I would feel bad about "selling" the health of my consumers, however I understand that it is not a topic in which many people want to invest energy so I respect your decision :)

I think the bottom line here is its known to be safe for consumption ... meaning eaten. Ethically, to me if you were marketing your finished product to a buyer, that buyer would be using it to make something edible. Granted, the fact that combusting anything does create carcinogenic chemicals, I'll give you that ... but it doesn't make it an excuse to say its ok to smoke it.

That's not an accusation though ... nothing you said could be contrived to mean that. Just keep things as transparent as you can about the use of PGRs.

figolus · Jun 6, 2025

I use Liquid Ocean as a spray during growth, and during flowering, I add it to my irrigation water. You can grow an entire crop with it by adding Bloom for flow without adding PK13/14. It's Seaweed. I have very good results.

https://www.hydropassion.eu/fr/nos-produits/liquid-ocean

Otherwise, I'm thinking of adding Aptus Regulator as a spray, alternating every other week with Liquid Ocean.

Smoking Gun · Jun 6, 2025

@Tatace you should very much look into the use of kelp and how it can adjust the growth of a plant. It also appears to aid in the development of flavor in Cannabis as well.

Along those lines are aloe, soap bark (quillaja), coconut and lots of other plant products. Being made from plants themselves, these products often contain naturally occurring PGRs.

Then there is humid and fulvic acids to look into. They are useful in the absorption and, if I am not mistaken, the usage of nutrients.

I would recommend doing a YouTube search for Harley Smith or NPK Industries, this topic is his exact wheelhouse. From his telling he went down the same rabbit hole you are going down now.

Thatoneguyyouknow_ · Jun 6, 2025

have played with a few foliar applied growth regulators personally, commercially and privately both, the only beneficial outcome you are going to see is to your gram/watt ratio and consistency between different unrelated cuts. And only one of those is even desirable as a cannabis *consumer.

If you have to maintain a bottom line, and profit margins, its not a stupid move to make. If you are growing cannabis for your own personal consumption and passion for the plant, its a very unwise decision to make.

I moved away from PGR's as soon as i no longer had to maintain a certain degree of profitability with my home growing. And all of a sudden i could tell the differences to the minute detail between all my plants and their expressions when dialed. Everything unique about each plants starts to express far more fully if dialed in without hormone regulators.

Oh yea, i lost about 90-140 gram per m3 of flower yield..... But my resin yields per cubic foot of flower return adjusted for flower weight differences averaged out... didnt change at all. use your imagination there, its not hard to see what happened. Im at about 0.8lb per 32x32 tent at about 175w average. I could easily go beyond a pound every cycle with foliar PGR's. Reliably. By why would i do that if it lowers the quality of my hash and presses, while doing nothing for my bho pulls besides waste extra butane and make my purges take longer? But i dont sell flower on the fraction of a LB, so it only serves to *hurt* my current bottom line, which is not to turn a profit, its to produce high quality, unique flower, on as little investment as possible. Which is most home grower's bottom line.

figolus · Jun 6, 2025

Thatoneguyyouknow_ said:
have played with a few foliar applied growth regulators personally, commercially and privately both, the only beneficial outcome you are going to see is to your gram/watt ratio and consistency between different unrelated cuts. And only one of those is even desirable as a cannabis *consumer.

If you have to maintain a bottom line, and profit margins, its not a stupid move to make. If you are growing cannabis for your own personal consumption and passion for the plant, its a very unwise decision to make.

I moved away from PGR's as soon as i no longer had to maintain a certain degree of profitability with my home growing. And all of a sudden i could tell the differences to the minute detail between all my plants and their expressions when dialed. Everything unique about each plants starts to express far more fully if dialed in without hormone regulators.

Oh yea, i lost about 90-140 gram per m3 of flower yield..... But my resin yields per cubic foot of flower didnt change at all. use your imagination there, its not hard to see what happened. Im at about 0.8lb per 32x32 tent at about 175w average. I could easily go beyond a pound every cycle with foliar PGR's. Reliably. But i dont sell flower on the fraction of a LB, so it only serves to *hurt* my current bottom line, which is not to turn a profit.

In general, PGRs are used only during growth, for better plant development. In flowering, PGRs are stopped, and even before during stretching. Afterwards, in flowering, it is more the grower's eye that determines the rest, right?

Thatoneguyyouknow_ · Jun 6, 2025

figolus said:
In general, PGRs are used only during growth, for better plant development. In flowering, PGRs are stopped, and even before during stretching. Afterwards, in flowering, it is more the grower's eye that determines the rest, right?

many Wearhouse facilities apply light foliar PGR's several times throughout flower. I foliar apply feeds and corrective things to fan leaves in flower every now and then as well.

It doesnt affect flower quality if only kept in veg, but i nor anyone else i know thats up to snuff on their game has any trouble keeping vegetative material around and propagating more than you need, i throw as much away as i flower lol. You sell more clones than you run from most commercial Wearhouse facilities

Fun fact. Rooting hormone is a PGR technically. There are lots of them that are used for different purposes.

figolus · Jun 6, 2025

Thatoneguyyouknow_ said:
many Wearhouse facilities apply light foliar PGR's several times throughout flower.

It doesnt affect flower quality if only kept in veg, but i nor anyone else i know thats up to snuff on their game has any trouble keeping vegetative material around, i throw as much away as i flower lol. You sell more clones than you run from most commercial Wearhouse facilities

Fun fact. Rooting hormone is a PGR technically. There are lots of them that are used for different purposes.

Ok thanks I use it in the sprayer during growth and flowering in my watering .

Thatoneguyyouknow_ · Jun 6, 2025

figolus said:
Ok thanks I use it in the sprayer during growth and flowering in my watering .

Anything that stimulates a growth response in the plant without delivering it nutrition is considered a PGR iirc.

Don't quote me on that, haven't looked it up, it was just explained to me that way at a past job lol

Colloidal silver/silver thiosulfate for fem seeds is a PGR technically too. It plugs into ethelene receptors in the flowers and prevents ethelene from plugging into it, or something along those lines, and keeps it from telling the plant it's a female by doing so.

Stimulants / Plant Grow Regulators (PGR)

Stimulants / Plant Grow Regulators (PGR)

Tatace

HerbalEdu

RoadKillSkunkHunt

Tatace

RoadKillSkunkHunt

Tatace

RoadKillSkunkHunt

figolus

Smoking Gun

Thatoneguyyouknow_

figolus

Thatoneguyyouknow_

figolus

Thatoneguyyouknow_

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