Marijuana plant hormones

Although many marijuana growers don’t know much about plant hormones, the fact is that they are hugely important to any marijuana plant (or any plant at all, for that matter). They signal to the body of your plant that it’s time for the plant to perform certain processes as well as produce certain parts the same way. They are chemicals that are essential to a plant’s well-being.

Hormones are found and created in many different areas of the plant, and then they move to where they need to go. Hormones increase and decrease, according to what the plant needs. Hormones can be added by the grower to help with different processes at various stages of the plant’s life. A thorough understanding of hormones is necessary, however, as they are quite strong in even smaller doses

Marijuana plant hormone products

Rooting hormones

One of the most common uses of commercial hormone products is to produce clones. These products are often referred to as “cloning gel” or similar products. There are three forms of rooting hormone products: liquid, powder, and gel.

Rooting Hormones Liquid


The liquid form of rooting hormone can be either the ready-made kind or the concentrated kind. The ready-made one is useful because of its convenience since its percentage is generally just right. That said, it’s usually not a good idea to dip the plant straight into the bottle of the product for hygienic reasons.

The concentrated version needs to be diluted before use. This is certainly less convenient, but it is also quite useful for people who know exactly what their plant needs. This is because it can be molded and customized to a specific ratio and concentration.

Product Example:

General Hydroponics Rapid Start for Root Branching – 125 mL ($17.27) 


The powdered form of rooting hormones is generally used by commercial growers, but also some hobby marijuana growers. They are quite useful if you won’t use the whole bottle within one grow season since the powder lasts longer than any other products out there. For that reason, it is preferred by many and can be bought in larger amounts without wasting any of it.

Generally, the method for applying powder is to dip the cutting into some water and then right into the powder and then tap it a bit, so some excess falls off. Then simply put the cutting into the grow medium that you have prepared.

Example Products:

Garden Safe TakeRoot Rooting Hormone – 12 pack ($57.09) 

RootBoost Rooting Hormone – 2 oz. ($6.79) 


The gel version of rooting hormone products is preferred by indoor growers. It is beloved for its high level of convenience as well as great coverage. By great coverage, we mean that it literally can cover the entire stem portion simply because of its consistency. This allows for particularly efficient absorption of the hormones.

To use, put the gel into some kind of container and then dip the cutting right into it. Do not dip it right into the bottle, even though it is temptingly convenient, as that could inadvertently spread disease.

Product Examples:

HydroDynamics Clonex Rooting Gel ($18.99 for 100 mL) 

Quick Clone Gel – 75 mL ($14.97) 

Other hormone products

Kinetin (Synthetic Cytokinine)

Cytokinine generally helps with germination, flowering, reduction of aging speed, and when in combination with other hormones (such as auxin or ethylene) they help with mitosis, leaf formation, the aging of leaves, chloroplast development, and so on. The synthetic form of Cytokonine is most commonly Kinetin. Try Bonide Tomato and Blossom Set Spray ($13.89 for 32 ounces), which helps increase crop yields, produce seedless fruit, and increase budding in general.

Also read “How often should I give my cannabis plants nutrients?


Ethylene plays a significant role in the growth of a plant. It ripens fruit faster, thickens the stems of plants, and slows the growth of plants. Too much Ethylene can kill off or harm the plant, so use with caution. When used correctly, it can help form flowers, drop leaves, sprout buds, and germinate seeds.

Ethylene is commonly found in a variety of products. You can find it in any of the following: Arvest, Etherverse, Cerone, Chipco Florel Pro, Prep, Etheral, Flordimex, Flordimex T-Extra, and Bromeflor.


Brassinolide is the steroids of plant hormones. It boosts growth significantly. Overuse is not recommended, but when used properly it helps with hormone regulation, helping with root growth, helping with photosynthesis, helping with phototropism, and more.

Brassinolide cannabis plants
Brassinolide cannabis plants

Brassinolide is a natural hormone in the Brassinosteroid family of hormones. It can be dissolved in water and put directly on leaves or seeds for germination. You can buy it from Power Grown (10 grams for $17.99).


Jasmonates help with reproductive development, growth, photosynthesis, and defense against external stressors. Use MeJa (Methyl jasmonate) to help with plant defense, germination, root growth, flowering, and more. Jasmonic acid can be purchased to create a spray, as can artemisia tridentate (which is sagebrush that naturally produces jasmonic acid).

How to use marijuana plant hormones

Plant hormones are not used the same way nutrients are, (as part of a daily or weekly regimen). Rather, they should be used intentionally and sparingly, only when specific situations arise or growing phases approach. Much research still needs to be done on the application of plant hormones on marijuana plants, but this information is at least a start to being able to use them safely and effectively.


Gibberellic Acid

When too much of Gibberellic Acid is used, it can be harmful to your plants. In fact, the natural overproduction of Gibberellic Acid is a sure sign of a plant in stress. If you plant is starving, this hormone (and others) will be overproduced and could lead to plant death. Low concentrations of Gibberellic Acid, however, can be highly beneficial.

Germination process marijuana seeds
Germination process marijuana seeds

If seeds are in any kind of dormancy (where they won’t germinate), applying a little bit of Gibberellic Acid can help overcome said dormancy. In fact, it could even lead to a faster germination than otherwise. Try using about 2 ppm of Gibberellic Acid on your seeds when trying to get to germination.

Vegetative phase

Gibberellic Acid

This can also work for young plants after they have germinated. By the time they are developed enough (past being considered “seedlings”), your plants can go through premature flowering from the application of Gibberellic Acid. The application does need to be repeated in order to sustain the flowering.

Hybrid Marijuana Seeds

Buy high yielding seeds

  • Bred to produce a large crop of marijuana
  • Maximize the crop and meet legal limit
  • Choose from several high-quality strains

Male flowers will begin to form if you use between 10 and 200 ppm, while female flowers will require between 200 and 300 ppm to prematurely appear. If more than 600 ppm is used, however, then it will have the opposite effect and will hinder flower development.

Gibberellic Acid may also stimulate growth when applied in certain areas.


Using an Auxin such as indole acetic acid (or “IAA”) helps with plant size increasing, root growth increasing, stimulating growth in general, and sometimes even increasing the growing season when applied late enough.

Auxin cannabis plant
Auxin cannabis plant

When combined with Brassinolide, this can help with cell expansion and cell elongation.

Fulvic Acid

Once the marijuana plant is established enough to be considered “adult” (likely around week two), fulvic acid can be applied to the plants. Although not a hormone in itself, it can do wonders for the transport of plant growth hormones when it is applied to the foliage of a plant. Because it permeates the cell walls, it assists with the absorption of plant hormones in general.


The most commonly used Cytokinine, Kinetin, can be applied to your plant during the vegetative phase to help with cell division, the development of new growth (such as buds, branches, and shoots), cell enlargement that leads to leaf expansion, and so on. Use a spray (such as the Bonide Tomato and Blossom Set Spray) to spray it on your plants and encourage better growth and bigger yields later.

Need more tips for growing healthy marijuana plants, sign up and receive our free grow bible.

Flowering phase


Increase the female flower production by diluting Ethylene in water and spraying it directly on your plants. Do this before the pre-flowers appear, but towards the end of the vegetative phase. Any synthetic form of ethylene will convert to actual ethylene quite rapidly after making contact with the plant itself (such as when you use ready-to-use Ethephon or concentrated Ethephon that you diluted first).

Gibberellic Acid

This could also be applied to marijuana plants during the flowering phase to help with potential frost damage when the buds are flowering. Spray the plants with it to get this effect.

Flowering Phase
Flowering Phase

Ultimately, plenty of research still needs to be done on the use and application of plant hormones on marijuana plants. Differences in the environment, stressors, grow setup, and even the strain of the marijuana plants themselves lead to considerable alterations in the effects that these hormones may have.

For that reason, trial and error may be the best way to figure out for yourself which hormones work best for your particular grow situation. Just remember: plant hormones are powerful things, so keep everything in moderation because too much of one type of hormone can do more harm than good.

Avatar for Robert Bergman

Robert Bergman


Robert Bergman is an Amsterdam-based marijuana grow expert who has years of experience from small grows to massive operations ... See profile

43 comments on “Marijuana plant hormones”

  1. Hate to mess around with something doing just fine. Always open to new ideas but if there is any chance of killing my beloved babies I chose to let them grow without messing with them.

  2. Thank you soo much. I see the tomato plant product in all the big box retailers. Now I know it is useful and helpful. Keep the great articles coming. It makes me wish I were smarter.

  3. plant hormones can be found on ebay, some of them are water soluble, some are not. alcohol and/or polysorbate 20 are used to dissolve them. in some applications even minute quanities of 2 ppm can be too much, but there is not an lot of info on the use of these hormones with mj, though there is some info on horemones and other crops. do your research, some of these can be dangerous.

    • robert,

      Pretty good info. ON the other hand; I would like to clarify. Make sure you know from a trusted and knowledgeable source what you want before going to ebay. Some products are crap, and it is best if you shop from an informed perspective. Thanks for sharing. 🙂

    I adore these articles. I used to be overwhelmed by all of this nitty gritty weed talk, but the more i read and researched, in written form and with some hands on experience, it made me want to learn more and more. Now i’m reading these emails every single time they hit my inbox – which doesn’t even happen with my aunt’s emails. You are a wealth of very awesome information. Thanks for all of your help and keep up the great work!!

    • laura,

      ON behalf of all of us at ILGM; Thank you foe the kind sentiment, and we hope to continue to bring a smile to your face with our new articles.

      Have a great growing day, lw

  5. I’m surprised there’s no mention of chitosan oligosaccharide. I’ve heard good things about it’s pest/fungus prevention and increased trichome production. ILGM, do you folks have any opinion of that compound?

    • Nijo,

      We get so many products bombarding the market these days. So; I will look into the product you mention. Meanwhile; I suggest you join our support forum. We have many knowledgeable and friendly members and experts alike, and I am sure someone has read up on your product. Join us: 🙂

  6. I do not see what good it is to know these things if we do not know where to get these hormones. Are they naturally occurring or do they have to be bought? Is there a place to acquire these items?

  7. gary,

    We recommend you do what comes natural to you. Stay within your comfort zone. Advanced plant manipulation is not for everyone. Robert is just sharing knowledge. Some will find it useful while others question the value of using such a technique.

    Happy growing

  8. OK but how does this help me? Looks like messing with plant hormones is for botanists, seems too dangerous for amateur growers. Is there something useful for us in here?

  9. Vey informative! Many thanks!! Q: Where can one obtain these hormones in a natural form? I don’t like synthetics. Thank you again. medMUser

  10. Not really relevant to this topic perhaps, but a couple of Q’s for you…I am a medical patient here in Canada, looking into growing my own as cannot afford to keep purchasing at 8 – 15 bucks a gram…are you familiar with using cinnamon to retard (prevent) mould from forming around a plant, and would it be OK for marijuana growing do you think? It works beautifully in the garden when growing pumpkins, and I use it on my hibiscus plants (indoors) to keep mould from forming on the top of the soil. Second Q, just read about coconut water (on and it was suggested that coco water is a great boost for plants. Thoughts? Cheers from still-snowy Chelsea, QC…Mel

    • Mel,

      All I can say about your idea is that id it worked in the veggie garden; It might be an option. I would really like to look into this and I ask that you come and join our support forum in order to share your idea with the community. I hope to see you there

  11. Nice article. I find the practical application of hormones requires a lot of scientific effort. I’ve debilitated plants experimenting. It’s been worth it, and continues to be.

  12. My word what an article.Explained many mysteries to a struggling reader who is not well educated in biochemistry.Enlightening.Would be great to know when to use and how to use these trigger hormones at various times and how to treat plant to trigger responses that lead to bigger,tastier crops..I will do more background on plant physiology after this article.Enlightening article.

  13. Wow, what an incredibly detailed post, Robert. However, I’d love to see you tell us exactly how to obtain the best results using these hormones. What do you do with your own plants? I bet your other readers would also like to learn the best system for using hormones.
    Thanks, Mike

  14. This is extremely helpful for any plants. In easy to understand language considering the subject and what is necessary to explain this scientific process properly.

  15. Very interesting information, a lot to sort out. How do I incorporate this info into my growing regime? Do yo have a program that I could reference? Where can I get the product?

  16. It had quite a few unpronounceable words, would you be able to recommend an “all in One” fertileizer in my hydroponic water.

    • Rick Parker,

      Well, my friend. Although this article has nothing to do with an all in one hydroponic nutrient; I must say; “You are in luck today!”

      I recommend you try “Flower Power” Robert’s 4 stage water soluble powder nutrient. I invite you to join our community 🙂 I had the opportunity to do a grow with this new product. It is the easiest to use. Flower Power dissolves quickly and cleanly. You will be amazed. The starter pack:

      You might even get a $5 discount. See you at ILGM

  17. Interesting article but it would be helpful if you could give a short list of easily available organic products which can help supply these hormone for those of us who don’t have a degree in chemistry.

    • I’m with Patrick Monk. Love to give them a try in my soil garden. Great article!!


    • sea kelp (aka kombu) has most of the above mentioned hormones; they an easily be made bioavailable if you make a miso soup broth and then rinse the left over kombu, shred it and mix it back in with RO water before applying to seedlings at transplant time. that’s an inexpensive and organic way of getting a head start for your seedlings (i generally do this when transplanting hardened seedlings outdoors along with a good dose of mycorrhizae