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How to use plant hormones in vegetative and flowering phase to boost plant growth and yield quantity/quality

BC_Green
BC_Greenstarted grow question 15h ago
I have been reading a lot about plant hormones (particularly auxin and cytokinin, but also gibberellin, abscisic acid, and ethylene). I am curious how, when, and why people use them in the vegetative and flowering phases, and what ppm dose.
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Mr_Weeds_Autos
Mr_Weeds_Autosanswered grow question 8h ago
Sounds like you’re on the right track, digging into plant hormones—it's a deep rabbit hole, but super useful if applied right. In veg, most growers stick to auxins like IBA or NAA for cloning (typically 500–2000 ppm in gels), and some use cytokinins in low doses (1–10 ppm foliar) to promote bushier growth or more lateral branching. If you're looking to stretch tight plants or help stubborn seeds, a bit of GA3 (10–50 ppm) can do the trick—but it’s easy to overdo. For flowering, ethephon is used by some to promote female flowers or help speed up ripening, usually around 150–500 ppm. Cytokinins can be used in flower, too, but they need to be low-dose or you risk getting leafy buds. ABA is more niche, but some advanced growers experiment with it near harvest to signal the plant to finish strong and boost trichome production. It all comes down to that auxin-to-cytokinin ratio—higher auxin leans toward root growth, higher cytokinin toward shoots and branching. Just start low and dial it in slowly if you're experimenting. Most hobbyists don’t go this deep, but for those chasing dialed-in results, hormones can be a game changer.
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oldskoolkool
oldskoolkoolanswered grow question 10h ago
Iv been using a number of plant growth hormones for over 10yrs now in the form of seaweed/kelp.I use it from the second the seed pops through to the 3rd week of flowering. Even some flower boosters like Cannas boost use kelp for mid flowering.Some people soak their seeds in it but Iv never felt the need.Theres certainly a lot to be said for the KISSS aproach.Keep It Simple Stupid.They do very well on very little but a little too much can create problems.I see the most difference in the health and strength of the plants. Check my roots out.I can't really say for sure if they make any difference to the final flower as Iv never compared them but I do get large yields.My last grow was 7 plants with the smallest being just over 7oz and the biggest being just over 8oz.The plants are very strong and vibrant.Iv done several grows with humidity being as high as 80% through flower and Iv never had more than 1 or 2 buds with mold which was due to me missing dead leaves.I would never use man made.I'm pretty sure you can't buy man made growth hormones in the EU but I guess you can in the US as the foodm producers in the US get away with more murders than the ones in the EU.The US use loads of substances that are banned in the EU.I do recommned you keep all nutrition and stimulants organic.The smell and taste is better.
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Green_claws
Green_clawsanswered grow question 12h ago
Use poly20 to mix none water soluble, triacontanol being 1 of those..
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ATLien415
ATLien415answered grow question 12h ago
Firstly, don't artificially mess with ethylene unless for breeding purposes.. Second, you're going to be funning fine on all the hormones you mentioned as long as you have a modern light fixture with an appropriate stage-based spectrum. The only supplemental hormone I mess with is from Grease, their Alpha Grease. Real NIH studies back to back to back on this, the full story is the old Mammoth P (sold as a microbial booster type additive) had insane results to the point they tries to demonstrate in the lab. Turns out, the microbes didn't do a single thing at all but the alphalpha derivatives in the solution, namely triacontanol, were the entire benefit. This is the underlying mechanism for the old agricultural trick of throwing alphalpha next to all your crops. The hormone triacontanol slaps in basically every plant ever. It is essentially an all natural PGR, which if you study up in botany there are laws/theorems relating calyx development and such and anchoring it to other aspects of budding....in other words, most hardcore cultivators hate the synthetic PGRs for what they do to genetic integrity, bud formation, and false pollination issues.... I'm only a month in and my rooms are somewhat dialed in already, so I can't 100% vouch for it in implementation but in theory that is where I landed.
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Ultraviolet
Ultravioletanswered grow question 14h ago
Plant hormones, especially auxins, are not always water-soluble. To ensure proper dissolution and application, alcohol is used as a solvent. Higher % the higher the dissolution. Every plant has a different threshold required to elicit a response, 400ppm is on the high end of the scale for gibberellin in a cannabis plant, rest im not sure. 1g in 1000 ml is 1000ppm, 1g in 2000ml is 500ppm. Can be applied both through roots or foliar. Most of my experience is purely experimental, ABA is something ive had my eye on for a while, ABA forces stomata closed. when RH drops below 20% aba is mass produced. When stomata close, VOC(terpenes) cannot be releassed. Terpene accumulation in plants is primarily triggered by a combination of biotic and abiotic environmental stressors, as well as internal factors. Abiotic stressors like UV radiation, drought, salt, and temperature stress can all induce terpene production and accumulation. In addition, biotic stressors such as insect feeding/defoliation and pathogen attack can also stimulate terpene synthesis as a defense mechanism. Removing all red light from a grow removes the PR-pfr conversion meaning plant will accumulate but will be unable to release. Terpenes where not created so humans could get high and feel chill, terpenes play an important role in nature and especially in plants. among many other things they are responsible for attracting pollinators. Everything has a signal, everything has a trigger all you gotta do is figure out what they are and when best to apply. Not conventional but thats ok, even if it makes 1% difference, one thing i've learned in cannabis growing is those 1% "inches" add up.
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Organic_G
Organic_Ganswered grow question 15h ago
what I know so far ( no expert in plant hormones) At the end everything from seedling, through Veg, Strech, flower etc. Is based on changes in Hormone expression mostly based on DLI (Daily Light Integral) over a period of time, don‘t know about syntetic hormon supplementation but in organic culture we often use Alfalfa & Kelpmeal for hormone push, i don‘t think it‘s the hormones that you can supplement to your plants, rather than the stimulus for the plant to produce more of an certain hormone… what exactly These triggers are & how they express i don‘t know… Why people use it? Crop Steering, shorter or taller plants, more horizontal or Vertical grow, faster bud development over all a better harvest & more control… For example, Far Red Light Waves trigger the Phytochrome System which changes the destribution of Auxine, Gibberelline & Ethylene & results in more vertikal than horizontal growth… Another example, when you do Scrog, like I do currently, you tie down the main stem, normaly Auxin is produced in the top of the main stem, Auxin signal the side branches Not to grow that tall, through scrog the Auxine distrebute throughout the cannopy evenly…
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