How Hormones Affect Cannabis Growth
Quick Summary: Plant hormones like Auxins, Gibberellins, and Cytokinins are natural weed growth hormones that control everything from root stretching to bud density. By mastering these chemical messengers, growers can significantly increase yields, prevent hermaphroditism, and produce top-shelf flower with elite terpene profiles.
How Hormones Affect Cannabis Growth: The Ultimate Technical Guide
How hormones affect cannabis growth is the difference between a hobbyist and a master cultivator. These organic compounds, known as phytohormones, act as the plant’s internal biological clock and software. They signal when to stretch during the vegetative phase, when to stack calyxes during flowering, and how to respond to environmental stress. Mastering these weed enhancers allows you to manipulate the plant’s architecture for maximum light interception and resin production.
Recommended Strains
Cheese
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THC | 14% - 18% (Medium) |
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Type | Feminized |
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Yield | Medium |
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Phenotype | 60% Indica / 40% Sativa |
Cheese Fast Version
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THC | 18% - 20% (Medium) |
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Type | Fast Flowering |
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Yield | High |
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Phenotype | 45% Indica / 55% Sativa |
Phytohormones work in tiny concentrations but have massive effects on the cannabis growth hormone pathways. For instance, the ratio of auxins to cytokinins determines whether your plant grows into a tall “Christmas tree” shape or a bushy hedge. When you buy premium seeds from Blimburn Seeds, you are getting stabilized genetics that have been bred to respond optimally to these hormonal signals, ensuring that your efforts in the grow room translate into heavy, potent harvests.
Promos & Deals
Auxins: The Master Growth Directors
Auxins are the primary weed growth hormones responsible for apical dominance. This is the biological process where the central stem grows more vigorously than the side branches. Auxins are produced in the meristem (the tip) and travel downward, preventing lateral buds from growing. This is why “topping” or pruning the tip of a plant works; it removes the auxin source, allowing cannabis growth hormones to distribute to lower branches, creating a wider canopy.
Beyond height, auxins are critical for root initiation. When you take a clone, auxins accumulate at the wound site to signal the creation of new root cells. Professional growers often use indole-3-butyric acid (IBA) or naphthaleneacetic acid (NAA) as synthetic weed enhancers to speed up this process. Proper auxin management ensures the plant stays oriented toward the light (phototropism) and develops a robust vascular system to transport water and nutrients efficiently.
Gibberellins and Cytokinins: Balancing Vigor and Density
Gibberellins are the gas pedal for cell elongation. During the early vegetative stage, these hormones determine the “internodal distance” or the space between leaves. While essential for overall vigor, an excess of gibberellins can lead to spindly, weak stems that cannot support heavy buds later in life. Balancing light intensity (PAR/PPFD) is the most natural way to regulate gibberellins; low light levels cause the plant to produce more gibberellins as it “stretches” in search of the sun.
Cytokinins are the cell division specialists. While auxins make cells longer, cytokinins make more of them. They are primarily produced in the roots and travel upward. Higher levels of cytokinins promote lateral growth, leading to the bushy structure found in high-yielding Indica strains. By maintaining a healthy root zone with optimal oxygen levels and a pH of 5.8 to 6.2, you encourage natural cytokinin production, which keeps leaves green longer by delaying senescence (aging).
Technical Hormone & Strain Comparison
| Technical Feature | Bruce Banner Auto | Blue Dream | Critical Daddy Purple |
|---|---|---|---|
| Dominant Hormone Response | Ethylene (Rapid Flowering) | Auxins (Strong Vertical Stretch) | Cytokinins (Lateral Bushing) |
| Light Cycle Requirement | 20/4 (Autoflower Vigor) | 12/12 (Photoperiod) | 12/12 (Photoperiod) |
| Internodal Spacing | Compact (High Density) | Spacious (Sativa Influence) | Short (Dense Stacking) |
| Pruning Strategy | Minimal (LST only) | Topping/ScroG (Auxin control) | Lollipoping (Airflow focus) |
| Primary Terpenes | Caryophyllene, Myrcene | Myrcene, Pinene | Linalool, Humulene |
| Typical Yield Potential | 400-500g/m² | 550-650g/m² | 500-600g/m² |
Ethylene and Abscisic Acid: The Harvest Signals
Ethylene is often called the “ripening hormone.” In cannabis, it plays a vital role in sex determination and flower maturation. High stress levels can cause an imbalance in ethylene, leading to the development of male flowers on a female plant (hermaphroditism). To keep ethylene levels stable, avoid sudden temperature swings and ensure your plants are not physically damaged during the peak of the flowering stage.
Abscisic Acid (ABA) is the plant’s stress manager. It controls the opening and closing of the stomata (breathing pores) on the underside of the leaves. When a plant is underwatered, ABA levels spike, forcing the stomata to close to conserve moisture. While this saves the plant’s life, it also stops photosynthesis. This is why how hormones affect cannabis growth is linked directly to your watering schedule, consistent moisture keeps ABA levels low and growth rates high.
Professional Tips for Hormone Manipulation
- Natural Auxin Boost: Use a tea made from sprouted lentils or willow branches. These are packed with natural Indole-3-acetic acid (IAA) and can be used as a powerful, organic cloning dip.
- The “FIM” Technique: By removing only 90% of the apical tip, you leave a complex hormonal “scar” that results in 4 or more main colas instead of just two, effectively multiplying your yield.
- Silica for Stem Strength: While not a hormone, adding Potassium Silicate strengthens the cell walls elongated by gibberellins, preventing the “flopping” of heavy Sativa branches.
- Freshness Matters: Natural “botanical teas” made from nettles or garlic provide fresh brassinosteroids. Use these the same day they are brewed, as these hormones degrade within hours once exposed to air.
- Moderate Application: Never apply concentrated hormonal enhancers more than once a month. Over-stimulation can cause “hormonal burnout,” leading to mutated leaves and stalled growth.
FAQs
How hormones affect cannabis growth in the flowering stage?
During flowering, the plant shifts from producing Auxins and Gibberellins to focusing on Ethylene and Florigen. Florigen is the “flowering signal” triggered by 12 hours of uninterrupted darkness. This shift stops leaf production and directs all energy into calyx development and trichome synthesis. Maintaining a stable environment is key to keeping these hormones balanced for high-potency buds.
What is the best cannabis growth hormone for bigger buds?
Cytokinins are generally considered the best hormones for bud size because they promote cell division in the flower sites. However, you cannot rely on just one. A successful harvest requires a synergy between Cytokinins for density and Auxins for structure. Using organic weed enhancers like seaweed extract is a safe way to boost Cytokinin levels naturally.
Can weed enhancers cause hermaphroditism?
Yes, if used incorrectly. Excessive stress or the application of certain weed growth hormones like Silver Thiosulfate (STS) can inhibit Ethylene, forcing a female plant to produce male pollen sacs. To prevent this, ensure you are using stable genetics from breeders like Blimburn Seeds and keep your environmental stress factors (heat, light leaks) to a minimum.
Does blue light affect weed growth hormones differently than red light?
Absolutely. Blue light (400-500nm) inhibits Gibberellin production, which keeps plants short and prevents stretching. Red light (600-700nm), especially “Far Red,” stimulates Gibberellins and the “shade avoidance response,” causing plants to stretch. Master growers use a mix of both to control the plant’s height and stack nodes closely together for a more efficient harvest.
