—orig. developed through MOICANNA
– originally developed through MOICANNA
—orig. developed through MOICANNA
– originally developed through MOICANNA
In cannabis cultivation, unpredictable situations can arise that demand immediate attention. Whether it’s a power outage, pest infestation, nutrient burn, or environmental imbalance, your ability to act swiftly and effectively can mean the difference between salvaging a healthy crop or facing significant losses. This guide is a quick reference to help you make informed decisions during such critical moments, ensuring your plants stay on track.
| Leaves curling upward | Cause | Heat stress |
| Action | Increase airflow with fans, reduce light intensity, or raise lights further from the canopy. | |
| Yellowing leaves (lower) | Cause | Nitrogen deficiency |
| Action | Apply a nitrogen-rich fertiliser and adjust pH for proper nutrient uptake. | |
| Yellowing leaves (upper) | Cause | Iron or sulphur deficiency |
| Action | Apply chelated iron or sulphur-rich supplements and adjust pH to the optimal range (soil: 6.0–6.5; coco: 5.7–6.2, and hydro: 5.5–6.0). | |
| Sudden leaf drop | Cause | Overwatering or underwatering |
| Action | Adjust watering practices; let the medium dry out for overwatering, or rehydrate slowly if underwatered. | |
| Brown spots on leaves | Cause | Calcium deficiency or pest damage |
| Action | Apply Cal-Mag supplements if nutrient-related; inspect for pests like thrips or spider mites and treat accordingly. | |
| Wilting stems | Cause | Root rot |
| Action | Improve drainage, apply hydrogen peroxide (3%) to the roots, and ensure proper aeration. | |
| White powdery film on leaves | Cause | Powdery mildew |
| Action | Remove affected areas, increase airflow, reduce humidity, and treat with potassium bicarbonate or neem oil spray. | |
| Burnt tips of leaves | Cause | Nutrient burn |
| Action | Flush the growing medium with clean, pH-balanced water; reduce the strength of the nutrient solution by 50%. |
| Winter | PROBLEM | Sudden temperature drops |
| Action | Use space heaters or insulated grow tents to maintain at least 18°C (65°F). Ensure proper ventilation to avoid condensation. | |
| Problem | Low ambient humidity | |
| Action | Add a humidifier or place damp towels in the grow room to maintain humidity. | |
| Summer | Problem | Heatwaves |
| Action | Increase air circulation with fans, reduce light intensity, and consider running lights during cooler night hours. | |
| Problem | High ambient humidity | |
| Action | Essential for resolving imbalances in nutrient uptake. |
| Portable fans | Purpose | Emergency airflow | Keep plants cool during equipment failures or heatwaves. |
| Battery-powered LED lights | Purpose | Emergency lighting | Ensure the light cycle isn’t disrupted during power outages. |
| pH adjustment kits | Purpose | Quick pH correction | Essential for resolving imbalances in nutrient uptake. |
| Spare pumps and duct fans | Purpose | Backup for hydroponic systems and airflow | Prevent extended downtime due to equipment failure. |
| Sticky traps | Purpose | Pest control | Monitor for infestations like fungus gnats or thrips. |
Νοταε
Topics
emergency, decisions, crisis, nutrients, pests, environment, equipment
Focus Keyword
cannabis emergency cultivation decisions
Description
Something is happening right now and you need an answer. Environmental emergencies, nutrient crises, pest outbreaks, equipment failures — structured responses for when there is no time to read.
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The VADEMECUM is becoming a living archive of guides, tools, notes and practical plant knowledge.
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Keep the
archive open.
The VADEMECUM is not just a book anymore. It is becoming a living archive of guides, tools, notes and practical plant knowledge.
Free member access. Join early. Keep the archive open.
The VADEMECUM is becoming a living archive of practical plant knowledge.
Free member access.