Should be useful to growers 
new and experience.
Common Cannabis Plant Problems and Solutions: Seedling to Flowering Guide
Introduction
Growing cannabis successfully means not just knowing how to nurture healthy plants—but also being ready when things go wrong. Different growth stages bring unique vulnerabilities. This guide walks you through the typical problems by growth phase, explains what the symptoms mean, identifies causes, and provides actionable solutions. Whether you’re in the seedling, vegetative, flowering, or late-flowering stage, you’ll find clear troubleshooting steps to keep your crop on track.
Common Cannabis Plant Problems and Solutions in the Seedling Stage
Healthy Seedling Characteristics:
- 4–6 deep green serrated leaves.
- Sturdy and upright plant.
- No signs of pests or diseases.
| Symptom | Example Picture | Cause | Solution |
| Stem grows tall, weak, and thin |
| Insufficient light | Increase light intensity; support the seedling if it falls. |
| Damping off: Thin stem, seedling wilts |
| Fungal attack on roots or stem | Prevention is key. Avoid overwatering and use well-draining soil. Unfortunately, affected plants usually cannot recover. |
| Leaf edges yellow |
| Excessive light | Reduce light intensity or increase the distance between the light source and the plant. |
| Leaf edges curl upwards |
| High temperature | Reduce temperature. |
| Drooping leaves and yellow foliage |
| Overwatering | Water less frequently; use a well-draining soil mix. |
| Wilting leaves, dry substrate |
| Underwatering | Increase watering frequency. |
| Leaf tips burned, curled upwards |
| Excessive nutrients in solution | Lower nutrient concentration in feeding solutions. |
Common Cannabis Plant Problems and Solutions in the Vegetative Stage
Healthy Vegetative Plant Characteristics:
- Dark green leaves.
- Sturdy, thick stems.
- Vigorous and upright growth.
| Symptom | Example Picture | Cause | Solution |
| Leaf edges turning yellow and wither |
| Excessive light | Reduce light intensity or increase the distance between the light source and the plant. |
| Leaf edges curl upwards |
| High temperature | Reduce temperature. |
| Drooping leaves, yellow foliage |
| Overwatering | Water less frequently; use well-draining soil. |
| Wilting leaves, dry substrate |
| Underwatering | Increase watering frequency. |
| Brown spots on middle or lower leaves |
| pH fluctuations | Maintain soil/nutrient solution pH between 5.5–6.5. |
| burned tips, curled leaves |
| Excessive nutrients | Lower nutrient concentration in feeding solutions. |
| Yellowing leaves, stunted growth |
| Nutrient deficiencies | Supplement missing nutrients based on specific deficiencies. |
| Powdery mildew (white or gray powder on leaves) |
| High humidity, poor airflow, overcrowding | Remove affected leaves; reduce humidity; ensure proper airflow; prune overcrowded leaves. |
| Root rot (roots brown, slimy; plant wilts) |
| Overwatering, poor drainage | Water appropriately; use well-draining soil. |
Common Cannabis Plant Problems and Solutions in the Flowering Stage
Healthy Flowering Plant Characteristics:
- Narrow, dark green leaves.
- Thick stems.
- Formation of flower buds on branch tops.
| Symptom | Example Picture | Cause | Solution |
| Leaf edges turning yellow and wither |
| Excessive light | Reduce light intensity or increase the distance between the light source and the plant. |
| Leaf edges curl upwards |
| High temperature | Reduce temperature. |
| Drooping leaves, yellow foliage |
| Overwatering | Water less frequently; use well-draining soil. |
| Wilting leaves, dry substrate |
| Underwatering | Increase watering frequency. |
| Brown spots on middle or lower leaves |
| pH fluctuations | Maintain soil/nutrient solution pH between 5.5–6.5. |
| Powdery mildew (white or gray powder on leaves) |
| High humidity, poor airflow, overcrowding | Remove affected leaves; reduce humidity; ensure proper airflow; prune overcrowded leaves. |
| Root rot (roots brown, slimy; plant wilts) |
| Overwatering, poor drainage | Water appropriately; use well-draining soil. |
| Bud rot (rotting flower buds) |
| High humidity, poor airflow | Remove affected buds; reduce humidity; improve ventilation. |
Common Cannabis Plant Problems and Solutions in the Late Flowering Stage
| Symptom | Example Picture | Cause | Solution |
| Buds turn white, leaves brown/crispy |
| Excessive light | Reduce light intensity or increase the distance between the light source and the plant. |
| Normal yellowing of leaves |
| Natural aging or flushing stage | No action needed; this is normal as the plant prepares for harvest. |
Common Pests and Diseases in Cannabis Cultivation
| Pest | Signs | Cause | Solution |
| Aphids | Found on stems and leaf undersides; causes yellowing or wilting leaves
| External contamination or unsanitized grow area | Remove infected parts; apply biological pesticides; introduce ladybugs. |
| Spider mites | Fine webbing on leaves; leaves wilt and die
| Poor sanitation; high temperature, low humidity | Remove infected parts; apply biological pesticides; introduce predatory mites. |
| Whiteflies | Found on leaf undersides; sap-sucking leads to yellow, wilted leaves
| Poor sanitation | Remove infected parts; apply biological pesticides; use sticky traps. |
| Thrips | White spots on leaves; leaves yellow and wilt
| Poor sanitation | Remove infected parts; apply biological pesticides; use sticky traps. |
| Fungus gnats | Small black flies; larvae damage roots
| Damp soil | Apply biological pesticides; use sticky traps; keep soil surface dry. |
Conclusion
When you run into trouble with your cannabis plants, knowing which growth stage you’re in and what symptoms to look for is half the battle. With this guide, you’ve got a clear roadmap: from seedling through late flowering, each stage with its typical problems, causes and solutions. Keep your environment stable (light, temperature, humidity, pH), prioritize drainage and root health, and stay on top of pests and nutrient status. The better you manage the early stages, the smoother the flowering and harvest will be.
