If your cannabis seedling has only one visible leaf, there are several possible causes and steps you can take to address the issue:
### Causes:
1. **Genetic Anomalies**: Sometimes, genetic issues can cause unusual growth patterns in seedlings.
2. **Environmental Stress**: Too much or too little water, incorrect temperature, poor lighting, or nutrient deficiencies can affect growth.
3. **Poor Germination Conditions**: Uneven moisture or an unclean germination environment can hinder development.
4. **Pests or Diseases**: Fungal, bacterial infections, or pests can stunt growth.
### Steps to Address the Issue:
1. **Check Growing Conditions**:
- **Light**: Ensure your seedling is receiving adequate and consistent light. A good LED grow light can help.
- **Temperature and Humidity**: Maintain a temperature around 20-25°C (68-77°F) and humidity levels between 50-70%.
- **Watering**: Water the seedling regularly but avoid waterlogging. The substrate should be slightly moist but not wet.
- **Nutrients**: Use a light nutrient solution specifically designed for seedlings.
2. **Inspect for Pests and Diseases**:
- Examine the leaves and stem for signs of pests such as spider mites or aphids.
- Look for discoloration or spots that might indicate fungal or bacterial infections.
3. **Be Patient**: Sometimes seedlings just need a bit more time to develop. Give your plant a chance before deciding to start over.
By carefully monitoring and adjusting these factors, you can give your cannabis seedling the best chance to grow healthily.