4.1 The vegetation phase of cannabis

The growth or vegetative phase of cannabis is a crucial time during which plants grow vigorously and prepare for the flowering phase. During this phase, the plants develop their structure, roots, and leaves. Here are detailed instructions and tips on what to consider during this phase:

1. Light

  • Light cycle: During the vegetative phase, cannabis plants require a light cycle of 18 hours of light and 6 hours of darkness (18/6). Some growers also use a 24-hour light cycle to maximize growth.
  • Light source: Use high-quality LED, HPS, or MH bulbs. LED bulbs are more energy-efficient and generate less heat.
  • Light intensity: Make sure the light source is close enough to the plants to provide sufficient light, but not so close that it causes burns.

2. Nutrients

  • Nitrogen (N): During the vegetative phase, cannabis plants need a lot of nitrogen for leaf growth.
  • Phosphorus (P) and potassium (K): These nutrients are also important, but in smaller amounts than nitrogen.
  • Micronutrients: Make sure your nutrient solution also contains micronutrients such as calcium, magnesium, and iron.
  • Fertilization schedule: Follow a proven fertilization schedule and increase the dosage gradually. Overfertilization can lead to nutrient burn.

3. Irrigation

  • Watering: Water thoroughly until water begins to flow from the drainage holes at the bottom of the pot. Allow the top layer of soil to dry out slightly between waterings.
  • pH: The ideal pH for soil is between 6.0 and 7.0; for hydroponic systems, between 5.5 and 6.5.
  • Water quality: Use filtered or distilled water without chlorine.

4. Temperature and humidity

  • Temperature: Keep the temperature between 22°C and 36°C during the day and between 16°C and 20°C at night.
  • Humidity: Relative humidity should be between 40% and 70% during the vegetative phase. Higher humidity promotes leaf growth.

5. Ventilation

  • Fresh air supply: Ensure your plants receive sufficient fresh air. A fan can help improve air circulation.
  • CO2 supply: Additional CO2 supply can accelerate growth.

6. Pest control

  • Check regularly for pests such as spider mites, thrips, or aphids.
  • Use biological pesticides or neem oil for prevention.

7. Repotting

As your plants grow larger and their roots fill the pot:

  • Repotting into larger containers encourages further root growth.
  • Be careful not to damage the roots when repotting.

Conclusion

The vegetative phase is crucial for the future growth and yield of your cannabis plants. By paying attention to light cycles, nutrients, watering, temperature, humidity, and ventilation, as well as using appropriate training techniques, you can cultivate healthy plants ready for a successful flowering phase.