Understanding growth phases: Germination to harvest

Understanding and optimising cannabis growth phases:

**Germination phase (0-1 week):**

*Physiological processes:*

- Seed absorbs water and swells

- Enzyme activation starts metabolism

- Taproot breaks through seed coat

- Cotyledons unfold

- First true leaves develop

*Optimal conditions:*

- Temperature: 20-25°C constant

- Humidity: 70-90%

- Low light or darkness

- Constant humidity, not oversaturated

- Sterile environment important

*Common problems:*

- Too cold temperatures delay germination

- Overwatering leads to root rot

- Too dry conditions stop process

- Poor seed quality

**Seedling phase (1-3 weeks):**

*Development characteristics:*

- First true leaves with 3-5 fingers

- Taproot develops lateral roots

- Photosynthesis begins properly

- Growth slow but steady

- Very sensitive to stress

*Care requirements:*

- Soft light: 200-400 PPFD

- pH value: 6.0-6.5 (soil)

- Low nutrients: EC 0.4-0.8

- High humidity: 65-70%

- Careful watering

*Critical factors:*

- Over-fertilisation is fatal

- Avoid transplant stress

- Prevent damping-off

- Consistent humidity

**Vegetative phase (3-8+ weeks):**

*Growth characteristics:*

- Explosive growth in height and width

- Leaves develop more fingers (7-11)

- Strong root and stem development

- Lateral shoots develop

- Sexual sign possible

*Optimisation:*

- Light cycle: 18/6 or 20/4

- Light intensity: 400-600 PPFD

- Nutrients: Nitrogen-emphasised (NPK 3-1-2)

- pH value: 6.0-6.5 (soil), 5.5-6.0 (hydro)

- EC value: 0.8-1.4

*Training options:*

- LST (Low Stress Training)

- Topping and FIMing

- SCROG preparation

- Defoliation for dense growth

- Supercropping for experienced growers

**Pre-flowering phase (1-2 weeks):**

*Transition signals:*

- Change light cycle to 12/12

- Internode spacing increases

- First signs of sexing

- Growth slowdown

- Hormonal change

*Adaptations:*

- Nutrient switch to flowering fertiliser

- Increase phosphorus content

- Slowly reduce nitrogen

- Reduce humidity to 50-60%

- Finalise last training

*Critical decisions:*

- Identify male plants

- Final defoliation

- SCROG net final position

- Start flowering fertiliser programme

**Flowering phase (6-12 weeks):**

*Development stages:*

*Week 1-3 (stretching):*

- Height growth 50-200%

- Internodes elongate

- First flowering plants

- Sex clearly recognisable

*Week 3-5 (flower formation):*

- Flower clusters develop

- White pistils appear

- Trichomes begin to form

- Odour becomes more intense

*Week 5-8 (flower development):*

- Flowers swell massively

- Trichomes become milky

- Pistils turn brown in colour

- Peak THC production

*Week 8+ (ripening):*

- Flowers reach final size

- Trichomes turn amber in colour

- Leaves turn yellow naturally

- Harvest time determination

*Environmental control:*