The Cannabis Flowering Stage

GTA Seeds
22 hours ago
3 min read

The Cannabis Flowering Stage: What Growers Need to Know for Big, Resinous Buds

After weeks of nurturing your cannabis plants through the vegetative stage, you’re finally entering the flowering stage — the most exciting and critical phase of your grow. This is when your plants shift energy into producing buds, rich with cannabinoids like THC and CBD, as well as those aromatic terpenes we all love.

But the flowering stage isn’t just about watching your plants bloom — it requires precise care, observation, and the right environment to maximize quality and yield.

In this blog post, we’ll break down:

What triggers flowering
The different stages within flowering
Environmental needs
Nutrient requirements
Common issues and tips for success

🕒 What Triggers the Flowering Stage?

Cannabis is a photoperiod plant, meaning it starts to flower when the light cycle changes — typically from 18/6 (light/dark) during veg to 12/12 during flower.

For outdoor growers, this shift happens naturally as days get shorter toward late summer. Indoor growers must simulate this by adjusting their grow lights.

Note: Autoflowering strains will begin flowering automatically after 3–5 weeks regardless of light cycle.

🌀 The Phases of Flowering

The flowering stage lasts anywhere from 7 to 12+ weeks, depending on strain genetics (indicas generally flower faster than sativas). Here's a breakdown:

🏁 Week 1–2: Transition (Pre-Flower)

The plant undergoes a growth spurt, often doubling in size — this is known as the “flower stretch.”
White pistils (hairs) appear at nodes — the first sign of flowering.
Plants are still building structure; support and training may be needed.

To-do:

Switch to 12/12 light cycle (indoor).
Begin feeding with bloom nutrients, reducing nitrogen slightly.
Install trellises or netting if needed for support.

🌼 Week 3–4: Early Flower Development

Small budlets form where pistils were.
Trichome production begins — your plant starts making cannabinoids and terpenes.
Stretching slows down, and the plant diverts energy to flowers.

To-do:

Increase phosphorus and potassium for bud formation.
Monitor for pests and humidity (mold risk rises).
Light defoliation may help with airflow and bud light exposure.

💎 Week 5–7: Bud Fattening

Buds get noticeably thicker and resin production increases.
Aromas intensify — your grow space starts to smell like the strain’s signature scent.
The plant's energy focuses fully on flower development.

To-do:

Keep nutrients consistent, especially PK boosters.
Watch for nutrient burn or deficiencies.
Maintain low humidity (40–50%) to prevent mold.

🔍 Week 8–10+: Ripening and Maturity

Buds reach peak density and potency.
Pistils darken and curl inward.
Trichomes turn from clear to milky, then amber — a key sign of maturity.

To-do:

Start flushing your plants with plain water (last 1–2 weeks) to remove excess nutrients and improve taste.
Examine trichomes under a loupe:
- Milky = peak THC
- Amber = more CBN, calming effect
- Clear = not ready yet
Prepare for harvest once ~70% of pistils have darkened and trichomes are mostly cloudy.
Ready to Harvest Cannabis Plant

🔧 Environmental Needs During Flowering

Factor	Ideal Range
Light Cycle	12 hours light / 12 hours dark
Humidity	40–50% (lower in late flower)
Temperature	68–78°F (20–25°C) day, slightly cooler at night
Airflow	Strong circulation to prevent mold
Light Intensity	High-quality, full-spectrum light

Pro Tip: Absolute darkness during lights-off is critical. Light leaks can stress plants and cause hermaphroditism (plants growing both male and female parts).

🧪 Nutrients for Flowering Cannabis

Switch from vegetative nutrients (high in nitrogen) to bloom nutrients, which are higher in:

Phosphorus (P) – For bud formation
Potassium (K) – For overall plant health and trichome production
Calcium & Magnesium – Vital for dense flowers and avoiding deficiencies

Flush your medium with pH-balanced water in the final week or two to ensure smooth, clean-tasting buds.

🚫 Common Flowering Stage Problems

Issue	Cause	Fix
Bud rot (Botrytis)	High humidity, poor airflow	Lower RH, increase circulation, defoliate
Nutrient burn	Overfeeding with bloom nutrients	Reduce dosage, flush soil
Light burn	Lights too close to canopy	Raise lights, reduce intensity
Hermaphroditism	Stress from light leaks, heat, genetics	Eliminate stressors, check genetics

🧠 Final Thoughts: Patience Pays in the Flowering Stage

The flowering stage is the most rewarding yet fragile period in cannabis cultivation. By understanding the different phases, fine-tuning your environment, and closely monitoring your plants, you can maximize trichome production, flavor, and potency.

The key is to observe and adapt. Every strain behaves differently, but by following these flowering best practices, you’ll be well on your way to a bountiful, sticky, and aromatic harvest.