Cannabis Flowering Stages: Week-by-Week Guide
The flowering stage is when cannabis plants shift from growing leaves and stems to producing buds. This phase is triggered when plants receive long, uninterrupted periods of darkness, which signals a hormonal change.
While every strain grows differently, most flowering cycles last 7–10 weeks. Here’s what typically happens each week.
🌱 Week 1 of Flowering – The Transition Phase
It may not be apparent but when you change your lights to 12/12 your plant will undergo a huge hormonal shift. You may not see any clear signs of “flowering” but the plant will begin to rapidly stretch upwards.
As the plant begins flowering you will switch over to bloom nutrients. Its always advised to give the growing medium a light flush with water. This will clear out any salts that may have build up or any excess nitrogen left over from veg.
What to expect:
- Rapid vertical growth (“the stretch”)
- Tops begin to flatten slightly (“crowning”)
- Leaves may grow faster than usual
The plant is redirecting energy from vegetative growth toward future bud production.
🌱 Week 2 – Early Bud Formation
At the start of week 2 its more than likely that your plant will still be stretching. There will also be a more prominent crowning on the tops as they begin to set buds. These buds will only be small but should be covered in perfectly white pistols.
Visible signs:
- Small bud sites begin forming
- White pistils (hair-like structures) appear
- Plant structure becomes more defined
This is when the plant clearly shows it has entered the flowering phase. It is also important that during these first 2 weeks after your flush you should not overfeed your plants. Every strain is different but starting with 50% of the recommended dose on the bottle is a good start point. You can then gradually increase the strength of the feed as the weeks progress.
🌱 Week 3 – Bud Sites Develop
In week 3 there will be a few resin glands starting to form on the flower. This gives us a small glimpse of what the future holds for this particular plant. While they may not be actual trichomes they are what will produce them later. This means they are a good indicator of the level of frost you can expect.
What happens now:
- Bud sites become more noticeable
- Calyxes start stacking
- Early resin glands may begin forming
- Aroma starts to develop
This is the first week many growers notice a stronger cannabis smell.
🌱 Week 4 – Flower Production Speeds Up
As you move into week 4 of flowering the vigorous stretching will have ended. The plant will now be able to focus all of its energy into flowering. As a result of this you will see huge changes in your plant over the next few weeks.
Key changes:
- Buds start thickening
- More pistils appear at each site
- Resin production increases
- Aroma becomes much stronger
This is when plants clearly shift from “forming buds” to “building buds.” Buds will start to show on various bud sites around the plant. Over the coming days and weeks you will see your bud density continue to increase as you get nearer to your harvest date. The odor will become a lot more noticeable towards the end of week 4 as the plant begins to produce capitate trichomes.
🌱 Week 5 – Bud Swelling Begins
As you move into the fifth week of the flowering process you will notice a sharp increase in bud production. As the plant is done with its stretching phase there wont be any new bud sites appearing. However in this week the existing bud sites will begin to swell.
What to expect:
- Buds become denser
- Trichome production increases
- Strong, distinct strain aroma develops
The plant’s energy is now dedicated to producing cannabinoids and terpenes. As a result the odor will also increase so make sure you have a good ventilation system to combat any strong odors.
🌱 Weeks 6–7 – Resin & Density Increase
At some point during this 2 week period you may notice your pistols starting to shrivel up and turn a reddish brown color. This means the plants are roughly 3 weeks away from maturity give or take a few days
Common developments:
- Noticeable swelling of buds
- Pistils may begin darkening and curling inward
- Heavy trichome coverage (“frosty” appearance)
- Very strong smell
The plant is reaching peak resin production during this stage.
🌱 Weeks 8–10 – Ripening & Maturity
Your plants will continue to put on a lot of weight during these last few weeks as they near maturity. They will need to be flushed during this period. To check if your plant is ready for harvest inspect the trichomes with a magnifying lens. If the majority of the trichomes are opaque this indicates that your plant is very close to harvest. Amber trichomes are the next stage and when we are at about 65-75% amber we will harvest the plant.
Signs a plant is nearing harvest:
- Many pistils darken and retract
- Buds feel firm and dense
- Trichomes turn from clear → milky → amber
Milky trichomes generally indicate peak THC levels, while more amber trichomes are associated with more sedative effects.
🌿 How Long Does Flowering Take?
- Indica-dominant strains: Often 7–9 weeks
- Sativa-dominant strains: May take 9–12+ weeks
Always check the expected flowering time for your specific strain, as genetics play a major role.
🌞 What Triggers Flowering?
Cannabis enters flowering when it receives extended periods of uninterrupted darkness each day. This change signals the plant to stop focusing on leaf growth and start producing flowers.
🌸 Key Takeaways
✔ Flowering usually lasts 7–10 weeks
✔ Early weeks focus on stretch and bud site formation
✔ Middle weeks build bud size and resin
✔ Late weeks are for ripening and potency development
✔ Trichome color is one of the best indicators of maturity
❓ Flowering Stage FAQs
When do buds start forming?
Usually around weeks 2–3 of flowering.
Why is my plant stretching so much early on?
This is a natural response called “the stretch” as the plant transitions into flowering.
When does the smell get strong?
Most plants develop a noticeable aroma around weeks 4–5.
How do you know when buds are mature?
Maturity is often judged by bud density, pistil changes, and trichome color.
To ensure that your cannabis plant fulfills its maximum potential during its flowering period you need to make sure that your external factors such as the light you use, or the specific color spectrum you choose, are perfect for your plant. For more information on how a specific color spectrum affects your plant during flowering then click the link below.