Your Guide To Cannabis Flowering

30 November -0001
This stage is when flowers start forming, the buds can underdevelop if we didn't take good care in the stage before.
30 November -0001
10 min read
Your Guide To Cannabis Flowering

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  • 1. The pre-flowering stage week-by-week
  • 1. a. The pre-flowering stage: week 1
  • 1. b. The pre-flowering stage: week 2
  • 1. c. What about autoflowers?
  • 2. The flowering stage
  • 2. a. The flowering stage: week 1
  • 2. b. The flowering stage: week 2
  • 2. c. The flowering stage: week 3
  • 2. d. The flowering stage: week 4
  • 2. e. The flowering stage: week 5
  • 3. In conclusion

The flowering stage consists of the pre-flowering and flowering phases, this is when you see pistils starting to appear on the bud sites all over your cannabis plants and will develop into beautiful looking and smelling flowers that contain what all cannabis consumers love: terpenes and cannabinoids.

This stage is the most important one for us growers, this is when we’ll see the beautiful buds develop and we’ll need to take even more care than in the previous stage.

Unlike in the vegetative stage, when our cannabis plant is flowering it is even more difficult to deal with pests and any other types of deficiencies as this can directly affect our buds, so here's our article about the last of the growing stages of weed.

1. The Pre-Flowering Stage Week-by-Week

After your cannabis plant has received its first days of a 12/12 light cycle either indoor or outdoor, it will enter the pre-flowering stage. Have in mind automatic cannabis doesn’t depend on a light cycle to start flowering and will flower in an 18/6 light cycle.


Your Guide To Cannabis Flowering: Female pre-flowering

Female cannabis plant in the pre-flowering stage.

This means that there isn't the best time to start flowering cannabis in general, if you're growing autos you cannot control it because autos will start flowering automatically but if you're growing photos, the best time would be when they have reached the desired size.

So now that your cannabis plant went through the whole vegetative stage healthy, it’s time to start transitioning into the flowering stage.

The Pre-flowering Stage: Week 1

The pre-flowering stage can take up to 3 weeks, depending on the genetics and growing conditions but in most cases, it will take around 1 week for autoflowering cannabis and around 2 weeks for photoperiodic genetics.

These are the first signs of flowering stage but it’s not the flowering stage per se, it’s seen as the transition from the vegetative stage to the flowering stage.

Just remember that autoflowers will enter the pre-flowering stage automatically while photoperiodic strains need a change in the light cycle to do so, so make sure you know the basics before choosing one or the other.


Your Guide To Cannabis Flowering: Female vs male cannabis plant

First signs of a female vs a male cannabis plant.

Most home growers are not breeders and their goal is to make buds and not seeds so you will see your plant showing signs of its sex. If it’s a female it will start growing pistils, a small number of trichomes and slowly start to smell like a cannabis plant should.

If you’re growing regular seeds, your plant could be a male and it will start to grow pollen sacs.

So If you are growing regular cannabis seeds, that means there's a 50% chance of getting male plants, if you happen to get male plants, instead of the buds starting to swell, you will see the pollen sacs growing and ultimately opening up, looking like typical small flowers.


Your Guide To Cannabis Flowering: Male pollen sacs

Male cannabis pollen sacs completely mature and spreading pollen.

Anyways, now that you know you’re plants are female, you can go ahead and continue the pre-flowering stage without worrying about pollination.

But before seeing any flowers or pre-flowers, the first sign that you have a female plant is the stigmas, also known as white hairs.

These white hairs, as mentioned before, mean that your cannabis plants are female and sexually mature, meaning that your cannabis plants are ready to start producing beautiful buds.


The pre-flowering stage: week 1

The pre-flowering stage: week 1 by lilpete1 and SimpleJack2.

It doesn’t matter if you’re growing photos or autos, the pre-flowering stage will be the same for both types of cannabis plants despite usually taking longer for photoperiodic cannabis. 

Once your plants have shown their sex, the second sign that indicates your cannabis plants are transitioning from veg to flowering is the flowering sites turning into a light bright-green.


The pre-flowering stage: week 1

The pre-flowering stage: week 1 by SimpleJack.

As you can see in the image above, all of the flowering sites turned bright-green, that’s a sign that your plants will start growing a lot of white hairs and that the buds will start to take form in no time.

The Pre-flowering Stage: Week 2

After 1 or 2 weeks, depending if it’s an auto or photo and the genetics, the pre-flowers should look similar to this and when this happens, it means that your plant has completely transitioned to the flowering stage. 


The pre-flowering stage: week 2

The pre-flowering stage: week 2 by SimpleJack.

As your plant develops further into flowering stage it will slowly start absorbing less nitrogen and will start to need more of the other macronutrients, like phosphorus and potassium.

This doesn’t mean you should stop giving it all other nutrients but means you will have to increase the amount of phosphorus and potassium you give her every week to allow her to develop properly.

You will also see her growing a lot, it sometimes can even double its size in a couple of weeks, this is referred to as the “flowering stretch". This happens because your plant wants to develop as much as it can before starting developing what would be her reproductive parts (buds), to guarantee the survival of the species.

The “flowering stretch” solely depends on genetics, sometimes they grow a lot, sometimes not.

What About Autoflowers?

As mentioned before, photoperiodics usually take longer than autoflowers to go through the whole pre-flowering stage but if you’re dealing with autoflowers, there’s no need to worry because despite taking only 1 week, the process is the same and you will see the same signs as your plant develops.

2. The Flowering Stage

Around 2 weeks into the pre-flowering stage, your plant is ready to start the final phase, which is the flowering stage. It doesn’t matter if you’re flowering outdoors or are running an indoor flowering stage, in this stage, you’ll see your plant start to truly develop the buds.

You will slowly see the buds swell, the trichome production going up, and most importantly, the smell starting to become strong.

Depending on the genetics you’re growing, the flowering stage can take from 5-6 weeks up to 10 weeks, so if you were wondering how long is the flowering stage outdoors or indoors? Now you know that it depends on several factors, but mainly genetics.


Your Guide To Cannabis Flowering: Carbon filter

Carbon filter in an indoor cannabis grow room.

Despite the difference in the flowering times you will have to mask the smell to avoid problems, so if you weren’t using anything to mask the smell, this is when you want to invest in an air filter or something similar. In this stage, the smell will be pungent and can attract unwanted attention to your grow room.

This is also when you have to be the most careful with the environment you’re growing in. If you were to get a mold infection or anything else that can harm your plant, this is the worst time to have it happen.

Because the bugs can get stuck on the buds or get inside the buds, you will have a really hard time getting rid of them. For example, ants can get stuck on trichomes and you will have to pick one by one, making it a really hard and laborious task.

The Flowering Stage: Week 1

When your plant officially enters the flowering stage, the buds will start to take form and with bigger buds comes an increased trichome production, this means that if it wasn’t smelling before, your grow tent will start smelling quite strong.

As you see the increase in bud production, you will have to supply your plant with an increased amount of nutrients. Usually, at this stage, your plant can handle a full dose of nutrients or even more but remember to always follow the manufacturer's guidelines because overfeeding can shock your cannabis plants.


The flowering stage: week 1

The flowering stage: week 1 by FastMan.

As you can see in the image above, the buds are far from being ready but they have started taking the shape that we all now, the hairs will still grow a bit more before the calyxes (the parts that make the actual bud) start fattening up.

The Flowering Stage: Week 2

The second week into the flowering stage is when the white hairs start getting long by now the hairs should be all over the place, meaning that you will see a lot of them growing in every direction and in every bud site.


The flowering stage: week 2

The flowering stage: week 2 by FastMan.

Also, this is when the trichomes will start appearing exponentially, your plant and surrounding foliage won’t be as frosty as it will get in the last weeks but you should be able to see the resin on the buds and surrounding foliage with ease.

The Flowering Stage: Week 3

When your cannabis plants reach the middle of the flowering stage, in this case in week 3 of flowering, you will see a huge difference in the buds after every couple of days; This happens because the foundation of the flowers is established so now it’s just a matter of fattening up those beautiful buds.


The flowering stage: week 3

The flowering stage: week 3 by FastMan.

Just by looking at the picture in week 2 and week 4, you can see there’s a huge difference in bud density and amount of trichomes; What last week were hairy buds with not a lot of resin are now relatively fat buds that become frostier due to the increased trichome production and from this point forwards it only gets better.

The Flowering Stage: Week 4

By week 4 of flowering there’s nothing much to say, if you’ve done everything properly the buds should be looking and smelling great, and if you’re keeping a good environment, there’s no much to do. Just keep an eye for bugs and signs of deficiencies but it should be fairly simple by now.


The flowering stage: week 4

The flowering stage: week 4 by FastMan.

Despite looking like they’re completely ready, harvesting now will not only affect the yields (because the buds will get a bit denser) and can end up affecting the effect due to the cannabinoids inside the trichomes not being at their peak potency so make sure you harvest at the right time to truly feel the full potency of the strain you’re growing.

The Flowering Stage: Week 5 

Week 5 of flowering marks the last week of the flowering stage, remember that this is not the case with all cannabis strains, if the genetics you’re growing take a bit longer you can still guide yourself with these pictures but it will take a bit longer for you to see the differences that we're seeing here from one week to the next.


The flowering stage: week 5

The flowering stage: week 5 by FastMan.

During the last days of flowering there’s not much to do other than wait and, if necessary, start the flushing process, this process should be started when the buds dense and there’s no more visible growth from one day to another.

Flushing will allow your cannabis plant to clean itself from the remaining minerals in it and will result in a flower with a better aroma and flavor, you should flush for at least one week before harvesting.


Gorilla Glue Auto on the last weeks of flowering.

Now, you should know that the standard practice for when to harvest is the state of the trichomes; Trichomes can be clear, cloudy or amber, and each one provides a different effect.

Clear trichomes are not completely mature so the effect will not be strong, while cloudy trichomes are at their peak potency that provides a more cerebral effect whereas amber trichome will provide a more corporal effect.


Your Guide To Cannabis Flowering: Different stages of the trichomes

The three different colors of trichomes.

So now that you know when to harvest for the desired effect, make sure your cannabis plants are bug-free and leave them in complete darkness for 48hs. In the meantime, prepare the dry room for the number of plants you will harvest in the following days. After removing them from darkness, they’re ready to be trimmed and harvested.

3. In Conclusion

The marijuana flowering stage is the final and most important of the marijuana growing stages. This is when we’ll see our precious buds developing, we’ll be able to see the buds taking form and feel that delicious smell we’ve been waiting to smell for so long.

Remember that everything that happens in this stage will have a direct impact on the buds themselves, unlike in the vegetative stage. You have to be extra careful because the strong smell not only attracts bugs but also noisy neighbors.

Other than basic care, the weed flowering stage will be fairly simple to look after it. Enjoy taking care of your cannabis plants, keep them healthy and you will enjoy even more when the time to smoke your flowers arrives.