Cannabis Flowering Stages Week by Week (With Pictures)

Cannabis Flowering Stages Week by Week

The cannabis plant, commonly known as marijuana or weed plant, is something that has been cultivated for thousands of years and has been a part of many ancient cultures and civilizations. Some have used it for its medicinal benefits while there have been others who have consumed it to just get ‘high’ off it. The same usage pattern continues even today as these are still the two reasons as to why weed is grown today. However, in these modern times, we know much more about growing cannabis than we ever had. We now know the different phases of the plant’s growth cycle and how to provide it with ‘optimal conditions’ so that we can get the maximum possible output out of the plants. With this knowledge in mind, in this article, we shall be taking a closer look at the cannabis flowering stages week by week – how they grow and what are the things that growers need to take care of. 

The cannabis plant goes through seven different stages of growth between being a seed and being harvested. We shall begin by taking a look at all the stages but then turn our attention towards the topic at hand, which is the flowering phase. There, we shall look at a week-by-week progress of how flowering happens in a plant. Generally, this flowering phase can last for about eight to nine weeks and we shall be taking you through a detailed week-by-week progress of the plant. Let us now begin by first understanding what the different phases are:

What are the Different Stages of Growth for a Cannabis Plant?

When it comes to growing a marijuana plant, the journey starts at the humble little seed. The seed you buy needs to be feminized. You can get specially feminized seeds from various ‘seed banks’ which are going to ensure that you get the right kind of seeds for growing your plants. Once you get your seeds, you then need to germinate them by first immersing them in water for a while and then keeping them wrapped in a damp cloth in a dark room. Once the germination process is complete you’ll see that a solitary sprout has popped out of the seed which is the ‘taproot’. 

Once the taproot has emerged, you know that the seed now needs to be placed in the soil. Put it in the soil with the taproot facing downwards and make use of a sprayer to spray some water on to the soil so that it remains moist and eventually you will see that a small shoot starts to grow out of the soil. That means your plant has now entered the seedling stage and this is where it is the weakest and needs a lot of care. You will have some very small leaves coming out of the plant in this phase. A temperature of about 73F is good for the growth of the seedling and they need a lot of light. About 18 hours of lighting and 6 hours of darkness every day. 

Post germination the plants start growing and becoming taller at a rather rapid pace, which is the fourth phase after seed, germination and seedling – the stage of vegetative growth. Here, you need to provide lights which are on the bluer spectrum, and the plant would need lighting for about 16 hours a day during this time. This is followed by the pre-flowering stage where you will be able to determine the gender of the plant as sex organs begin to show up. In case there are any male plants now is the time to seperate them. When you lower the lighting from 16 to 12 hours, you enter into the flowering stage. Let us now take a detailed look at the cannabis flowering stages week by week:

Cannabis Flowering Stages: A Week By Week Look

Weeks 1-3: 

Weeks 1-3

In the first three weeks of the flowering process, you will start off by reducing the photoperiod down to 12 hours. This tricks the plants into believing that it is the winter period (hence the shorter days). This is still a time period where you will see that the vegetative growth continues to increase and the height of the plant goes upto double, or sometimes even taller than that. Many people call it the ‘stretch’ phase and this is a good time to ‘train’ your plant under low stress training methods, if you wish to. Newer buds will begin to form now.

Weeks 3-4:

Weeks 3-4

This is the next step which starts off as the buds start to emerge. Over these two weeks you will notice that a large number of buds are popping up while some leaves on the bottom will start looking paler/yellow in color. You don’t really need to worry about the lower leaves as this is something that is bound to happen. However, what should not be happening is that your upper leaves must not get a nutrient burn.  Watch out for the pigmentation and the texture of the upper bunch of leaves in the plant, and see if they are showing any changes to the color – sometimes the tips might turn brown due to this. In case this is happening you will need to reduce the nutrients you are providing to the plant. This is also a good time to check the plant’s bodies for any other infections. 

Weeks 4-6:

Weeks 4-6

The small budlets from the previous phase are now going to mature and flatten out. At this point your plants have attained the maximum height and growth and are no longer going to grow taller or bushier. New buds are also unlikely to develop now so  you can stop your training process if you are still continuing with it. At this point new leaves will also not grow so you might want to remove the leaves on the bottom which aren’t really doing great and have turned pale or yellow in color. You might want to consider defoliating those leaves but remember to do it only if you have some prior experience in doing so else you might end up damaging the plant and adding more stress on to it during an already stressful time. 

Week 6-8:

Week 6-8

In this stage your beds will fully mature and will begin to ripen. All your plants energy and resources will be pointed towards ensuring the buds ripen properly. You will notice that these buds are getting really large by this point in time and this is the time that you stop providing all the nutrients that you are. This will help flush the plant so that excess nutrient gets drained off while residue nutrient is consumed by the plant. Some leaves will begin to fall off (if you haven’t already defoliated them). Also raise the lights higher because buds are fragile and can suffer light burns. Also increase the air flow and reduce the temperatures. 

Week 8 and Beyond:

Week 8 and Beyond

By this time your flowering process has almost come to an end. This opens a one-week harvest window beyond which the THC content would start to degrade and it would form CBN which is not as potent. The smell coming from the plants will be the strongest at this point in time and buds will start gaining a lot of weight – sometimes making it very hard for the branches to carry them and branches will begin to droop. This is where the harvest ideally begins and the flowering stage comes to an end. 

Things That Need to be Taken Care Of During Flowering

  • Lighting- You need to make sure that you are providing the right kind of light, and also from the right distance. During the flowering stage, the light needs to be lowered and brought closer to the plants depending on setup to setup. Usually this drop is from 24 inches during the vegetative phase to 18 inches in the flowering phase. The lighting also needs to be kept on for a specific amount of time – shorter hours when compared to the previous phases. Flowering plants need about 12 hours of light and the kind of lighting that they need is towards the red-end of the spectrum (warm lighting).
  • Air CirculationA proper air circulation is critical for the plants, especially at the flowering stage. While it brings in a fresh supply of oxygen and other elements that the plants need, another great thing that having a steady breeze does is that it ensures that temperatures remain cool. It helps the accumulated hot air disperse off.
  • NutrientsFlowering is the time that the plants need a lot of energy as all their resources are spent on the development of the flowers. You will notice that other portions such as leaves etc start wilting and drooping while the flowers bloom. This is because all the nutrients are used in developing the flowers. Plants need an excess supply of nutrition at this point in time which you can provide by mixing it with water. A low nitrogen solution is usually provided to plants during this phase.
  • Keeping Pests AwayIt is at this stage that the plants are very vulnerable to pets and insects as colors begin to brighten up on certain parts of the plant’s body and attract a lot of unwanted attention bringing insects and pests near them which might damage the plant. Hence you need to make sure your plants are growing in a pest-free environment.
  • HumidityHumidity levels in the flowering stage need to be lowered. This is helpful because by doing so, you will make sure that your plants are sucking in more water from the roots than directly from the leaves. Water intake from the roots is important because this is how the nutrients get into the body of the plant.
  • TemperatureWhile temperatures during the growth phase can be a little hotter (about 70-85F – 20-30C), you will need to cool it down a little during the flowering stage as heat is bad for the flowers. Ideal temperatures for the flowering stage of the marijuana plant vary between 65 to 80F, which is about 18 to 26C. 

Frequently Asked Questions About the Cannabis Flowering Stage

Here are the answers to some frequently asked questions about the flowering stage of the cannabis plant:

1. Which is the Best Grow Light for Flowering Phases of the Marijuana Plant?

Any grow light would work but it is preferred to use one which has a reddish tint. A full spectrum LED grow light which will allow you to switch to the red spectrum and covers sufficient area to provide lighting to all your plants will suit your needs the best.

2. Why does lowering lighting help push the plant into the flowering stage?

Traditionally the plant blooms in winter – and hence when the photoperiod is lowered it is tricked into believing that it is wintertime out there (even if you are growing indoors). Reducing the photoperiod kickstarts flowering in the marijuana plant but this might be different for different kinds of plants.

3. What are auto-flowering plants?

Autoflowering plants have a different kind of a genetic structure which ensures that the plants enter the flowering stage without really having to alter their photoperiod. They can enter flowering after a fixed amount of time without reducing the lighting hours to 12.

4. What’s next after flowering?

As flowering approaches an end, you will need to begin the flushing process. Here you basically ensure that excess nutrients are drained off the plant’s body. Then the harvesting, curing and processing phases begin – following which you finally get to smoke the bud you have been growing for so long!


We hope that this article about the cannabis flowering stages helped you get a detailed understanding of what flowering is and how it works. The cannabis plant is not a complex being and it grows rather comfortably indoors with minimal care and attention needed. You just need to give it the perfect conditions and you can be assured of good growth. We hope that this article helped you understand the plant better. If you still have any questions or if you feel that there’s something that we might have missed out on, drop us a mail or let us know in the comments below and we shall get back to you soon. Till then…

….Happy Growing! 🙂



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