All you need to know about cannabis flowering stages

A week-by-week breakdown of this cycle prepares you to get out there and grow your own plants

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When it comes to growing your own weed, it’s important that you understand a cannabis plant’s flowering stages. Learning about this process helps you get the most out of your plants, and can actually be interesting and fun!  

So what is the flowering cycle?

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The flowering cycle happens immediately after the preflowering phase. The process does not have a specific length of time tied to it, as it’s different for every strain. The genetics of the plant in question are often what determines how long the cycle lasts. The average cycle of an indica dominant strain is about eight weeks, whereas the timeline of a sativa dominant averages out at around 10. In rarer cases, sativa strains have been known to flower for up to 16 weeks, double that of the indica dominant. 

When do plants start to flower?

The flowering cycle begins when cannabis plants start to receive less sunlight. This is a natural process that can be timed, but many growers prefer indoor cultivation because it isn’t restricted by natural timelines. Indoor growers will lower the amount of light time the plants receive when they wish to do so. Typically, the earliest an indoor grower will reduce light time is around a week into vegetative growth. Outdoor growers will have to wait until midsummer, when the days begin to get shorter. 

The flowering cycle by week

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  • Week 1
    • The first week of the flowering cycle starts when the plants begin to grow a lot slower. As previously mentioned, this first week begins when the amount of light the plants receive is reduced. 
  • Week 2
    • In the second week, small flowers should begin to appear on your plants. These flowers will grow on the nodes. 
  • Week 3
    • This week represents the last time the plant will grow any larger. You can expect the plant to be about 25 percent bigger than it was in Week 1. It should not get any bigger than this. 
  • Week 4
    • At this point, the vegetative growth of your plant is done. The only growth from here on will be in harvestable buds. 
  • Week 5
    • During Week 5, you’ll notice that flowers have begun to bloom very quickly. The flowers that began to grow in Week 2 will rapidly expand, and any empty space on the plant will soon be taken up by them. 
  • Week 6
    • If you’re growing fast-flowering plants, Week 6 is typically when you’ll want to harvest them. If not, keep the process going. Week 6 is when you’ll notice (on regular plants) that the areas around the plant’s calyxes have begun to swell. 
    • You will also notice that your plants develop an intense smell. 
  • Week 7
    • During Week 7 the calyxes should begin to produce resin. This is the point in the cycle where you’ll see signs of maturity in each and every flower. 
    • In some faster-growing plants, you’ll see that pistils have already begun to develop on the buds. 
  • Week 8
    • Week 8 is the average point of completion for most indica dominant strains. 
    • Your buds should have deep red and orange pistils. 
    • Your buds are likely to be coated in a very thick layer of trichomes. These trichomes are likely to be covered in resin. Be careful when handling the plants in this stage, as the trichomes may irritate your skin because of the heavy layer of resin. 
    • Please note that if you do not harvest indica dominant strains at this point in the cycle, they will begin to go bad. They’ll deteriorate rapidly and die. 
  • Weeks 9 – 12
    • Most sativa dominant strains will be ready for harvest during these last few weeks. 
    • Some sativa dominant strains may last up to 16 weeks, so be prepared for outliers. 

How much light will suffice during the flowering cycle?

During the flowering cycle, your plants will need 12 hours of light and 12 hours of darkness. This ratio will start and maintain the cycle. Use a light within the red and yellow colour band. This will maximize your plant’s potential, and make the flowering cycle a whole lot easier to maintain. Outdoor growers: make sure your plants get as much sun as possible. It’s not as easy for you, because you obviously can’t control the sun, but it’ll save you a whole bunch of money! 

Nutrient requirements

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Each of your plants needs a healthy amount of the following nutrients in order to achieve its full potential.

  • Nitrogen
  • Potassium (very important)
  • Phosphorus (very important)

Try to avoid using a lot of pesticides.

Final thoughts

Now that you have the basics of the cannabis flowering cycle, it’s time to get out there and grow your plants, knowing you’re prepared. Keep in mind, however, that growing cannabis is not entirely legal in many places. Do your research on the legalities in your area before continuing!

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