The Perfect Grow, Ep. 8: Flowering Cannabis

Soft Secrets
09 Mar 2023

In the eight chapter of the Soft Secrets’ Perfect Grow series, our dear friend and grow expert Drew Anger walks us through the most important aspects you need to know when Cannabis plants enter their flowering phase. How to set up the lights during this time? Should you go for more trimming? What about feeding, watering and regulating humidity? The Perfect Grow has been brought to you in collaboration with some of the biggest names in the industry, including Royal Queen Seeds. Watch the latest episode and the rest of the series on our YouTube channel and don’t forget to subscribe.

What Happens When Cannabis Enters Flowering?

During vegetation, Cannabis plants generally grow a lot of branches and leaves and ultimately become larger in size. When Cannabis is flowering, the plants stop focusing their energy on growing and redirect all that effort into developing the big sticky flowers that are offering us a smoking enjoyment.

The biological reason for Cannabis flowering is of course reproduction. Basically, the flowers of cannabis plants can be fertilized by catching pollen from male plants, which is how seeds are created. However, selective breeding has helped us to create bigger, fatter, stickier, and more potent buds, and also keep the male plants away from the garden so that the buds are completely seed-free, and so that we can get a little high or a little medicine.

How Do We Control the Flowering Cycle?

If the seeds are auto-flower, they will follow a certain kind of schedule from the moment they are planted and this will not depend on how you regulate the lights. If the seeds are photoperiods, and in most cases they are, including the ones used for this grow project, they will require a switch in the light schedule, causing the Cannabis to start flowering.

The typical lighting regime for cannabis plants in the vegetation phase is 18 hours of light and 6 hours of darkness. During the start of the Cannabis flowering, first and foremost the lighting schedule will need to change. Keep the lights on for 12 hours and then off for another 12 hours. This will enable the flowering Cannabis plants to focus on growing their buds.

The 12-12 lighting schedule triggers the natural response in the plant that winter is coming and that it’s time to start reproducing. After you switch off the lights, the plants won’t immediately start to show flowers. It will take up to ten days before you notice a little white hair starting to form where the buds will eventually be. That white hair is called pistils and it’s part of the reproductive system in female cannabis plants.

Two weeks into flowering, a lot more of white hair will appear and this is the beginning when some buds start to form. Flipping your cannabis plants to flower is easy as that, and in about six to eight weeks, these plants will be ready to harvest. Still, the work doesn’t stop here just because plants have entered flowering. There are some key steps to follow in this stage of the growth process, too.

Useful Tips for Cannabis in Flower Phase

Key steps for when your Cannabis is flowering

In the first few weeks of your cannabis flowering, the plants can literally double or even triple their size. This stretch will finish when the plants start to show flowers, and from this point on, the plants will retain the same size until the very end. The only thing that will keep on growing will be the buds. This is the perfect time to go around the plants and do one more final lollipopping and clear out any excess of vegetation and leaves.

With the final trimming, you want to remove any foul branches in the lower parts of the plant. Take off the branches that aren’t reaching the top of the plant. Also, take out nodes that are covered with lots of vegetation and aren’t getting any good exposure to light. If you leave those lower nodes, they will only produce unusable buds in the end. When you take them out, you again help the plant redirect energy on the bud sites that remain until the end.

At the same time, you can do some defoliation. This is simply removing some fan leaves to allow the light to penetrate deeper into the canopy. You can use snips if you want to or you can do it by hand. Target those fan leaves that are shading large buds underneath them.

Other Important Information for the Flowering Stage

  • Watering: 2-3 liters every other day
  • Nutrients: Continue to follow the schedule given by the brand that you’re using
  • pH value: Keep in the range between 6.0 and 6.5
  • Lights: Gradually increase from 80% intensity to 100%
  • Humidity: Keep around 50%, then reduce to 40%



Be sure to check out all the other articles and videos from The Perfect Grow Series:

How to Set Up A Growing Tent for Weed
Picking the Best Seed from the Best Weed Strains
How to Germinate Cannabis Seeds
The Best Soil for Weed
What Growing Lights to Choose
The Vegetative Stage of Weed

You can watch the full episode below. Due to an age restriction, the video might only be played within YouTube:

Soft Secrets