Key takeaways.

  • Why is night-time important to flowering cannabis plants?

    In the wild, a cannabis plant would typically begin to flower at the first signs of winter (the number of night-time hours increases). This is because they won't survive the winter, and therefore have to pollinate and make seeds to lay dormant in the soil until the following spring. Growers increase the number of dark hours in their grow rooms to trigger the flowering period.

  • What else happens during the flowering stage?

    Cannabis plants begin to produce THC, CBD and terpenes — these are the parts of cannabis that make each strain unique, and are also why humans love cannabis!

  • How long does flowering last?

    Flowering can last between 7-9 weeks, depending on the strain and the seed. It's during this time that the entire cannabinoid profile will be created in the buds.

My Supply Co. is presenting to you our Seed To Smoke Series — a series of articles about the entire life cycle of cannabis. We’re going on a journey from all the potential encapsulated in a cannabis seed to the final product that ends up in dispensaries, in your joint, and moving through your veins.

The Seed To Smoke series covers:

The life cycle of cannabis is wonderfully complex and intricate. It’s one of just a handful of dioecious plants in the world (dioecious; adjective; (of a plant or invertebrate animal) having the male and female reproductive organs in separate individuals). And to think that the entire life cycle of a cannabis plant happens in 4 - 6 months!

In the last article, we talked about vegetation, which is when most of the growing happens. It’s also when growers typically apply their growing techniques. In today’s article, we’re talking about the flowering period and why the night-time is so important to photosynthesis.

Let’s get straight in.

Photosynthesis and the importance of night-time for the flowering stage.

Flowers photosynthesizing during the night-time

In our previous article on vegetation, we talked a little bit about what happens during the light phase of photosynthesis. Chlorophyll does some crazy cool, kind of alien transformation of light and water and carbon dioxide into the energy the plant needs to make sugar. 

In the wild, cannabis plants begin to flower after the winter solstice, which is also when the number of hours of sunlight begins to slowly decrease and the nights get longer. This period represents the onset of winter. As an annual flowering plant, cannabis responds to this by flowering or producing pollen sacks, cross pollinating with other plants and then producing seeds. The seeds lay dormant in the soil until enough warmth and water is in the soil — which is spring the following season!

Knowing that an increase in darkness triggers flowering is how indoor growers trick their plants and force them to start flowering. It also means that something is changing in the plants biochemistry as the night-time hours begin to dominate.

Let’s have a look at them.

In the previous chapter, we mentioned that chloroplasts (specialised cells within the cannabis leaf) convert sunlight, water and carbon dioxide into chemical energy. That chemical energy is a compound called ATP — known in biology as cellular energy.

During the dark hours of a 24-hour period, plant cells use the chemical energy created during the daytime to produce glucose. This happens through a cascade of chemical reactions called the Calvin Cycle (it’s a lot of scientific jargon that we don’t need to get into for the purpose of this article). 

Once glucose has been produced, it is used by cells in a number of other chemical reaction cascades to produce lipids, carbohydrates, and a lot of the stuff we end up consuming as plant eaters. Essentially, these are the products that make up plant tissue. This includes starch, which can actually be transported and converted into cellulose (which is another very complex series of events).

THC and other cannabinoids arrive on the scene

A close up of a cannabis flower

Flowering is when cannabis plants begin to produce THC, CBD, and all the terpenes that make cannabis a plant that humans love. It becomes extremely aromatic during the flowering phase. And obviously, this is when the buds that will finally be consumed develop. 

The length of time a cannabis plant spends flowering differs between varieties. Growth also happens during flowering, and the amount of it also depends on the strain being grown. However, the reason that growers spend time training their plants during vegetation is to train the plant in such a way that when flowering kicks in, all of the plant’s energy can be converted into producing flowers.

Growers do this because flowers are what contain the commercially viable part of the plant — cannabinoids and terpenes. This stage of growth is fundamental to commercial cannabis growers. If something goes wrong during flowering, the entire cannabinoid profile can be disrupted.

Don’t pick flowers at night time — they’re sleeping!

If you’ve ever been slapped on the wrist for picking flowers at night time, this article is why! Cannabis plants, just like humans, never really switch off. Even when you’re sleeping, your brain-computer is actually finalizing all of those calculations and sorting everything out. A lot of work is happening, but it’s the integration.

It’s the same with plants at night time!

Even though they are hard at work converting chemical energy into glucose and other compounds, they’re actually sleeping. They’re integrating all of the energy that was consumed during the day into something real and practical that can be used by the plant. 

We’re finishing off this series with one more article about what happens beyond flowering and harvest. Stick around to see the rest of the journey through the cannabis life cycle from seed to harvest. 

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