The best part about growing weed is getting to the end when you can finally smoke it! At least, that is how most of us think in the beginning. Later, the act of growing becomes a labor of love, a joyful hobby.

Sometimes I’m even sad when the growth cycle is over and harvest time has arrived; it’s like watching your kid grow up and move away!

But enough of the sentimental stuff. There’s plenty of time for that later once you become a master grower. For now, let’s cut to chase and get down to the numbers:

  • How long does the flowering stage last for marijuana plants?

If you are asking this question, then you have probably discovered that cannabis is a photoperiod plant with two distinct periods, or stages, or growth.

The first stage is the Vegetative Period, and the second stage is the Flowering period. When growing indoors, you, the grower, dictate what stage the plant is in by controlling the light cycles.

This article is about the Flowering stage, and specifically, how long it lasts.

You cannot control how many weeks it takes to flower marijuana indoors

The Flowering Stage is different from the Vegetative Stage in that it’s time frame cannot be extended or manipulated with light cycles.

As we’ve explained before, the indoor grower has complete control over how long the Vegetative Stage lasts indoors. This is because the grower can keep the plant in a vegetative state by simply keeping the light cycle at 18/6.

  • By limiting the amount of darkness the plant receives, it will remain in a vegetative state.
  • The grower can keep the plant in a vegetative state basically forever, which is what happens with a Mother Plant.

However, once you have switched to the 12/12 light cycle, you have initiated the flowering stage, and there is no going back!

How long is the flowering stage when growing indoors?

As stated, once you switch to the 12/12 light cycle, your plant will enter the flowering period. It will eventually bloom, and it will reach peak maturity, at which point you must harvest the plant.

When growing indoors, the flowering stage is measured in terms of weeks or days. This is different from outdoor cultivation, where the flowering stage is typically measured in terms of time of the year.

An example would be a prescription to harvest a strain in late September or early October. An outdoor grower may refer to a strain that should be planted in April or May or June. And then recommend that the strain be harvested at a certain time, such as mid-October or late October.

Outdoor cultivation is all about the geography and seasons.

Indoor cultivation is all about grabbing your stopwatch or your calendar and saying “Go!”

Flowering cannabis indoors is all about tracking the days and weeks, so that you know exactly where the plant is in its flowering cycle, and how many days or weeks it has left. It doesn’t matter what month you started in.

But you must keep a logbook or a calendar. You must document when you switched to the 12/12 light cycle. That is Day 1. From there, you will want to track your growth on a week-by-week basis.

How Many Weeks of Flower until Harvest time when growing indoors?

The average flowering time for most weed strains is 8 to 9 weeks, or 56 to 63 days. But of course, there are some strains that flower in a shorter time frame, as well as other that require more time to reach peak maturity.

Most of the strains that we grow at Smokey Okies are 9-week strains. We typically harvest our plants between Day 60 and Day 63. Though, if we notice a plant is finishing faster, we will take it down sooner rather than waiting on the schedule. We balance what the calendar says with what our eyes can see.

While most modern strains will complete flowering in 8 to 9 weeks, you should know about the different flowering times for other strains.

Flowering times for different strains

Landrace sativas are known to have flowering times that exceed ten weeks. These are the ancient sativa strains that come from tropical areas. Their long flowering time is probably a result of the tropical climate, and the lack of “seasons” that the rest of the world experiences.

But it is not just sativas that can have a longer flowering time. There are many modern strains that require 70 days or ten weeks to complete flowering.

How Long you Flower your Weed Plant also influences the yield

And this makes logical sense if you think about it.

A plant that is harvested after 7 ½ weeks is probably not as big as a plant that is harvested after 10 weeks. So plants that have longer flower times also tend to have larger yields.

Sometimes you can keep a plant in flower longer than necessary, to try and achieve more yield. But if you wait too long, your plant will be overripe and the quality of your final product will suffer.

If you don’t know when to harvest your plant, or if you don’t know how long it has been in flower, then check out this article on when to harvest cannabis plants.

Shortening the flowering stage with LED lights

Sometimes, the flowering stage can be shortened by increasing the amount of PPFD in the room. If you subject your plants to more photons, the plants will experience more development, at a more rapid rate.We have seen this with our Agnetix LED lights. An example would be our Cakes ‘N Cream strain, which will be completely finished in 50 days or so when grown under the Agnetix LED.

We are not exactly sure why, but we subscribe to the theory that higher amounts of PPFD accelerate the maturity phase, or flowering phase, of the plant.


Join our mailing list to receive the latest news and updates from our team.

You have Successfully Subscribed!