The flower stage is an exciting time! You started this journey by planting clones or seeds, and then growing your plants through the vegetative stage. Now, you are in the phase where you actually get to watch your buds bloom.

If you are new to growing, you may asking yourself how long will it be until your plant has buds. We wrote a previous article that focused more on bud development.  We explained that the flowering sites don’t really resemble what you would think of as a “bud” until around Week 4, and more so in Week 5.

In this article, we will focus more on the early signs of flowering, by discussing:

  • The anatomy of the plant
  • The early signs of flowering
  • The post-veg/pre-flower stretch period
  • When the flower begins to swell into actual “bud” development

Cannabis Plant Anatomy

It’s helpful to first understand the different parts of the plant. Beginning with a stem that grows vertically from the roots, you have branches that will grow out from the sides. These branches will have various nodes, which are the sides for future flower development. And from the nodes, you will have fan leaves which act as solar panels for the plant.

What is a Flower on a cannabis plant?

In the most basic sense, it’s really just an unfertilized seed pod. Let me explain.

Day 6 of flowering under 12/12 lighting

The nodes which eventually from the flowers/buds, consist of pistils and stigmas, which are the hairs you have have seen. These “hairs” are actually reproductive organs that catch pollen floating through the air.

Attached to these pistils are the bracts, the finger-like protrusions that pair with the calyxes to form what we visually see as being the “bud.” However, these bracts/calyxes are what encapsulate the fertilized egg from the captured pollen.

The flower is part of the reproductive system of the cannabis plant. Therefore, if you are looking for the first signs of flowering, you are looking for development of these reproductive organs.

Of course, our goal is to have non-pregnant female plants that produce flowers to be dried and cured. We definitely don’t want to open our buds to find dozens of seeds!

The First Signs of Flowering are Subtle changes in the nodes

The very first signs are subtle. But if you pay attention, you will see the hints.

About as 8 to 12 days into the 12/12 light cycle, you will see early-stage flower set in on the nodes — the parts of the plant that form the basis of all new growth. From these nodes, all new branches, stems, leaves, and flowers are formed and grow outward.

When looking for early signs of flower, you will first notice when “hairs” poking out of these nodes. From there, they eventually begin forming calyxes. Once these calyxes have formed, there will be what are essentially seed pods.

It is at this time that you can actually identify a male from a female, by looking for an additional set of pollen sacs that will have dropped from the calyx formation on the node. Growers often joke that males have a “nut sack” resembling a set of testicles. When you see these hanging down, you know you have a male.

These signs of early-stage flowering usually occur in Week 2 and more so in Week 3. By the third week, the pistil hairs are much more prominent, and visually obvious even from a distance. By the fourth week, even more development has occurred, and the entire formation begins “swelling” to resemble more of a “bud” shape.

As these reproductive organs continue to develop, they will form what become your “buds” or flowers.

The most obvious sign of early-stage flowering is the stretch

A more obvious sign that your plant is in the flowering stage is when you notice it stretching and growing longer and taller. Some refer to this as the “post-vegetative” stretch, or the “pre-flowering” stretch. Either way, this phenomenon occurs after switching the light cycle to 12/12.

When you walk in and see your plants have suddenly poked through your trellis netting, or are growing wild, you know that you are in the pre-flower stretch period. This period will last about two to three weeks, and during this time, your plant may double or triple in height.

Once the stretch period ends, your plants are ready begin blooming within their newfound growth.

The bracts enlarge to form buds on the plants

Eventually, the stretch period will end. The plants will still continue to grow. But the vertical growth will be much less dramatic. Instead, the plants will funnel their energy into blooming the flowers.

Week 4 of flowering

By Week 4, the development is much greater than what you saw in Week 2. The stretch should be coming to an end, and the bud sites should look much more like buds.

In Week 5, you will begin to see the nodal spacing begin to really fill in, forming colas, where the buds just start running into each other. This is also when the branches become really firm and stiff, no longer pliable like they were in the vegetative stage or early flowering.


The early signs of flowering begin to appear in the second week of 12/12 lighting. Development of the reproductive organs can be seen 8 to 12 days in. During this time, the plant will also be going through its stretching phase. As the stretching slows down, the flower development will begin to accelerate and mature.

To learn more, check out our Week by Week Guide to Flowering Cannabis.



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