Cannabis Stages of Flowering

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When growing medicinal marijuana, it is important to know when your plants reach the flowering stage. At this stage of growth, your plants will require a completely different regimen than the vegetative stage.

In fact, the flowering stage can last from 7 to 9 weeks or more. During this time, it is extremely imperative that your plants get the proper care.

Not only do your plants require different lighting than the vegetative stage, but they also need a different amount of nutrients. In fact, your plants during the flowering stage will be more prone to issues.

Frankly, everything that happens from the beginning flowering stage will greatly affect your yields.

Cannabis Flowering Stages

Cannabis goes through not just 1 flowering stage, but several stages. In fact, each week is different from the previous 7 day period.

It is important to provide the proper conditions to each flowering stage for the best plant health and yields.

Week 1-3: Transition to Flowering

One of the first things a grower needs to do during the first three weeks of the flowering stage is to reduce the photoperiod to 12 hours. This tricks your plants into thinking that it is the start of the winter season.

Automatically, your plants will think that the days are shorter. You will notice that vegetative growth will continue to increase.

Cannabis Stages of Flowering

In fact, many plants will double in size and sometimes grow taller. This is a low-stress time for your plants and opportune time to train them.

The common grower term for the training stage is called the “stretch” phase. In addition, at this time new buds will start to grow.

Week 3-4: Budlets Form

During weeks three and four the buds start to appear. Actually, there will be numerous buds that emerge. In addition, many of the bottom eaves will yellow and look pale.

The leaves yellowing at not something to worry about, it is a normal process during this stage. However, you need to watch the upper leaves and make sure they do not have signs of nutrient burn.

If your plants have nutrient burn it is a good indicator that they are getting to many nutrients. As a result, the plant’s health suffers and yields can be drastically reduced.

image showing marijuana buds

In fact, sometimes the shock of nutrient burn can kill a plant. There are several signs to look for

  • Leaves are yellow
  • Leaf pigmentation
  • Tips of leaves turn brown
  • Texture of leaves change

If you suspect nutrient burn, you need to reduce the nutrient intake of your plants. In addition, check for possible bugs or fungus issues.

Week 4-6: Buds Start Fattening

At this stage, the tiny budlets from the previous phase will start to mature. The budlets will also flatten out.

In addition, your plants will have reached their maximum growth in height and bushiness. As well, budlets will quit forming.

In fact, all growth has stopped including new leaves. As a result, training your plants is no longer needed at this time Instead; the focus is on removing the yellow and discolored leaves on the bottom.

Close-up bud marijuana bubble gum on black background

At this stage, many experienced growers defoliate the leaves on the plant. This is a strategic technique is believed to increase yields.

However, not all growers believe defoliation is good for the plants. In fact, many feel that it puts too much stress on the plants.

Nonetheless, only defoliate if you are experienced, otherwise, you could drastically harm or even kill your plants.

Week 6-8: Buds Ripen, Pistils Darken

During this flowering phase, the buds are fully mature and start to ripen. All the plant’s energy is directed to making certain that the buds ripen correctly.

In effect, the buds get a lot larger. Once you notice a huge difference in the size of bud, you need to stop providing your plants with nutrients.

This helps flush your plants by draining off excess nutrients. In the meantime, residue nutrients are consumed by the plant.

A female cannabis flower

Other essential plant health maintenance includes

  • Airflow needs to be increased
  • The temperature needs to be lower
  • All yellowed leaves need to be removed
  • Lights should be raised higher to prevent burning the buds

Week 8+: Flowering Ends, Final Flush, Harvest

By week 8, the flowering process is nearly complete. At this time you have about one week time frame to harvest the buds.

If you go beyond the peak of bud performance, the THC levels begin to decline. As well,, the buds start to form CBN (cannabinol ) which is not as strong as THC.

Marijuana flower blooming medical cannabis plant

Knowing when to harvest the buds is crucial. Generally, the smell is a big giveaway.

The bud order is usually much stronger. In addition, the buds gain a lot of weight.

In fact, the branches can have a hard time carrying the buds and will start to droop. It is at this time that you want to harvest your buds.

When Are Cannabis Plants Ready for Harvest?

Aside from your plants having large oversized buds, there are other ways to determine when to harvest. You can actually use a small microscope or jeweler’s loupe to check the plant’s trichomes.

Trichomes are the resin glands of a marijuana plant that contain THC. A good indicator that the THC is at their highest is when most of the trichomes have an amber color with a milky clarity.

If the trichomes are clear or white in color, then it is too early for harvest.

Experienced growers use two different techniques that help them identify when the buds are ready to harvest.

Another way to identify whether your plants are ready for harvest is by the Pistol Method. The pistol method includes visually looking at the pistols of the plant.

If the pistols or hairs are still white and sticks straight out. You want to harvest when the hairs have darkened and are curled in.

What Do Cannabis Plants Look Like in the Beginning Stages of Flowering?

When the flowering stage begins, your plants will start to make some big changes. First off, your plants will start growing at a much faster rate.

In fact, your plants will double or even triple in size. This is the time to support your plants so that they can hold the extra weight of the buds when they are fully mature.

Marijuana flower buds

Next, your plants will start to form budlets. In addition, the bottom leaves of the plants will begin to discolor by turning yellow or brownish at the tips.

As well, there will be single leaves that start to bunch up at the top of the main colas (the central flower cluster). Pistils will also emerge from the center of the bunched leaves.

This is actually new buds forming.

When Does the Flowering Stage Begin?

The flowering stage is miss-labeled. This stage starts before the plant form flowers or buds.

Actually, flowering occurs about 2 weeks after the beginning of the first stage.

The flowering stage starts when the marijuana plants have a change in light. However, a common misconception is that the change occurs because of less light.

Frankly, the change happens when the plants are exposed to a certain amount of darkness, depending on the strain.

How to Trigger the Flowering Stage – Changing Light Cycle from 18/6 to 12/12

Although changing to a 12/12 cycle is relatively simple, there are actually a few techniques in starting the process. Many growers suggest that you allow your plants to stay in complete and continual darkness for 36 hours.

This causes the PFR (the active form of phytochrome) to drop substantially which in turn sends a strong signal to the plants to flower.

Autoflowering Strains

When it comes to the flowering process, Autoflowering strains are the exception.

In actual fact, they don’t require unceasing darkness to start the flowering stage. On the other hand, they begin the flowering stage after a certain amount of time.

Marijuana flower blooming medical cannabis plant

Additionally, auto-flowering strains grow a lot faster than typical strains. Generally, the vegetative stage lasts 3-4 weeks, then the flowering stage begins.

Nutrients needed during the Start of the Flowering Stage

Once your plants have entered the flowering stage, you need to pay special attention to the nutrients you feed your plants. Many growers agree that the two main nutrients for the flowering stage are phosphorus and potassium (PK nutrients).

During the start of budding, your plants will need enough nutrients to help support all the fast changes as it prepares for budding. However, be very careful about the amount of nutrients.

Man smelling Cannabis plant

Avoid increasing the extra nutrients to quickly. Many growers also recommended that you decrease the nitrogen content. Just be careful to not decrease the nitrogen too soon.

It takes a lot of effort and energy for your plants to flower. In effect, your plants will be extra sensitive to their environment and the nutrients.

You also have to watch out for infestations of pests and disease.

For optimum results, keep a close eye on your plants for any nutrient burns on the leaves. If your plants have any adverse conditions, adjust the nutrient accordingly.

Maintaining Healthy Plants during Flowering

When your plants are trying to form buds, they should look very healthy, lush, and green. If they don’t look healthy, your harvest will not be of high quality.

If your plants show signs of leaf discoloration then they are most likely nutrient deficient. Yellowing leaves is a sign that your plants need nitrogen.

The best nutrient solution for your plants is one that is specifically made for flowering. Use the flowering formula for the first month of flowering.

Keep the same formula, at least until there are signs of flowering such as many pistils and stamens.

Growing sativa and indica strains indoor

You also need to be real careful and not overfeed your plants. As well, nutrients should never be used during the last few weeks of flowering.

This could easily cause nutrient burn.

If your plants lose a few leaves, it is not usually a reason for concern. If they start losing a lot of leaves in a short amount of time, then you are probably giving them too many nutrients.

Training during the Start of the Flowering Stage

It is very important to train your plants so that you get optimum production. The best time to train your plants is during the first month of flowering.

This is because the stems are more flexible during this stage. Training techniques are fairly easy. The most important method is to avoid over-stressing your plants.

Carefully bend the stems to where you want them to grow. Experienced growers recommend that you bend and train the stems to grow in an outward direction and not just grow straight up.

Purple cannabis sativa plant close up

Not only does this type of training offer an even and flat canopy for your plants, but it also gives your plants more light for better production.

Never train your plants after the first month of flowering. The stems are too woody, hard to train, and can easily break. Los stress training is ideal and can actually increase your yields by up to 40%.

Flushing your Cannabis Plants

One of the most important techniques of pre-harvesting your bud is to flush your plants. Generally, flushing is done about 2 weeks prior to harvesting.

Basically, you stop giving your plant nutrient when you water them. This will remove all excess nutrients.

In addition, it will force your plants to absorb all the needed nutrients for the buds. For the most part, the remaining

Flowering Stages Made Easy

When you know the different flowering stages of your plants, it’s easy to encourage optimum health and growth. In addition, if great care is taken with each flowering stage, your yields will substantially increase.

In fact, knowing the stages of flowering is quite beneficial for all growers.