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The Vegetative Stage in Marijuana

Everything You Need to Know About the Vegetative Stage

Before your cannabis starts producing its aromatic buds, it goes through various maturity levels. The first and probably most important is the vegetative stage. Cultivating a healthy plant from the onset increases your chances of a bountiful yield.

This post highlights essential aspects regarding this phase of your marijuana plant’s life and how to enhance your chances of a successful crop. Let’s dive right in!

When does the vegetative stage start?

When your seeds have germinated, and your marijuana plant has a stable root system, it will begin producing leaves. Once seven sets of pointed leaves are visible, you can safely say your crop has entered the vegetative stage.

When does the vegetative stage start? It varies from one plant to another but typically starts two to three weeks after germination. It’s at this point that the crops develop the necessary structures for optimal photosynthesis to take place. 

The Vegetative Stage

What is the cannabis vegetative stage?

The cannabis vegetative stage is where growth truly takes off. It’s during this phase of life that it develops vital physiological functionalities. The roots become firmer, and crops fully engage in the task of converting carbon dioxide and light into energy.

What happens in the vegetative stage?

The weed vegetative stage is the time to introduce training to your plant. This phase also has a direct impact on the final yield. 

Growers should ensure that there’s a controlled environment with adequate light and water. Depending on the strain of your crop, you should consider supplementing with appropriate nutrients during the vegetative stage as well.

The most important developments are:

  • The cannabis develops stems
  • Leaves grow

Cannabis develops stems 

Growers usually relocate cannabis plants to a larger area when it reaches the vegetative stage of plant growth. The stems thicken and increase in length. This is essential as it’s the main support structure of your crop. 

The stem is responsible for transporting nutrients and fluid from the roots to the rest of the plant and forms the foundation for the fan leaves and, ultimately, the colas. You will also be able to see new nodes on the stem.

Leaves start to grow

The nodes you’ve previously noticed on the stem will produce new branches and leaves. This is an indication that the vegetative stage has begun in earnest.

Most growers determine that this phase has begun by counting the number of fan leaves present. The more rigid blades each leaf has, the more mature your plant is.

Daily care in the veg stage

The weed vegetative stage is critical for the successful production of buds. Growers need to take extra care with environmental controls and ensure that the plant gets sufficient water and nutrients.

The Vegetative Stage


Water and sunlight are the two main components for vegetative stage weed to photosynthesize actively. You need to ensure that your plant gets an adequate supply but avoid over-watering.

How often should you water the plants?

Increase the water supply to your cannabis crops during the vegetative stage. It’s developing more rapidly than during the seedling phase, and you need to find a balance between over- and under-watering.

You can usually detect if you need to make any changes to the quantities you’re supplying by observing the plant’s structure. Crops that droop and appear limp lack sufficient fluids, and plants that receive too much liquid often have brown leaf edges and curl.

In some instances, too much H2O can also cause the plant to droop, so it’s best to look out for additional symptoms before making any changes. Ideally, it would be best if you established a watering schedule. 

You can use the finger method, where you push a finger an inch into the soil to feel for moisture. If the soil is dry, water it. If it’s wet, wait a day or two. 

Nutrient feeding 

During the vegetative stage, cannabis is susceptible to nutrient deficiencies. Supplements help offset this and facilitate healthy growth. 

Vegetative stage nutrients 

During this important phase, you need to ensure that there are enough cannabis nutrients in the soil. Cannabis requires larger quantities of nitrogen, phosphorus, and potassium (NPK). 

Your primary goal should be to meet the demands of your crops rather than overfeeding. In the early vegetative stage, nutrients should be introduced with the ratio of NPK at 4:3:2. 

As your plant matures, approximately six weeks after germination, you can fertilize more aggressively with the ratio increasing to 10:5:7. During the last week or two of the vegetative stage, you can reduce the nitrogen levels. 

These are rough guidelines, and each fertilizer brand comes with product-specific instructions. Try to opt for organic marijuana nutrients and don’t be excessive in your feeding habits. Observe your plants carefully before making any rapid changes. 

Provide appropriate lighting 

How much light is best for the vegetative stage? The amount of lighting marijuana crops receive during the vegetative stage directly impacts how well it will support the buds. Providing it with sufficient brightness facilitates overall health as well.

The light you supply to your grow area influences how well your plants develop. You need to take note that the required amount differs for photoperiod and autoflowering seedlings, respectively. 

When growing outdoors, photoperiod weed requires a specific amount of sunlight to flourish. This is why the seasons of sowing and harvesting are important. Autoflower varieties, on the other hand, aren’t dependent on light cycles. 

Photoperiod crops enter the flowering stage based on changes in the light cycles. Growers who want to extend the weed plant vegetative stage typically prefer indoor growing as it allows them to have full control over the available lighting.

The Vegetative Stage

How much light for the vegetative stage? 

The ideal amount of light for the cannabis vegetative stage depends on several factors, including genetics. Growers opt for different cycles according to the needs of the plant. 

The most popular option is 18 hours of light followed by six hours of darkness. It’s the cycle most novice growers start with. As they gain experience, they tweak it to suit the specific crop they’re cultivating.

In this phase, it’s essential that the crops don’t get more than 12 hours of darkness as it will trigger the flowering stage to begin. Blue variants are considered the best lights for the vegetative stage.

Get the temperature right

Most cannabis strains flourish in moderately warm temperatures. Crops get burnt in excess heat but also struggle to grow in cold climates. 

What’s the perfect temperature?

During the early stages of development, your vegetative stage cannabis indoors prefers warmer conditions that range between 70℉ and 85℉. You should try to be closer to the cooler end of the range during the dark part of the cycle and warm it up in the light period.

This range changes slightly when your plants enter the flowering phase. 

Air Circulation

During the vegetative stage, marijuana plants need plenty of dry air and CO2. If you’re growing crops indoors, you need to mimic mother nature and give your crops the right amount of airflow. 

Most growers choose to use both inline and oscillating fans. The inline fans extract air from the growing area and introduce outside air. The oscillating ones keep the humidity build-up to a minimum by moving the air around. 

You should adjust the speed of each fan according to the light and dark cycle of the grow space. 

Problems to look out for 

The importance of the vegetative stage has already been highlighted. Any cannabis seedling problems that arise during this period can affect the quality and quantity of buds the crops produce. 

The Vegetative Stage

It’s best to take a preventative approach and take action based on your daily observations. Common problems to check for are: 

  • Stretching 
  • Strange color 
  • Bad smells
  • Falling leaves 
  • Slow growth 
  • Insects
  • Drooping leaves

When you’ve established that something’s wrong, you can quickly diagnose and treat the issue to have minimal long-term effects. 


If the vegetative stage weed has a growth spurt and the stems start stretching, it could result in a tall plant with a relatively weak stem that won’t be able to support the buds once they develop. 

The reasons plants stretch vary, but in some cases, you can offset it by adjusting environmental factors. Some changes you can make are: 

  • Avoid growing your crops too densely.
  • Opt for blue lights instead of yellow and red.
  • Control the temperature between dark and light periods 

Strange coloring 

If your vegetative stage plant is discolored, it could be a sign of a nutrient deficiency. Other issues that result in color changes are: 

  • Plant diseases (bacteria, fungi, or viruses)
  • Underwatering 
  • Overwatering
  • Insufficient light exposure 
  • Excess heat 
  • Excess wind 

Bad smells

It’s normal for your marijuana in its vegetation stage to have an odor, but if the smell is particularly pungent, it could be a sign of stagnant air. This can result in mold or fungus. Try improving the air circulation to reduce this issue.

Leaves dropping off

Losing a few leaves shouldn’t be cause for concern, but if it’s a daily occurrence, you have a serious issue. Some reasons for this could be: 

  • Nitrogen deficiency 
  • Excessive light exposure 
  • Excess phosphorus 
  • Fungus gnats 
  • Insufficient grow space 

The most common way of fixing this is by flushing, followed by supplying your crops with the appropriate marijuana nutrients.

Slow growth

The vegetative stage should be a period of continuous – and in some cases – rapid growth. If development has slowed down, the possible causes are:

  • Incorrect amount of light exposure
  • Incorrect light spectrum
  • Light cycle interruption
  • Overwatering 
  • Nutrient deficiency
  • Incorrect ph level
  • Incorrect temperature
  • Plant parts that are too big

The only way to accurately diagnose the cause is to observe your cannabis and apply a method of trial and error.


The problem with insects on your plant is that they don’t only eat the parts, but they also excrete on your crops, which creates a breeding ground for mold. You can get rid of this problem by routinely spraying your crops and ensuring adequate airflow in your grow room. 

Common marijuana pests are:

  • Cabbage loopers
  • Mites 
  • Thrips
  • Aphids 
  • Leaf miners 

Drooping leaves

The good news is that drooping cannabis is curable if you act swiftly. Your first course of action is to assess how you’ve been watering your plants. Overwatering and underwatering both cause drooping leaves. 

To determine which is the culprit in your specific case, you need to look at additional symptoms. If the leaves are also shriveling and withering, dehydration is probably the cause. 

If, on the other hand, your leaves are firm, but curling and the tips are turning yellow, excess H2O is likely to blame. You can use a soil sensor to measure the moisture in the dirt to avoid future issues.

The Vegetative Stage

How long does the vegetative stage last 

The vegetative stage starts about two to three weeks after germination and can last between three to 16 weeks. The duration depends on several factors such as plant genetics and the goals of the grower. 

Those who cultivate indoors sometimes opt to extend the phase. A plant that emerges from the vegetative stage in good health will be able to withstand the weight of a bountiful yield. 

How to know when you should flip to flower 

Timing is key if you want to generate a generous supply of buds. If the crops are allowed to flower too soon, it will result in an unimpressive yield. 

Subsequently, if you wait too long, you could end up with burnt buds. The main aspects to consider regarding flowering cannabis are: 

  • Height of the plant
  • Cannabis strain
  • Growing setup
  • Clones or seeds 

Clones tend to gain height quickly, resulting in growers flipping to flower sooner. Certain strains develop better if left in the vegetative stage for longer. 

It’s all based on the crop you grow, but the vegetative stage length shouldn’t exceed sixteen weeks. 

Nipping the bud

The cannabis vegetative stage has many aspects that are plant-specific and details regarding optimal conditions vary from one grower to the next. The main thing all marijuana enthusiasts agree on is that this phase of maturity is vital for producing healthy buds. 

When growing your weed, keep an eye on the environmental factors, provide it with adequate cannabis nutrients and observe your plant’s health as it matures. 
The only way to find the ideal vegetative stage conditions for you is by cultivating and making changes according to your plant’s needs. Check out our seed store to get started and track your crop’s progress as it grows.

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