Medically Reviewed by
Jason Crawford

Article Last Updated on December 29, 2022

Cannabis cultivation has been done for so long now, that it wouldn’t be wrong to say it has turned into an art form. The methods of growing weed have been perfected over time, and both experienced and new growers now have many resources of information.

Cannabis plants go through several phases of growth and they all have their own specific durations. The vegetative state is one of the most important phases of the life cycle of marijuana plants because it determines the strength and quality of the crops later on.

Keeping the crops happy during the veg phase ensures cultivators will get a bountiful yield at harvest, so let’s talk a bit about how long the vegetative stage should last and what you should do to make the best of it.

Introduction to the Vegetative Stage of Cannabis Plants

The vegetative stage of the growing cycle of cannabis is the phase between the germination and flowering stages.

As soon as the cannabis seeds germinate, they sprout from the soil. The young seedlings will then start growing and developing until their first leaves form. For the following 2-3 weeks, they will start maturing and producing fan leaves and develop larger stems. Fan leaves are large and are therefore crucial for photosynthesis and the plant’s survival. Once the fan leaves have developed, the vegetative stage has started.

What Happens During the Vegging Stage

During the vegging stage, the cannabis plant grows rapidly – the root systems develop further in the soil and work to form a stable foundation for the plant (and take up all the necessary nutrients from the soil). The stalks and stems expand and grow thicker, and the fan leaves develop and grow as well, reaching far and wide, and converting light and carbon dioxide into energy. 

In a nutshell, it’s a very dynamic phase for the plants and they need more attention than ever. The veg state is vital, and unless you provide the ideal environmental conditions for your crops to thrive, your harvest will be poor. 

That said, the cannabis crops will have great demands during this stage. Supplying your crops with adequate amounts of light, water, and nutrients should be your focus during this phase. Happy plants will grow quickly, they will be bigger and will develop more bud sites, and bigger plants with lots of bud sites make bountiful yields.

How Long Does the Veg State Last?

Depending on the genetics of your cannabis plants, the veg time can be anywhere between 3 to 16 weeks, and sometimes even longer. Photoperiod cannabis plants end their vegging state when the light cycle starts to get shorter, and then they start flowering. 

For plants grown outdoors, the natural light cycle dictates when the flowering stage will begin – this happens when summer transitions into autumn, while for indoor plants the light cycle is shorter. Indoor growers have control of the lighting schedule and they usually set it to 12 hours of light and 12 hours of darkness, which initiates the flowering stage. Autoflowering plants, on the other hand, don’t follow any lighting schedule, but they start flowering based on their age.

All cannabis strains tend to grow very quickly during this phase, so they need a lot of room for growth. They are always repotted into bigger containers as soon as the veg stage starts. Indica strains remain stout and grow in width, while Sativa strains tend to grow in height.

Indoor vs Outdoor Growing

Growing cannabis indoors and outdoors are both very different growing environments that require different approaches. However, there is one common rule that applies to both of them and that is – in order to get the best out of your plants and set the foundation for successful CBD and THC development, you need to meet the primary needs of your plants the best way you can. Everything else is just fine-tuning.


Indoor growing gives you complete control over the environment and you can also choose your growing medium (soil or soilless). Plants are usually grown in grow rooms or grow tents, using grow lights and various different devices that control the temperature and humidity in the grow space. As a grower, this allows you to control the veg stage and induce the flowering stage on demand. 

Additionally, having control over the lighting schedule means that the longer you expose your crops to light, the more they can photosynthesize, which means the vegetative growth will be much bigger. This will mean there will be more to handle, but it will also be more abundant.


Growing weed outdoors means that nature will control the growing conditions. Often, this can be a positive thing, especially if you live in a climate that’s good for cannabis cultivation. With outdoor growing, the goal is to boost your plants’ resilience as much as you can, because they will be exposed to wind, rain, humidity, and pests, all of which can affect their vegetative growth. The plant size can’t vary much, as with indoor plants, but it doesn’t mean that its quality won’t be good.

Tips to Make Vegging Even Better

  1. Nutrition – during the vegetative stage, the most important nutrients for your plants are: nitrogen for the stems and leaves, potassium for the production of energy, magnesium for photosynthesis, and calcium for strong cells;
  1. Airflow – proper airflow is very important as excess moisture in the air can lead to the development of mold, so having constant fresh air is recommended. Using extractor fans will help, and they will also bring more carbon dioxide into the room and remove excess oxygen;
  1. Spacing – cannabis plants grow like crazy during the vegging phase, so they will need a lot of space, otherwise, they will get stunted and will block out light from each other. Therefore, spacing them using different methods can help to keep them in order as well as calculating how many plants to grow per square meter. Knowing the size of your weed garden will help you make it more manageable for yourself;
  1. Sexing – sexing the plants is vital if your goal is to produce sticky buds laden with cannabinoids. Removing the male plants on time will stop them from pollinating the female plants during the flowering stage and giving you seedy weed. Sexing the plants is usually done 4 weeks after the germination process when the male and female plants have produced their pre-flowers.


The vegging stage is an important phase of the marijuana plant’s life cycle as it’s the stage when most of the plant’s roots and foliage will develop (which will set the course for the flowering stage). As the veg stage is very dynamic and demanding, your main job as a cultivator is to meet the needs of your crops. How long the veg stage will be, depends largely on the genetics of the plant and also on whether you cultivate your crops indoors or outdoors.

A passionate advocate for the benefits of cannabis. Fraser Horton, who has a background in botany and a strong love of nature, has spent years researching how cannabis affects the body and mind. He established Leaf Nation in 2020, where he has devoted himself to educating people about the legalisation of marijuana and its safe and responsible use. Fraser is committed to highlighting cannabis’ potential for improving wellness and working to dispel the stigma associated with its use.


The information presented on this page is provided as a public service to aid in education and is derived from sources believed to be reliable. Readers are responsible for making their own assessment of the topics discussed here. In no event shall Leaf Nation be held reliable for any injury, loss or damage that could happen if using or abusing drugs.