Can You Grow Cannabis in a 3 Gallon Pot

When you think of growing cannabis, you may imagine a sprawling field with rows and rows of plants; the way vegetables are grown. But if you didn’t have space or the know-how to successfully tend to a larger field of outdoor cannabis plants, you may wonder if you can grow cannabis in containers. 

Cannabis can grow in 3-gallon pots. In the case of cannabis, the rule of thumb is, on average, you can grow one foot of plant for every gallon. If you are okay with only growing a 3-foot plant, then a 3-gallon pot will be just fine. 

Now after learning that, if your mind is already reeling with more questions and curiosities, keep on reading to learn more!

Growing Cannabis in a 3-Gallon Pot

It has become common knowledge that the size of the pot your plant lives in will reflect the size that it will be able to grow. As mentioned above, the rule of thumb is one foot of plant for every gallon of container. 

A plant can only grow as big as the pot will allow because the roots of the plant need space. Once they run out of space inside the growing medium of the pot, the plant itself tends to stop growing. 

That is why smaller plants are happy in small pots and why larger plants require bigger pots to grow to their full potential. 

If you are growing indoors, or have limited space, then growing in 3-gallon pots may be the ideal scenario. If you have more space or require larger cannabis plants, then you might consider growing in a larger pot. 

Somewhere in the 5-gallon ballpark should suffice. Any larger, and you’ll begin to run out of room and begin contending with the ceiling. However, if you are outdoors, then, by all means, head for the clouds! 

How Often Should I Be Watering Cannabis in 3-gallon Pots?

The amount you should be watering your cannabis plant is, unfortunately, a tricky variable to get exactly perfect. I know we would all prefer a convenient answer, but every plant and every environment that plant is growing is different. 

For lack of a better explanation, it all depends. 

The good news is that we do know what your watering schedule may depend on

So, when it comes to your unique situation, consider these components when dialing in your customized watering schedule: 

  • Strain of plant
  • Type of growing medium
  • Size of pot 
  • Stage of plant growth 
  • Temperature 
  • Humidity 

When you do decide to water, it seems that common practice is to go for a good heavy soaking. You want to avoid leaving dry spots and make sure to water until you see water beginning to drain out of the bottom. Don’t forget drainage holes! 

From there, you’ll want to observe how long your plant takes to drain and how long the growing medium takes to dry out. Then you can make adjustments accordingly. 

How Big of a Plant Can Grow in a 3-gallon Pot? 

The size of your plant is normally a reflection of the size of the pot it is growing in. Therefore, a 3-gallon pot will more than likely allow the plant to grow upwards of three feet. However, the process of growing cannabis, like other plants, can be a bit finicky. There are no absolutes. 

The size of the pot will also impact the yield of each plant. With larger pots, you may be able to grow larger plants, and therefore, yield more in the long run. 

To sum it all up: more root space, more yield. 

Will Cannabis Get Root Bound in a 3-gallon Pot?

Yes, there is potential that your plant will get root bound in a 3-gallon pot. With that being said, there is potential for any plant to get root bound in any size container, except for maybe the earth. 

Your plant getting root bound will depend on your grow timeline and the size of the container. In general, the longer the time frame, the more likely your plant is to become root bound. 

In the case of cannabis, it will depend on how long you intend to have your plants growing in their vegetative phase (aka “veg”) before the flowering phase. You will need to strike a balance between the germination, veg, and flowering stages of your plant’s life cycle in order to harvest your yield before the plants get root bound. 

How Long Should I Veg Cannabis in 3-gallon Pots?

Again, there is no black and white answer for how long your plant’s vegetative state should be. The answer to this question depends on the strain of plant you are growing and the elements of the environment it is growing in, such as light, temperature, and humidity. 

However, experts tend to recommend between 6-8 weeks of veg time.

It’s great to be prepared but defining the answer to this question will depend on a bit of experimentation and learning from the process (and hopefully not too many mistakes). 

How Long to Flower Cannabis in 3-gallon Pots?

If you are taking the recommendation, with a grain of salt, of course, to veg your plants for 6-8 weeks in a 3-gallon pot, then it is recommended to flower your plants for an additional 8-10 weeks. 

If all of this is beginning to sound like a really long time, and if you are becoming a bit nervous about issues from your plant becoming root bound, then you may consider transplanting your cannabis plant before the flowering stage.

What is Transplanting, and Should I Consider Doing It? 

Transplanting is the process of moving your cannabis plant from one place to another or from one container to another. Transplanting your cannabis will especially be important if you are growing indoors. 

To get your plants started, there is no need to grow them in a large container. Starting your plants in small containers, even plastic cups, will give them plenty of space to begin growing. 

The first transplant will likely occur sometime after germination in order to allow for growth in the vegetative phase. 

You want a larger container so that the roots of your plant can continue to grow happily. Remember, with more root space; your plant will become larger. After the veg phase, you may consider a second transplant for the flowering phase. This second transplant is much less crucial than the first. However, some folks prefer it.

For example, if you went to veg in a 3-gallon pot, you may consider transplanting to a 5-gallon pot (or larger) for the flowering stage. In a larger pot, you may decrease the chances of your plant getting root bound and increase your overall yield. 


Cannabis plants are incredibly resilient. They are able to grow in incredible ways and in the funkiest of places. A 3-gallon pot is absolutely one of the places. 

If you are able to create a safe environment with all the necessities your cannabis plants might need, then there is no reason why you cannot be successful in a 3-gallon pot. If you have the following items and a lot of patience, then you’ll be reaping the benefits in no time: 

  • Water 
  • Light (natural or from full-spectrum LEDs)
  • Ventilation (to control temp. and humidity)
  • Nutrients 

And patience. Don’t forget the patience. Good luck!

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