How Many Cannabis Plants Should I Grow? (For the Biggest/Fastest Yields)

Updated Nov 15, 2020

by Nebula Haze

Should you grow just one cannabis plant or many to maximize your yields? What’s the best number of plants to grow considering your grow light and the size of your grow space?

What’s the best number of plants to grow?

What's the best number of cannabis plants to grow to get the best yields in your setup?

There are a few different schools of thought when it comes to the best number of marijuana plants to grow in an indoor setup. I’ll walk you through the benefits of growing just one plant vs the benefits of growing many, and then give you some real-life examples with specific setups. That way you get the information you need to make the best decision for your garden

One or Many Cannabis Plants: Costs vs Benefits

Growing Just 1-2 Cannabis Plants at a Time

Pros

  • Easier – Fewer plants make it easy to pay attention to each individual plant and it’s often easier to reach all the plants.
  • Much Simpler – You won’t need to compromise as much between plants with different needs.
  • Less Time Daily – Spend less time on a daily basis caring for plants (making nutrient water, watering, training plants, etc).
  • May Be Only Legal Choice – Many growers live in an area with a limit on the number of plants they can grow (for example in Canada you are only allowed to grow 4 plants at a time, and each legal US state has different growing rules). These growers don’t have a lot of choices when it comes to how many plants to grow.

Cons

  • Less Variety – You’ll only be able to grow one or two strains, instead of many strains at once.
  • Fewer (or Smaller) Harvests – Yield is based on how well you fill the grow space with plants before they start flowering. With just one or two plants, it takes extra time for each plant to fully spread out in the vegetative stage so you achieve the best yields. This results in fewer harvests a year. Alternatively, if the grow space has empty spots during the flowering stage you’ll end up with smaller yields.

Should you grow just one or two plants at a time and let them get big?

This marijuana plant was trained to grow short and flat - this allows one plant to yield as much bud as many smaller cannabis plants

It took 8 weeks in the vegetative stage to train the plant to grow this way. Yet it was a joy to focus on just one plant and get to form a relationship with it.

View of that same cannabis plant from above

In the flowering stage, the plant rewarded the effort with buds that filled the space where the plant was trained

Example of a single plant that was manifolded and trained so it would produce as much as many smaller plants

Growing Many Cannabis Plants at a Time

Pros

  • Faster Harvests – Especially in a large grow space, several plants can fill the space faster during the vegetative stage than just one or two plants. This allows the grower to switch to the flowering stage sooner.
  • Max Yield for the Time and Electricity – A shorter grow period results in extra harvests. If you are looking to get the biggest yield in the shortest amount of time (maximizing your yield for the electricity), this is an effective strategy.
  • More Variety – With a higher number of plants, you’ll have the ability to grow a greater variety of strains at the same time.

Cons

  • More Daily Care – You will usually spend more time on a daily basis tending your plants, and it’s often more difficult to reach the plants in the back.
  • Different Plants Have Different Needs – Each plant prefers slightly different levels of nutrients, light intensity, etc. The differences can be especially stark when growing many different strains at once.
  • More Difficult to Train – Training plants to grow wide and flat results in the best yields, but it can be more difficult to train multiple plants. Some plants grow much taller/faster than others, and you have work around all the other plants. To simplify things, some growers avoid any training when growing many plants at once.
  • May Be Illegal Where You Live – It may be against the law to grow a large number of plants even if growing is legal where you live.

Should you grow many plants so they fill your grow space faster?

Start out with many small cannabis plants growing in pots

It only took 6 weeks for those plants to completely fill up this grow space. Imagine how long it would have taken for one plant to grow this big!

Example of growing many small cannabis plants instead of just a few bigger ones (known as the "Sea of Green" training method)

No Matter How Many Plants You Grow…

  • Similar Yields Per Square Foot – Cannabis yields are based mostly on the size/shape of the canopy in relation to your grow light, not the number of plants. Filling the total surface area of plants under the light with bud sites is what matters, and it doesn’t really matter if you use one plant or many to fill the space before flipping to the flowering stage.

That means even if you can only grow a few plants at a time, you can still get the same yields in your grow space as someone who can grow more plants! It just might take a little bit longer in the vegetative stage.

It doesn’t matter whether this canopy was created by one plant or many. However you got here, your yields will be about the same as long as everything else is equal!

Example of a sea of cannabis colas - it doesn't matter this is made up of one plant or many, the results and yields will be about the same!

Growing Many Plants Shortens the Vegetative Stage But Doesn’t Necessarily Increase Yields

When it comes to getting the best yields as fast as possible, you will often have better luck growing several plants than just one or two. This is because it takes several plants less time to completely fill up a space than it would take one plant to fill up that same space.

However, time might not be the main concern. Many growers don’t mind an extra few weeks in the vegetative stage if it makes the growing process easier and more fun.

But in the end, the actual yields will be about the same as long as the space does get filled. Given the same total number of colas and size of plants, it won’t matter much if you have one plant or twenty as far as yields are concerned.

Many small plants will let you fill a space faster in the vegetative stage

What’s the “Optimal” Number of Cannabis Plants?

If you can legally grow as many marijuana plants as you want and are willing to put in the extra time and effort to grow as many plants as necessary, what’s the best number of plants to grow?

Each plant should get plenty of direct light and at least a foot or two of space to itself

Example of many cannabis plants filling a grow space

The optimum number of plants depends mostly the size of the area under the grow light. A plant generally should get at least a foot of space to itself to really be able to grow and spread out, and it’s often better to give plants a little more space, especially if you have powerful grow lights like HPS or LEDs!

Suggestions for Example Grow Spaces

2’x2′ Space – 1-4 Plants

2’x4′ Space – 1-6 Plants

3’x3′ Space – 1-6 Plants

4’x4′ Space – 2-9 Plants

These suggestions definitely aren’t set in stone, but they serve to give you general starting guidelines. It is possible to grow more plants in these spaces successfully, but with more plants, you will often start running into difficulty being able to reach the plants in the back and care for them properly. Sometimes it’s more of a pain than it’s worth.

These two plants fill this entire 4’x4′ space, but you could get the same amount of canopy coverage with many smaller plants. It’s up to you to decide how you want to fill your space

Example of 2 cannabis plants in a 4'x4' tent under a grow light

Keep in Mind! Your yields are limited by the size of your grow light, not the number of plants. Light is like food for your plants and has a direct correlation with yields. The more plants you grow, the less each individual plant will get as far as light. Think of your grow light like a pie, with each additional plant getting a smaller slice to eat every day.

It’s tempting to grow a lot of plants, but you don’t want to spread your light out too thin! If you grow too many plants you might get less than an ounce per plant, and your buds will be airy and light!

Your yields are ultimately limited by the size of your grow light, regardless of how many plants you grow.

Cannabis colas under an HPS grow light

All of the following grows took place in a 2’x4’x6′  tent and produced a comparable amount of weed

3 plants (5-gallon pots)

4 plants (3-gallon pots)

7 plants (2-gallon pots)

It can be hard deciding what number of plants to grow in your space, but ultimately the best thing you can do is to pick a number and dive right in to growing. I believe in listening to your gut. When in doubt, always start with more plants than you need so you have the option of ditching any plant that doesn’t germinate, grows poorly, or ends up being a male or hermie.

Always start with more plants than you need, just in case! But remember, you may have to throw some of them away… 

Each grower has a different style, and as you get more experience, you’ll be able to dial in your grow to what’s best for you and your setup.

Many growers find it more relaxing and enjoyable to grow just a few plants (or even just one). On the other hand, growing many plants at a time produces more strains, more often. The right choice depends on you and your needs.

So unfortunately I can’t give you a “best” number to end all numbers, but I hope you now have a better idea of how many plants to grow in your space!

 


 

Jump to…

Simplest Grow Guide Ever!

Beginner Shopping List (What You Need to Start Growing)

How to Increase Your Yields

Diagnose Your Sick Plant!

 


 

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