Growing Cannabis Indoors vs Greenhouse: Which is Right for You?

Imagine this: you’ve been growing cannabis for a while and you’ve gotten pretty good at understanding of the process. You want to take your cannabis operation to the next level but you’ve come to a crossroads — an indoor grow room or a greenhouse. 

Both these methods of cultivation are the next step up from outdoor gardens, and most serious growers have to decide between the two methods. Which is better? The answer isn’t as simple as it looks. 

So, let’s dive into the differences between indoor and greenhouse cannabis and see which one will suit you best. Here’s everything you need to know about indoor gardens and greenhouses. 

What is Meant by Growing Cannabis Indoors?

Indoor cultivation of cannabis is a different concept from greenhouse or outdoor methods as it takes several more steps than the other two. The goal of an indoor garden is to simulate an outdoor environment without the risks that come with it, including the risks that come with greenhouses. 

But don’t think that indoor cultivation is a niche segment; it may be relatively uncommon for hobby growers but a Cannabis Business Times report states that 60% of the cannabis is grown in an indoor environment — this is largely practiced by commercial growers where the overhead costs are tremendous and risks are something they cannot afford. 

A traditional indoor setup involves many things to create an artificial environment for the plant to thrive. Ideally, you need to invest in grow lights — HPS was the most popular but LEDs are gaining traction — such lights mimic the natural sunlight, or at least try to.

Once the light is sorted, you need to move to the air — you need a proper ventilation system, which gets more complex the bigger your garden gets. Then you need climate control in the form of HVAC, air conditioners, air purifiers, dehumidifiers/humidifiers, carbon scrubbers, etc. 

Apart from that, you need to figure out the cultivation method in the form of soil or hydroponics. For indoor growth, a majority of growers choose hydroponics since it offers various benefits over soil-based plants, but some growers still stick to the traditional virtues of soil-grown cannabis.

When you figure these things out, you have ultimate control over your indoor cannabis plant. You control the lighting, humidity, temperature, irrigation, and almost every other aspect of the plant’s growth. 

Thanks to this level of control, you can not only grow cannabis year-round but also grow it to your standards. Plus, an indoor environment keeps your cannabis safe from natural risk factors like pests, unpredictable weather, lack of sunlight, light leaks, and even peeping neighbors. 

Advantages of Growing Cannabis Indoors

We already glanced over a few benefits of growing cannabis indoors above, but let’s delve deeper into the various benefits that come with growing cannabis indoors. Here are the benefits you get with indoor cannabis cultivation.

1. Control of Your Plant’s Growth 

The biggest benefit of growing cannabis in an indoor grow room is control, and no other cultivation method can match this. With an indoor cannabis grow room, you mimic the outdoor environment but you retain all the control over it, so you don’t have to rely on the weather outdoors. 

Here, you get to decide how your cannabis plant grows — its flowering time, size, height, the type of light it gets, the temperature and humidity levels, nutrient levels, irrigation, etc.

2. Lack of Environmental Risks 

A good indoor grow room includes vents that are fitted with filters, which prevents various environmental risk factors from making their way into your garden, such as pests, mold and fungi spores, and pathogens. 

Of course, some indoor cannabis grow rooms may still get these problems once in a while, but the chances are far lower compared to an outdoor or even a greenhouse setup. This usually happens due to grower error. 

3. Grow Cannabis Year Round 

If you are a hobby grower, you wouldn’t mind growing cannabis according to the season, but you can’t afford this if you are a commercial grower. In that case, you can grow cannabis indoors and ensure you can grow your plant year-round even if you live in Siberia. 

This is because no matter what the environment is outside, your indoor grow room has its own artificial microenvironment that is not affected by the weather. Yes, this does come with its costs and efforts, but it’s worth it for commercial growers. 

4. Predictable Yield 

Because you control how your cannabis plant grows, you can more or less predict the kind of yield you’ll get. Of course, you still need to know the basics of your particular strain’s genetics, but it gets a lot easier with an indoor plant. The variables are minimized to a great extent. 

5. Discreet 

The last benefit of indoor cultivation is that it is a discreet way of growing cannabis. Many growers prefer this mode to prevent judgment, legal trouble, or vandalism. While cannabis may be legalized now, there’s still a stigma around it in many regions. 

Disadvantages of Growing Cannabis Indoors

Growing cannabis indoors sounds incredible, doesn’t it? But wait till you hear about the disadvantages that come with it — there are a few major ones, such as the following. 

1. High Operation Costs

One of the things that turns many growers away from growing cannabis indoors is the high operating costs. It’s a major limitation. The thing is, setting up an indoor environment can get fairly expensive quickly, especially if you choose to use high-quality parts and LED lights. 

The setup itself may cost anywhere from a couple of hundred dollars to thousands — a small space bucket setup is cheap but it can only grow a single plant. If you want to grow multiple plants in the best possible manner, prepare to spend over ten thousand dollars on the setup.

That’s not where it ends, though. Indoor grow rooms require maintenance, especially certain hydroponic setups. Plus, it’s a very energy-intensive method, so you’ll be spending a lot of money on energy bills, too. 

2. Space 

Another drawback of an indoor setup is the availability of space. Sure, you can grow cannabis in a computer tower, but if you are serious about your cannabis, you’ll need a dedicated grow room, which may not always be possible, especially if you live in a city. 

3. Quick Contamination 

Indoor cannabis grow rooms are relatively safe from pathogens and pests, but some can still find their way in occasionally. And if this happens and you fail to pick up the signs on time, it won’t be long before the contamination has spread to other plants. 

It’s a closed environment with plants placed in close proximity, sharing the same air, so contaminants like pests and spores can travel fairly fast to other plants. 

What is a Greenhouse? 

Think of a greenhouse as a middle ground between outdoor and indoor cultivation methods. This is a very common method of growing cannabis in the States; according to Cannabis Business Times, 41% of growers in the US use greenhouses for growing cannabis. 

You may have learned a bit about this in your school, but to brush up on the memory — a greenhouse is a garden that’s covered with transparent glass or plastic structure. This system allows the plant to enjoy natural sunlight while thriving in a relatively controlled environment. 

Of course, you can always add more light or deprive the plants of light in a greenhouse setup to suit your photoperiod cannabis growth pattern, but what greenhouses primarily give you is more control over the temperature and humidity of the garden. You can also manipulate other factors, especially carbon dioxide concentration within. 

If you want to grow cannabis in a greenhouse and have the space for it, you’ll get better results. Greenhouses also protect the plants from pathogens like pests and fungi to a great extent, reducing your need for using pesticides in the garden. This, while allowing your plants to get the benefit of an outdoor environment as much as possible. 

Advantages of Growing Cannabis in a Greenhouse

Greenhouses are popular in farming for the tremendous benefits they offer. Some of the best benefits of growing cannabis in a greenhouse are as follows:

1. Extended Growing Season 

Like an indoor setup, a greenhouse also allows you to extend the growing season of your cannabis plant. You will need to invest in some supplemental HVAC systems and lighting to make this happen, but it can be a great workaround if you prefer outdoor cultivation but have a slightly shorter growing season in the region. 

2. Energy Efficiency 

One area where greenhouses have an upper hand over indoor grow rooms is energy efficiency. Lighting systems, even LED grow lights, consume a lot of energy and are the primary reasons for high energy bills in an indoor grow room. 

A greenhouse eliminates the need for grow lights while still retaining some of the other benefits of an indoor grow room. The result is that you no longer have to spend exorbitant amounts of money on energy bills. The sun takes care of your cannabis plant’s lighting requirements. 

3. More Control 

Greenhouses cannot match an indoor grow room when it comes to control, but they can still work for a certain set of growers. Greenhouses allow you to control the temperature and humidity around your plant, and to some extent, the light. This can be a terrific benefit if you want to make slight adjustments to the environment without retaining complete control. 

Disadvantages of Growing Cannabis in a Greenhouse

Greenhouses have as many drawbacks as they have benefits, and here are some of the major drawbacks of growing cannabis in a greenhouse. 

1. Not So Safe From the Environment 

Greenhouses, by design, separate your cannabis plants from the outdoor environment but they aren’t 100% safe. They can be sealed, can be partially open, and most greenhouses still use soil as a growing medium. 

As a result, a greenhouse is at a bigger risk of outside elements, like temperature fluctuations, inconsistent sunlight, weather, pests, and pathogens. Some of these factors can be solved, but greenhouses are less safe than an indoor setup by default. 

2. Higher Upfront Costs 

Greenhouses may be cheap to maintain over the course of your plant’s cultivation (read: no growing lights), but you may still have to spend a lot of money on setting it up. If you are a home grower, you can make a polytunnel with household items and basic plastic sheets, but anything more advanced and you’ll need a dedicated greenhouse, which can cost a lot of money depending on its size and features. 

Indoor Grow Room vs Greenhouses: Which is Better?

Now that you have a general understanding of both indoor grow rooms and greenhouses, let’s compare the two cannabis cultivation methods side by side and see how they fare against each other. 

1. Light Quality 

One of the most important aspects of growing cannabis is light, and this is also the biggest difference between an indoor grow room and a greenhouse. Indoor grow rooms utilize artificial light from grow lights that mimic natural sunlight. On the other hand, a greenhouse primarily relies on natural sunlight. 

That doesn’t mean an indoor grow room will produce subpar results — it can still produce excellent results since you have so much control over the light — but it is usually an expensive solution. On the contrary, a greenhouse produces good results thanks to sunlight, but the light isn’t always consistent, especially if the weather is cloudy. 

You can even find indoor grow lights that produce the right kind of PAR for cannabis plants, which is the spectrum of light that plants use to produce energy, and it’s not the same as visible light. 

However, indoor grow lights have one drawback when it comes to light — they produce UV-A light but plants require UV-B light. The former does help the plant produce more terpenes and secondary metabolites, but UV-B light is always better for plant growth, which is found in natural sunlight. 

The difference? A cannabis plant grown in a greenhouse will tend to produce tastier buds than indoor plants, but an indoor grow room’s light will always be consistent and controlled. 

Winner: It’s a Tie

2. Level of Control 

Unlike outdoor cultivation, indoor grow rooms and greenhouses offer you a lot of control over your plant’s growth, but the levels at which they offer this vary a lot. As mentioned earlier, an indoor grow room offers the best control over your plant’s growth in terms of the type of light, temperature and humidity, air circulation, CO2 levels, etc. 

On the other hand, a greenhouse sits somewhere between an indoor grow room and an outdoor garden, depending on the type and scale of your greenhouse. Here, you can either have a basic greenhouse that uses most of the natural resources while keeping your plants covered or a sealed greenhouse that uses natural sunlight but everything else is artificially simulated. 

So, which system will produce better plants in this context? It entirely depends on the level of control you want to achieve. Both can produce excellent yields, depending on your cultivation strategies. 

Winner: Again, It’s a Tie

3. Costs

This is where the differences start showing up significantly. Both greenhouse and indoor grow rooms are expensive upfront, but an indoor setup will usually cost you more, considering you need a dedicated space with expensive grow lights and climate control systems.

On the other hand, a greenhouse uses whatever is available and supplements the rest with add-on features like climate control or supplemental light. Plus, you can save a lot of money by DIY-ing a greenhouse for growing cannabis. 

However, the differences start showing up once you start growing cannabis. An indoor grow room will be more expensive to maintain and run since the grow lights and other peripherals will use a lot of energy. 

A greenhouse is much cheaper comparatively since you’ll be using natural sunlight and, sometimes, even the ambient weather. But sometimes, you may have to spend a bit of money on maintaining the greenhouse structure, which can get damaged by the weather, especially strong winds. 

Winner: Greenhouses 

4. Quality of Yield 

Coming to the quality, you can measure the distinctions between cannabis plants grown in a greenhouse or an indoor grow room. 

A cannabis plant grown indoors will produce more consistent results throughout, even after multiple cycles of harvest. As a result, you can predict the kind of yield you will have and not have to worry much about deviations in the quality or quantity of the yield. 

On the other hand, a greenhouse cannabis plant may not offer such consistent results. Of course, both the yields will be close to each other in terms of quality and potency, depending on the strains used, but expect a bit of deviation that may come from the changing sunlight supply. 

This is the reason indoor cannabis buds sell for a much higher rate than outdoor or greenhouse cannabis buds — consistent quality is almost always guaranteed. 

Winner: Indoor Grow Rooms 

5. The potency of the Yield 

Potency is something that must be addressed individually, too, and this is where indoor grow rooms shine as well. A controlled environment will always produce more potent buds, i.e., the THC and CBD levels in the plant. 

In an indoor grow room, you simply have more control over the plant you grow and you can always manipulate the environment to boost its potency. The same level of control is missing in a greenhouse, so you can’t push the plant to its full potency unless it gets the exact conditions needed for best growth.

In general, both indoor and greenhouse cannabis plants produce more potent buds than outdoor-grown cannabis, but indoor grow rooms still have a slight upper hand. 

Winner: Indoor Grow Rooms 

6. Energy Efficiency 

Did you know that Colorado’s cannabis industry sucks 2% of the state’s electricity? That’s largely down to extensive grow rooms using comprehensive lighting and climate control systems, which suck energy as if they got it as a Christmas present. 

So, if you want your cannabis plant to be more energy efficient — whether for the environment or your wallet — you should stick to greenhouse cannabis cultivation. A greenhouse uses fewer electrical components, so while you may still spend a good amount of money on energy, it will still be significantly less than what you would spend on an indoor setup. 

In fact, you can further cut down the energy costs of greenhouses by using various methods like energy retention curtains, waste heat supplementation, water evaporation, etc. to warm or cool your cannabis greenhouse. 

Winner: Greenhouses 

7. Safety and Discreet-ness 

Safety is a major concern for cannabis plants, not just from the environment and pests but also from people. In this case, an indoor grow room is the safest option, and with some nifty devices, you can completely conceal your cannabis operation from your neighbors — they’ll never know the best weed in town is grown next door. 

On the other hand, a greenhouse is relatively safe from the weather, pests, and pathogens, but not from the public. Greenhouses stick out like a sore thumb, especially in urban environments, so expect a lot of attention unless there are many greenhouses in the vicinity already. 

Winner: Indoor Grow Rooms 

Summary: Growing Cannabis Indoor vs Greenhouse: Which is Right for You?

On the surface, it may seem like indoor grow rooms are better than greenhouses — the benefits of the former far outweigh the latter — but the correct answer for you may not be so simple. 

Greenhouses are usually the first step to take when you want to move away from an outdoor setup, followed by an indoor grow room. So, for most growers who are relatively new and want to expand their scope of operation, the greenhouse is the ideal choice. It’s cheaper to run, easier to maintain, and a tried-and-tested method of cultivation. 

On the other hand, for serious growers who want utmost control and don’t mind splurging, especially commercial growers, an indoor setup is a no-brainer. It’s the better choice of the two. 

But again, you must consider various other factors when choosing between the two apart from mere skills or expertise. Do you need supplemental light or is the natural light enough? Does social stigma pose a threat to your plants? Do you need to worry a lot about unpredictable weather? 

Questions like these will help you figure out which cultivation method is right for you.