grrowing weed in garage tips

Best Grow Room Setup (Step by Step)

How To Build A Grow Room In A Garage Step By Step?

A garage can be perfect for a grow room. I will show you why in a moment… fact, I want to go as far as showing you how to build a grow room in a garage step by step and introduce you to some other popular grow room ideas

Let’s go right in:

You might be knowing this but even if, allow me to jog your memory a bit… A grow room is an interior space designed to be used for indoor gardening.

Now, a perfect indoor grow room is supposed to be completely sealed apart from the strategic ventilation. SHOP BEST SELLING GROW ROOM PRODUCTS

Origin of Grow Rooms

Marijuana Grow Room

The first people to come up with a grow room were marijuana growers. They were looking for a secure location to grow the herb away from law enforcers.

Let’s now come to size…

How Big Should A Grow Room Be?

Its size depends on the intended purpose. In some cases, it will just be a small area created from your spare bedroom or a converted garage.

It can also be gigantic. For example, a commercial grow room can be so large such that calling it a plant factory, or an indoor garden, or even an indoor farm won’t seem out of hand.

What’s The Difference Between A Grow Room and A Greenhouse?

Unlike a grow room, a greenhouse isn’t completely sealed so, they significantly differ. However, a grow tent is closer to a grow room – in fact, it is considered to be a mobile grow room.

Advantages Of Growing Plants In A Grow Room

Growing in your grow room will give you several benefits.

Here they are:

  • Control
It’s easier to manage light, temperature, and even humidity
  • Space economy
Grow rooms are one of the better choices for small-space gardening.
  • Protection
Growing plants are protected from nuisances such as bugs, dust, harsh weather conditions, or destruction by animals and humans
  • Better ROI
Plants are in a better overall condition and yield more. In the end, you will pocket more bucks. SHOP BEST SELLING GARDENING PRODUCTS

Things to Consider When Building A Growing Room

Before we finally see how to build a grow room in a garage step by step, let us look some of the factors to consider when setting up a growing room

For the best grow room setup, consider the following;

  • The materials you will use.
You shouldn’t use materials that can mold for your walls. You may have to change the garage walls if it’s currently made of moisture holding materials like wood .
  • Flooring
Water may drip from the growing trays or pots. To withstand water, your grow room’s floor should be at least cemented, tiled or vinyl floored.
  • Lighting
Lights are very crucial to indoor gardening; your garage grow room should be able to accommodate sufficient grow light fixtures even if it’s one of those small grow rooms that people start with.

A garage with windows allows natural light during daytime and in the process saves on electric usage.

  • Ventilation
Growing room should be very well-aerated. Good ventilation will also help eliminate any bad odor coming from the room. You will need to provide for an exhaust fan and a vent.
  • Electrical source
Your grow room also needs an electrical source. Luckily, any normal wall installed in your garage or nearby will do
  • Water supply
Needless to say, you will be watering your plants- even if occasionally. A nearby water source is therefore fundamental to your success. SHOP BEST SELLING GROW ROOM PRODUCTS

Setting Up a Grow Room Step By Step (In Your Garage)

With the considerations out of our way, let’s see how to build your own grow room…

Step 1 – Pick an Ideal Space

Decide on the size and the exact spot where you will site your upcoming grow room. You can convert the whole garage, partition a space for the grow room.

Pick a spot where it will be convenient for you to install all the key provisions like lighting, water point, and ventilation

Step 2 – Draw Your Floor Plan

Now, summon the designer in you. Map out all your ideas for the grow room of your dreams on paper.

Add dimensions plus placement of crucial elements such as intake vents and exhaust fans.

At this stage, you should also figure out the exact measurements- I am talking about the room’s square plus cubic feet.

This is important in as far as purchasing the right size of lights, vents. and fans later on.

Something else to decide here is where in the room will your plants go.

Certainly, this will be influenced by how you have chosen to place the lights and exhaust fan(s)

Step 3 – Insulating the Walls

It’s now time to handle the walls…

Set up the partition walls (if you chose to partition your garage).

Otherwise, now line your walls and the floor of your proposed room with mylar. This prevents moisture damage.

The mylar should be directly tacked on all the walls as flatly as possible.

Mylar also reflects the light around your entire room, thus fully utilizing your light source.

Step 4 – Install Lighting

You will need enough lights. Their number will be dependent on the size of the grow room. As a general guide, install one 600-watt light per every 5-6 feet of area.

Lights make heat, so if you have more lights, you will need a bigger extractor fan.

And if you will be using natural light during the day, you will need to additionally connect your lighting system to a relay & timer system. SHOP BEST SELLING GARDENING PRODUCTS

Step 5 – Install Exhaust Plus Intake Fans

Expelling hot air and drawing in some fresh air is very important.

Incoming air should be directed to the bottom area while the hottest air should be extracted from the top area since it is here that it flows naturally.

Generally, the output fan should be bigger than the input fan and you should set the system such that there will be an exchange of air around 30 times every hour.

Again, positioning your fan’s airflow towards the light bulbs will help to keep the temperature down.

In addition, use of HAF (Horizontal Airflow) fans help to maintain an even humidity and temperature throughout your grow room. This reduces condensation on the room walls meaning you will reduce incidences of disease on your plants.

Step 6 – Water System

With lights, plants dry out more quickly, so ensure you water as frequently as required.

Thus, connect your water system.

A hydroponics system can automate this bit so you may add it as part of your grow room setup.

Here is a fact:

Different crops have differing light, humidity, and even soil requirements. Therefore, Research the targeted plants to know their optimum conditions to ensure your grow room will be productive.

Step 7 – Extra Tools

Fit any other tools you may need like humidity meter, pH meter, thermometer, etc.

Although not crucial, they help you to diagnose your plants as soon as you detect problems.

Step 8 – Set Up The Containers

Set up your grow room containers. You can go for hydroponics or soil depending on your budget

Step 9 – Planting

Now, plant your germinated seeds, or whatever else you were to plant in the grow room. SHOP BEST SELLING GROW ROOM PRODUCTS

Build A Grow Room Cheap

If you are on a budget, you can tweak a few things and still end up with a superb grow room.

Let’s skim through them;

  • For growing medium, use soil rather than hydroponics. It’s by far much cheaper and also has less work.
  • For lighting, go for CFLs (compact fluorescent light) are cheaper yet as efficient as other alternatives, LEDs included
  • Instead of Mylar for reflection, use flat white paint. It’s a budget option yet it still reflects more light ( up to 85%). Plus, surfaces painted flat white are easier to keep clean.
So, that’s how to build a grow room in a garage step by step. We have also seen other grow room ideas that can make the whole process cheaper and the most important considerations.

It’s now your turn…

Share with us about your perfect indoor grow room from the comments button below.


A garage can be perfect for a grow room. I will show you why in a moment… fact, I want to go as far as showing you how to build a grow room in a garage step by step and introduce you to some other popular grow room ideas

1st Grow in My Garage – Auto Northern Lights in Grow Box Under 400W HPS – 5.35 oz Harvest

by [Name redacted per request]

Quick Grow Snapshot

  • Strains: 3 x Auto-flowering Northern Lights
  • Grow medium: FF Soil
  • Grow Light:
    • Vegetative: 6400k T5 Grow Light
    • Flowering: 400W HPS with digital ballast and air-cooled hood
  • Nutrients or Additives: Fox Farms Soil Nutrient Trio

May 5, 2012: Seeds sprouted
July 29, 2012: Harvest!

Total Time – Seed to Harvest:
85 days (2 months, 24 days)

Final Yield
5.35 oz

View full grow journal below!

Getting Started – Pre-Grow

With space to grow in the garage, I decided to build a grow box and try my hand at growing marijuana, even though I’d never grown anything before.

In addition to learning grow skills, building my box was a big test of my carpentry skills, or lack of skills I guess I should say. I’d never built anything like this before.

Planning My Grow Box

Build grow box out of plywood and 2x2s with 2 chambers so I can swap the plants between the chambers when it’s time to flower.

The dimensions of the box are 4’W x 2.5’D x 5’H.

The grow box cost me about $135 for the lumber, screws, caulk, sandpaper, wood stain, and hinges.

You’ll see how the box is divided into 3 sections. I want to put a vent in the ceiling of the bottom right section and a vent in the top of the wall in the left section so that both of them feed into that top part where my carbon filter will be.

What would be the best way of ducting both of those vents into a single carbon filter?

Choosing The Right Grow Light

I was concerned about heat and light usage for my small space.

I looked at LEDs when I first started my research, but I kept reading things about them being kinda sketchy. A lot of people seemed to think they didn’t live up to all the hype.

I considered using T5 grow lights for both the vegetative and flowering stage (6400k bulbs for vegging and 2700k for flowering) because they produce such low heat.

I was hesitant about using a T5 in flowering, though. Some growers seemed to be getting good results with them, yet I was worried that a T5 was not going to be intense enough to get good yields in the flowering stage.

I decided to go with a 400W HPS light with an air-cooled hood and exhaust fan for the flower chamber. It was hard to resist getting a bigger light, but I knew that a 600W was going to be too big/hot for my space.

Final Setup

  • Vegetative: 6400k T5 Grow Light
  • Flowering: 400W HPS with digital ballast and air-cooled hood

  • Fox Farms Ocean Forest Soil

  • Fox Farms Soil Trio

  • Feminized Northern Lights (from Pyramid Seeds), ordered them from Attitude I probably wouldn’t order seeds from this breeder again. The seeds ended up being an autoflowering strain even though it was advertised as being a photoperiod strain. It all ended up working out, but I would have been happier if I’d received the seeds I ordered.

My First Grow In Pictures!

I started germinating my seeds in a shot glass.

I put the seeds in a shot glass filled with water to germinate them I put the seeds in a shot glass filled with water to germinate them

Seeds have sprouted roots

I’ve got a pack of these pellets to start them in. I did a test run by putting a pellet in a cup of water, damn those things expand!

Here is what I ended up doing, I tried to cut out any extra steps and just put the pellets directly into the soil from the start.

I put bottles on top to help retain extra humidity (like a humidity dome). Here are my ultra cheap humidity domes

Seedlings under T5 Grow Light in Veg Chamber. It’s a steady 85 degrees F in there, no idea about the humidity in the bottles.

Day 7 from seed

Day 13 from seed

Day 19 from seed – Plants started looking a little sick

Leaves started looking sick on Day 19 I thought they may have used up all the nutrient in the soil (I haven’t been feeding extra nutrients until now). I started feeding them with Fox Farms Nutrient Trio.

I also considered it might be stress from the wind of the fan, so I got a lot more careful about blowing air on the seedlings.

With these two changes, the problem seemed to sort itself out.

Day 39 from seed – Moved plants into flowering chamber under 400W HPS

I moved the plants into the flowering chamber with the 400W HPS grow light.

At this point, I continued to keep them on a 18/6 light schedule, which should have kept them in the vegetative stage. I wanted to let the plants get a bit bigger before switching them to flowering.

I did not yet realize that these were autoflowering plants.

Day 41 from seed

Today is also the first day I’ve tried to LST (low stress training). I know it’s generally recommended to start LST earlier, but I was trying to avoid it on my first grow just to see how my yield would be with no training.

I ended up LSTing one of the girls who was getting too tall.

I was surprised to see my plants start flowering (you can see a couple of flowers starting to appear in the picture above).

I’d purchased non-autoflowering seeds. Guess I’ll never order from that seed vendor again. At first I thought I was seeing pre-flowers, but I soon realized my plant was producing full-on flowers.

Then I saw something even more scary, a hermie banana…

On the advice of others, I plucked this single banana and finished flowering my girls. This was the only hermie sac I saw throughout the grow, and I’m glad I ended up finishing the girls because I had a fantastic harvest.

Day 45 from seed – Closeup of trichomes on the buds and surrounding sugar leaves

Day 53 / 54 from seed – Buds are fattening up

The plants in the grow box definitely smell at this point, but it only became noticeable to me within the last few weeks. Even now it’s not too bad, and you would have to be in the same room as them to smell it.

Day 63 from seed

Closeup of trichomes

Day 79 – End… The final days

At this point I still don’t have a fan hooked up to my vented hood and I’ve been relying on a wimpy little one and keep the door cracked open to let the heat out.

For my next grow I’ll have a real ventilation system set up and heat shouldn’t be a problem. I’ve been running my light at half power (200W) for the past couple weeks to control the heat. I’ll have much better ventilation my next grow so I’ll be able to run it at 400W the whole time.

Day 84 from seed – Day before harvest (ready to be cut down)

I’m really happy with how they turned out.

For my 2nd grow I’ll have 4 plants instead of 3 and I’ll be LSTing from the start.

Also, I will finish my grow box by hooking up a fan to my hood (with a carbon filter), and I put mylar up on 2 of the remaining walls where I still need to cut some holes.

My light has only been running at 200W for a majority of the grow because the weather has been so hot and my ventilation sucks.

I’ll be really interested to see how much doubling the light, making all the other minor improvements, and avoiding all my previous mistakes will affect my yield.

Day 85 – Harvest!

I ended up having to go to a pet store and buying some activated carbon to control the smell of my drying buds. I knew it would smell, I just didn’t think that much!

Harvest Final Weight 5.35 oz!

My 2nd Grow in Pictures!

Stay tuned for my second grow in pictures.

Here’s a quick preview…

Are You Ready To Start Growing, Too?

So you’re ready to start your own indoor grow…

You know the space you want to grow in, but you have a few questions…

There’s so many confusing options out there, yet you no longer have to figure it out all on your own.

This quick article will guide you through the whole process.

Get the right equipment for YOUR grow space

1st Grow in My Garage – Auto Northern Lights in Grow Box Under 400W HPS – 5.35 oz Harvest by [Name redacted per request] Quick Grow Snapshot Strains: 3 x Auto-flowering Northern ]]>