Garages can provide an excellent inside place to grow cannabis. First of all, there are many design options when building a grow room in a garage. Growers can treat the open area as a large grow room with multiple lights or section off a corner to grow just a few plants. You have options. Some garage grow rooms are in plain sight, and others are concealed behind false walls. Personally, nothing is cooler than a secret door.
Want to explore your options? In the following sections, we will cover the crucial details for gardeners to consider before growing cannabis in the garage.
Planning your garage grow room
What you build depends on your needs. Growers that may need to deconstruct the garden area quickly, in the case of a landlord visitation, should opt for grow tents. These can be removed and set up in less than an hour.
Have a lot of space? If only the back section of the garage is used for growing, build a false wall to conceal the garden space. However, if the plan for a garage grow room is to have multiple small cells, it’s fairly hard to hide what you are doing if someone enters the garage. The best garage grow room plan will be custom to your situation, but there are a few constants to address.
Power: Where are the outlets? Are they all on the same circuit breaker?
Insulation: Are the walls and ceiling insulated?
Venting: Where and how will you exhaust grow room air?
Grow space style: Will it be an open room, a custom build, or will grow tents be used?
Plumbing: Is there a source of water to fill watering cans or to replenish hydroponic setups? Or will it need to be carried from inside?
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The pros and cons of growing cannabis in your garage
Advantages of growing marijuana in your garage
Building a grow room in a garage can take advantage of unused space under the roof. Most garages have concrete floors, which allows for easy cleanup of soil or liquid spills. Growing cannabis in the garage is also great for parents because it removes the grow area from the children’s area. Most garage doors can also be locked, which is a secondary method for keeping children and pets out.
Keeping an indoor marijuana grow out of the main living area makes inviting guests or family to visit less nerve-wracking. The chances of having your grow room setup discovered by someone opening the wrong door are far less when growing cannabis in the garage. When growing indoors, odor is a concern. Despite using carbon air filters, there will always be a slight plant smell in the immediate area.
Other Advantages:
You can increase yields in a garage, thanks to a larger growing area for growing larger (longer vegetation) or more plants.
Because of the additional headroom in garage grow rooms, HID grow lights can be a viable lighting option. The industry preference, though, is LED lighting, which is more efficient and cost-effective.
How you build a grow room in a garage is entirely up to you, but if carpentry isn’t your forte, using marijuana grow tents is the way to go.
Disadvantages of growing marijuana in your garage
Garage grow rooms are seldom perfect from the start. Garages tend to be the coldest or the hottest place in the house, depending upon the season. That means walls will need to be insulated to maintain temperatures. You’ll likely need equipment like humidifiers, dehumidifiers, and air conditioners for greater temperature control in the garage and to help maintain proper environmental conditions.
Concrete floors can also transmit cold temperatures to the root zone in winter months, harming growth. Some garage grow room plans utilize pallets to negate this issue.
Indoor gardeners go out of their way to conceal smells from the grow room because they worry about nosy neighbors and being reported to the law. One thing that will get a garage grow noticed faster than the smell is light pouring out of the cracks in the sides of the garage door at night. You can seal your garage, but sealing a garage grow room can be tricky. Seal cracks and corners with spray foam or HVAC tape or cover them with blackout curtains, but remember, it is hard to make everything airtight. If the garage has windows, those must be carefully covered, too.
Other disadvantages:
The potential for pest infestation increases when growing in a garage. This is especially true if a garden or other vegetation is immediately outside the garage door. If you store lawnmowers or other garden equipment in the garage, bugs can also hitch a ride on them.
Cleanliness will be an important part of your garage grow room plans.
Garages also often have poor air circulation, which can increase the potential for mold and mildew. Growers should be conscious of areas of stale air (particularly in corners) and rectify them using fans to increase air movement.
Tips for designing and building a grow room in your garage
Some garage grow room plans call for building walls instead of tents. Both are good options, but they have different considerations. The tips below address growers who intend to build a grow room in the garage. Remember, unlike tents, walls can’t be slid over a few feet whenever you feel like it.
Placement
Garages are where people commonly find things like water heaters, furnaces, boilers, and heating duct / HVAC systems. These items can be sources of additional heat (micro-climate), propane, and carbon monoxide gas, which can reportedly impact plant health. It is best to build your garden space away from these essential units.
As many of us aren’t certified repair folk if the hot water tank breaks and we need to call a service person out to fix it, having clear access to the tank without walking through the plant area is a plus. If the pilot light on the furnace goes out, a repair person must come out to light it. When building a grow room in a garage, place it away from essential items that may need service.
Materials
The wall boards you choose can impact your potential for mold and mildew. Choose a material that is not overly absorbent. This is important considering the often humid conditions within the grow area. Instead of general-purpose drywall, look for “green board.” It is similar to drywall but is water-resistant. Green board has a thicker paper coating, protected by a wax layer over the gypsum core.
The walls of a grow tent are reflective to direct the light energy back toward the plants, but ordinary walls aren’t nearly as effective. Paint bare walls white to increase reflectivity. There are a variety of paint brands that offer a white-colored primer with special anti-fungal properties. Take the added step against this pathogen and buy paint with these properties. In the US, KILZ and Zinsser are popular brands with added mildew and mold blockers.
Lastly, if you install a door to each grow chamber in your custom garage grow room, ensure they swing out, not inward. If the door swings into the chamber, you won’t be able to have cannabis plants in that area, which reduces the efficiency of the dedicated space. Make sure your doors open out (pulls towards you).
Electrical
Always have a licensed professional perform any electrical work. Garages are typically where you find the circuit breaker boxes, which makes a new outlet or breaker cheaper to have installed. It is possible for new outlets to be tied into an empty breaker slot or to have a new one installed to carry the electrical load from all of the grow gear.
You don’t need to tell the electrician that the higher Amp breaker or new outlets are for grow equipment. Many people use their garage as a hobby area. The addition could be for heavy-duty woodworking equipment or a kiln to fire your clay pottery. Whatever your story, make sure you know a little bit about the subject, like a model number, in case the hobby is also an interest of the electrician. Growing cannabis in the garage should be kept private; don’t offer that information to anyone.
How to control the climate and ventilation of your garage grow room
Controlling the climate is the largest challenge of building a grow room in a garage. Start by insulating the walls. Whether that means proper insulation or 4ft x 8ft (1.2m x 2.4m) foam insulation boards, this will greatly reduce temperature fluctuations.
You’ll need machinery to keep the ideal temperature and humidity levels in a garage grow room. Common machinery includes
Humidifier
Dehumidifier
Air conditioning
Heater(s)
You can ventilate your garage grow room in a few ways. Suppose you do not have close neighbors or are unconcerned with the odor post-carbon filter. In that case, you can install what looks like an extra dryer vent on the outside wall and connect the exhaust to that. However, for discreetness, there is something better.
The best way to vent your garage grow room is to run the exhaust into the attic and out of a vent in the roof. This sends any odors high in the air, making them quicker to disperse or be carried away. When drawing up garage grow room plans, be sure the walls go from floor to ceiling, unlike grow tents. This will allow you to run the exhausted air into the attic and out of the roof vent in a discreet, unseen manner.
Keeping your garage and cannabis grow room clean and safe
A clean grow room is one of the best ways to help reduce pest and pathogen levels. However, most garages have cracks and crannies where bugs and moisture can enter freely. Unfortunately, sealing your garage grow room entirely is challenging and uncommon. Plus, if you seal the garage grow room completely, you must still vent air into the space and replace CO2.
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Be vigilant by keeping dirt, dust, and insects to a minimum. If there was a large rain storm, ensure small pools of water didn’t collect next to the tracts on the garage door. Don’t do projects in the garage with chemicals that emit odors, like paint, gasoline, oil, etc. The cannabis flowers can absorb these smells, and it will ruin the flavor and terpene profile.
Above all, keep your grow secure and safe. It is normal for houses to have security cameras and motion sensor lights mounted above the garage. Do it. This adds a layer of security without sticking out or appearing excessive. If possible, exhaust from the roof or chimney, as this makes pinpointing a source more difficult for those on the ground. Don’t talk about your garage grow room; don’t share pictures.
Final thoughts
With a little effort, your garage can become a great place to grow cannabis indoors. It’s separate from the living area, which makes it an ideal option for parents. The configurations are only limited by your imagination and resources. You don’t even have to do much prep work, either. A few major tent companies offer tents as large as a 10ft x 10ft (3m x 3m) room if the goal is to have one big sealed area.
By building your own grow room in the garage, you won’t be bothered by the frequent sounds of dehumidifiers, air conditioners, or the whir of fans. There is no lack of plans online; in fact, our article, How to set up a low-budget grow room can get you started. Not sure how much space you need for the number of plants you desire? Have a look at our article – How many plants can you grow in a grow tent to find your answer.
What has your experience been with converting garages into grow rooms? Is there something important this overview is missing? Would you prefer to grow in a garage if you could? Please let us know in the comments below. Once your grow space is set up, learn how to grow amazing cannabis for free by downloading the Marijuana Grow Bible by Robert Bergman. Then select from our award-winning genetics, and you will be set for bountiful harvests. Happy growing!
Optimizing Your Grow Room Setup for Maximum Yields; In the ever-evolving world of indoor gardening, achieving maximum yields from your grow room setup is the ultimate goal for many cultivators. Whether you’re growing for personal use or running a commercial operation, understanding how to optimize your grow room setup can make a significant difference in the quantity and quality of your harvest.
From lighting and ventilation to nutrient management and plant training techniques, every aspect plays a crucial role in maximizing yields. In this comprehensive guide, we’ll delve into the key factors and strategies for optimizing your grow room setup to achieve bountiful harvests.
1. Choosing the Right Location
Before diving into the technical aspects of your grow room setup, it’s essential to select the right location. Ideally, choose a space that offers ample room for your plants to grow vertically and horizontally. Ensure the area has access to electricity, adequate ventilation, and is easily accessible for maintenance tasks. Additionally, consider factors such as temperature, humidity, and light exposure when selecting the location for your grow room.
2. Lighting
Lighting is one of the most critical factors influencing plant growth and yield in indoor gardening. Choosing the right lighting system tailored to your specific needs is crucial for optimizing yields. High-intensity discharge (HID) lights, such as metal halide (MH) and high-pressure sodium (HPS) lamps, have long been popular choices among growers due to their efficiency and effectiveness in promoting robust plant growth during both vegetative and flowering stages.
However, light-emitting diode (LED) technology has emerged as a game-changer in recent years, offering energy-efficient lighting solutions with customizable spectrums to meet the unique requirements of different plant species and growth stages. LED grow lights produce less heat, consume less energy, and have a longer lifespan compared to traditional HID lighting systems, making them an increasingly popular choice among growers aiming to maximize yields while minimizing operational costs.
3. Ventilation and Air Circulation
Proper ventilation and air circulation are vital for maintaining optimal growing conditions and preventing issues such as heat buildup, humidity fluctuations, and the spread of pathogens. A well-designed ventilation system should include exhaust fans to remove stale air and excess heat, as well as intake fans to bring in fresh air and maintain proper airflow throughout the grow room.
Installing oscillating fans strategically within the grow room helps improve air circulation and prevents the formation of microclimates, ensuring uniform distribution of temperature and humidity levels. Additionally, carbon filters can be incorporated into the ventilation system to eliminate odors and purify the air, especially in enclosed indoor environments.
4. Temperature and Humidity Control
Maintaining the right temperature and humidity levels is essential for optimizing plant growth and maximizing yields. Most plants thrive within a temperature range of 70°F to 85°F (21°C to 29°C) during the day and slightly cooler temperatures at night. However, specific temperature requirements may vary depending on the plant species and growth stage.
Similarly, controlling humidity levels is crucial for preventing issues such as mold, mildew, and pest infestations. Aim for relative humidity levels of around 40% to 60% during the vegetative stage and slightly lower humidity levels (around 40% to 50%) during the flowering stage to minimize the risk of bud rot and other moisture-related problems.
Utilizing dehumidifiers, air conditioners, and humidifiers can help regulate temperature and humidity levels within the grow room, ensuring optimal growing conditions throughout the entire cultivation cycle.
5. Nutrient Management
Providing your plants with the right balance of nutrients is essential for maximizing yields and producing high-quality harvests. Hydroponic systems offer precise control over nutrient delivery, allowing growers to tailor nutrient solutions to meet the specific needs of their plants at each growth stage.
When using soil-based growing mediums, selecting high-quality organic fertilizers and supplements can help enhance soil fertility and promote healthy root development. Regular monitoring of pH and nutrient levels in the growing medium is essential to prevent nutrient deficiencies or imbalances that can adversely affect plant growth and yield.
Implementing a feeding schedule based on the nutritional requirements of your plants and adjusting nutrient concentrations as needed throughout the growth cycle ensures optimal nutrient uptake and maximizes yields.
6. Plant Training Techniques
Employing plant training techniques such as topping, pruning, and low-stress training (LST) can help optimize light penetration, airflow, and overall canopy structure, resulting in increased yields and improved bud quality.
Topping involves removing the apical meristem (main stem) of the plant to encourage lateral growth and the development of multiple colas, resulting in a more bushy and productive canopy. Pruning involves selectively removing lower foliage and non-productive branches to redirect energy towards the growth of larger, more robust buds.
Low-stress training techniques such as bending and securing branches can help create an even canopy and promote the development of multiple bud sites, maximizing the potential for higher yields. Additionally, techniques such as defoliation during the flowering stage can further improve light penetration and airflow, leading to denser, more resinous buds.
7. Monitoring and Maintenance
Regular monitoring of environmental conditions, nutrient levels, and plant health is essential for identifying and addressing potential issues before they escalate and negatively impact yields. Invest in quality monitoring equipment such as pH meters, EC (electrical conductivity) meters, and thermohygrometers to keep track of essential parameters and make informed decisions regarding nutrient management and environmental control.
Maintaining cleanliness and hygiene within the grow room is also crucial for preventing the spread of pests and diseases. Regularly sanitize equipment, sterilize growing containers, and remove any dead or decaying plant matter to create a healthy growing environment for your plants.
In conclusion, optimizing your grow room setup for maximum yields requires careful consideration of various factors ranging from lighting and ventilation to nutrient management and plant training techniques. By implementing the strategies outlined in this guide and fine-tuning your cultivation practices based on the specific needs of your plants, you can unlock the full potential of your indoor garden and achieve bountiful harvests year-round. Remember to stay vigilant, adapt to changing conditions, and continuously strive for improvement to ensure consistent success in your indoor gardening endeavors.
Cannabis cultivation is an art that demands meticulous care and attention to detail to avoid Common Pests and Diseases in Cannabis Plants.
Among the challenges that growers face, pests and diseases rank high on the list of concerns. From tiny insects to microscopic pathogens, these threats can wreak havoc on cannabis crops if left unchecked. However, armed with knowledge and proactive measures, growers can effectively prevent and manage these issues.
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In this article, we’ll delve into some of the most common pests and diseases in cannabis plants, along with strategies for prevention and treatment.
Common Pests
Spider Mites: These minuscule arachnids are a nightmare for cannabis growers. They feed on plant sap, causing yellowing leaves, webbing, and stunted growth. Spider mites thrive in warm, dry conditions, making indoor grows particularly vulnerable. Regular inspection and the use of predatory mites or insecticidal soaps can help control infestations.
Aphids: These small, soft-bodied insects suck sap from cannabis plants, leading to distorted growth and the spread of viruses. Aphids multiply rapidly, making early detection crucial. Natural predators like ladybugs or lacewings can help keep aphid populations in check, while neem oil or insecticidal soap can be used for control.
Fungus Gnats: These tiny flies lay their eggs in moist soil, where the larvae feed on plant roots. Overwatering and poor drainage can exacerbate fungus gnat problems. Yellow sticky traps can help monitor adult populations, while reducing watering frequency and applying beneficial nematodes to the soil can control larvae.
Thrips: Thrips are slender insects that damage cannabis plants by sucking out chlorophyll, causing silver or bronze streaks on leaves and bud deformation. They can also transmit viruses. Insecticidal soap or neem oil can be effective against thrips, along with maintaining a clean growing environment to discourage infestations.
Whiteflies: These tiny, moth-like insects feed on plant sap, causing wilting, yellowing leaves, and the spread of mold. Whiteflies can quickly become a nuisance in indoor grows, where they thrive in warm temperatures. Yellow sticky traps and insecticidal soap can help manage whitefly populations, while introducing natural predators like Encarsia formosa can provide long-term control.
Common Diseases
Powdery Mildew: This fungal disease appears as a white powdery substance on leaves and stems, eventually causing them to wilt and die. Poor air circulation, high humidity, and crowded plant spacing can promote powdery mildew. Prevention involves maintaining proper ventilation, reducing humidity levels, and using fungicidal sprays containing potassium bicarbonate or sulfur.
Botrytis (Bud Rot): Botrytis cinerea is a fungal pathogen that thrives in cool, damp conditions, often affecting dense cannabis buds. Infected buds develop a grayish mold and emit a musty odor. Proper humidity control, adequate airflow, and diligent pruning of affected plant parts can help prevent bud rot. In severe cases, affected buds should be promptly removed to prevent further spread.
Root Rot: Overwatering and poorly drained soil create ideal conditions for root rot pathogens, such as Pythium and Fusarium. Affected plants exhibit wilting, yellowing leaves, and stunted growth. To prevent root rot, ensure proper drainage and avoid overwatering. Additionally, using sterilized growing mediums and maintaining a balanced watering schedule can help safeguard against this disease.
Leaf Septoria: Leaf septoria is a fungal disease characterized by brown or yellow spots on cannabis leaves, often surrounded by a yellow halo. It spreads rapidly in humid conditions and can defoliate plants if left unchecked. Prevention involves removing infected leaves, improving air circulation, and applying fungicidal treatments containing copper or sulfur.
Prevention and Treatment
Cultural Practices: Maintaining a clean and sanitized growing environment, proper plant spacing, and adequate ventilation are essential preventive measures against pests and diseases.
Integrated Pest Management (IPM): Implementing a holistic approach that combines biological controls, such as predatory insects, with cultural and chemical control methods can effectively manage pest populations while minimizing environmental impact.
Regular Monitoring: Routinely inspecting plants for signs of pests or diseases allows growers to detect problems early and take prompt action before they escalate.
Organic Remedies: Many growers prefer using organic treatments, such as neem oil, insecticidal soaps, and beneficial insects, to control pests and diseases while minimizing chemical exposure.
In conclusion, proactive prevention and early intervention are key to managing common pests and diseases in cannabis plants. By implementing a combination of cultural practices, integrated pest management strategies, and organic remedies, growers can safeguard their crops and ensure a successful harvest. Continuous vigilance and adaptation to changing conditions are essential for maintaining healthy and thriving cannabis plants.
Congratulations, you are about to begin your home gardening adventure. There are dozens of considerations to designing a custom grow room, from lighting to location to security, but don’t let that intimidate you. The ILGM family has your back with decades of growing experience in all sorts of garden spaces to help guide you through the process.
If you’re reading this, you’ve likely been looking at the different areas of your house and wondered, how do I convert this into a cannabis grow room?
This article will provide all the information needed to build an indoor cannabis grow room. Regardless of the available size, budget, or location, we’ve got you covered. Growing your own cannabis offers the rewards of saved costs and premium products if done correctly. ILGM wants you to succeed and to have fun doing it, which is why this article exists. Let’s get started!
Growing cannabis in a small space
Grow room designs exist for all sorts of footprints. How much space do you need? The best way to choose the ideal size is to determine how many plants you wish to grow. ILGM has hundreds of quality strains; unfortunately, we don’t have enough space to grow them all at once. You can find how many plants fit in different footprints by reading our article: how many plants can you grow in a grow tent?
Let’s say you want to grow a couple of small plants discreetly in an out-of-the-way location or windowsill in your home. Perfect; check out our article on cannabis micro-growing that will walk you through the considerations and steps to growing weed in a small space.
This article, however, highlights grow room designs for converting a larger space into a marijuana grow room.
Choosing the perfect room
Some growers can choose which room is best for them instead of making the only available option work for them. How do you decide? Well, outdoor growers have a saying – work with nature, don’t fight it. If your designs fit naturally into one room instead of another, choose the path of less resistance.
Cannabis plants grow best in the right environment, and temperature is one of those important variables. For example, if you’re deciding between a room with exterior, southwest-facing walls or one without exterior-facing walls, choose the second. It is much easier to keep the room in the middle of the house cooler than one that gets the afternoon sun.
The best cannabis grow room plans will utilize a room that growers aren’t afraid to do a little customizing in. Growing cannabis can be messy, although we preach cleanliness. The fact is, there will be soil spilled and water splashed onto the floor.
Rooms with concrete floors are ideal for cleanliness, but most people don’t have concrete floors in the house, only in the garage. You can sweep wood floors, but they can also absorb and retain moisture from spills. Rooms with carpeting can harbor pests and pathogens. Grow tents and drip trays can help mitigate these problems indoors.
Aside from the size, flooring, and location, there are still many things to consider when building a grow room; for instance,
Normal temperature fluctuations in the room (interior vs. exterior walls / north facing vs. south facing)
Average humidity in the room
Do windows need coverings to block light from escaping?
How many electrical outlets are there, where are they located?
Where will you exhaust the air?
Is it accessible to strangers, kids, or pets?
It is advised to have your vision for the grow room design and grow system worked out in your head before beginning construction. How to set up a grow room can be different for different growing styles. Hydroponic growers will need a water source in the room or very close to the room due to the requirements of that growing style.
Soil growers can walk down the hall to fetch water every few days without much inconvenience. Accounting for these small details will help you pick the right room to use. Below, we’ve highlighted the top three places to build a cannabis grow space in a house.
Attic grow room
This is one of the most underused spaces in the entire house. Attics are tucked above the main living areas, which adds discreteness to their potential as a marijuana grow room. Growers can customize this space to suit their needs, and ventilating the used air is as simple as connecting the fan to an existing vent.
Controlling temperatures can be challenging, and if you live in areas with annual snowfall, the bare patch on your roof might give your grow operation away. We go in-depth on the best ways to convert an attic into a cannabis grow room in our article – Attic Grow Room Tips.
Basement grow room
Whether you have an open floorplan or the basement is divided into different rooms, being below ground has advantages and disadvantages. This is another commonly underutilized area of the house that, with a little bit of preparation, can be turned into an excellent marijuana grow room.
The floors are typically concrete, there aren’t many large windows for light to leak from, and basements are a relatively secure area of the home. Extra equipment, e.g., dehumidifiers, may be needed to combat basement moisture, but everything is manageable. You can learn all you need to know about basement grow room plans in our article – Basement grow room tips.
Garage grow room
Another area of the home that, with a little customization, can make an excellent cannabis growing space. Smells, messes, and intense lighting are removed from the main living area, reducing a grower’s stress levels when company visits. Garages are also secured by locking doors, which can be ideal for growers with curious children.
Uninsulated garages will require work to mitigate temperature swings, humidity, and pests; however, they usually have adequate electrical outlets. Breaker boxes are commonly in garages, making installing a new outlet easier if needed. You can find the full list of pros and cons of growing marijuana in a garage in our article – Garage Grow Room Tips.
Equipment needed to build your grow room
For growers who like to make lists of materials and tools, the equipment needed to build a grow room can be divided into two sections: materials for construction and materials for growing. Obviously, you should purchase the materials for constructing your grow room first. However, remember that they both are coming from the same budget. It helps to have the big picture in mind.
If you are converting an existing room inside the house, most of the construction is already finished. My number one suggestion would be to buy a room-sized tent (8ft x 8ft [244cm x 244cm] or 10ft x 12ft [305cm x 366cm] ) or two large tents (4ft x 8ft [122cm x 244cm] ) for growers who want to run a perpetual garden. The large grow tent solution offers a drip tray for spills, reflective walls, and a frame to hang lights and other equipment.
If converting an open room, growers will need
a stud finder to locate ceiling joists to hang lights
white paint or mylar to increase the reflectivity of the walls
floor covering like tarps, linoleum pieces, or large drip containers that hold several pots
blackout curtains and velcro if the room has windows
Depending on the location and how well the walls are insulated, a few more items may be important. Items for controlling the environment, including
dehumidifier
humidifier
portable Air Conditioning
portable heater
circulating fans
To complete the picture, we’ve created an article for cost-conscious consumers titled – How to set up a low-budget grow room. In that article, you will find advice on lighting options, carbon filters, extraction fans, and many smaller accessory items. It also provides important factors for any grow space, such as being lightproof and airtight. But for those who have considered these things and are ready to move on, let’s get started with our design.
Make a grow room design
We shared a link earlier for determining the size footprint needed for the amount of plants that we want to grow. But how much light do we need to cover that space? That answer is in our grow light distance guide. Depending on the number of plants to be grown, you may not need the entire open space.
Gardeners who intend to grow only a few plants may benefit by planning their grow space in one of the corners. A corner placement allows more light to reflect from the walls back onto the plants compared to a few plants placed in the center of the room. You’ll want to access the plants from all sides, so add space for pathways around your plants. If space is tight, you may want to read our article about automatic watering systems for growing marijuana.
An overlooked aspect of grow room design involves electricity. Sharing the electrical load from grow equipment. Items like lighting, air conditioners, heaters, and dehumidifiers can require significant wattage from wall outlets. If a room has multiple outlets, design your plans to have these devices spread out. Consider which devices may be in use at which time. For example, although they both draw significant electricity, your air conditioning and heater are unlikely to run simultaneously. For more information about electricity in a grow room, check out our article – Electrical safety guide for growing marijuana indoors.
How to build your grow room
We’ve selected our room – three walls on the house’s interior and one exterior wall facing the front of the house. All the walls are properly insulated, so there is no need to make major corrections to the room. The full footprint of the room will be used for growing cannabis. Our first move will be to increase the reflectivity of the walls (and thus the efficiency of our light).
This can be done by painting them flat white or covering them with mylar. I prefer using the white paint option for a few specific reasons. The paint cost is lower than the cost to cover the same area using mylar or Panda film. You only need paint, a roller, a tray, some tape, and a tarp. You can also buy white paint with anti-fungal properties blended in; this is recommended.
Mylar and Panda film doesn’t cling to the wall surface; therefore, there are pockets of trapped air between the film and the wall. When there is an extreme temperature differential between the outside and inside of the wall, microclimates and condensation in those small pockets can lead to mold growth. This material is better utilized in smaller areas like micro grows.
Step 1: Wall preparation
Total Time Needed: 1 hour 30 minutes
It’s important to conceal your grow by covering any windows using blackout curtains and velcro. Light leaks and odors are the two most common signals that someone is growing marijuana.
Black curtains that are always closed may raise the suspicion of nosy neighbors. Instead, use blinds or a decorative curtain between the blackout curtain and the glass. This way, when people are looking at the window from outside, it looks just like all of the other windows in the house.
This relatively quick procedure can take up to ten minutes per window. You will need your special curtains, 1.5in (3.81cm) velcro, measuring tape, and scissors.
While the total time takes about 90 minutes in labor, it also needs to dry overnight.
01. Tape off any trim around doors, windows, and baseboards (20 minutes)
02. Place drop cloths on the floor in the area you are painting to protect the carpet or hardwood floor (5 minutes)
03. Stir your paint, pour it into a paint tray, and get your roller fully saturated (5 minutes)
04. Paint all four walls; the ceiling is usually already off-white and doesn’t need a fresh coat (50 minutes)
05. Allow the paint to dry overnight (ensure proper ventilation and air movement, open the window)
06. Remove tape from the trim, window, baseboards, and door (10 minutes)
Step 2: Window(s)
Total Time Needed: 20 minutes
Measuring and hanging your lights when the room is empty is typically easiest. Looking at your grow room design plan, you already know where the lights will be hung. In this design plan, we are hanging two lights spaced at an equal distance from the walls and each other in the center of the room. We’ve calculated the light dimensions and distances; now, we need to drill the holes.
We will need a ladder, a stud finder, a tape measurer, and a pencil to place our marks. To hang the light, we’ll need a drill, eye-bolts or J-bolts, and the chain or yo-yos that will attach our lights to these anchors in the ceiling. For a visual tutorial of these steps, visit our article about hanging grow lights.
01. Measure the size of the frame around the outside of the window (2 minutes)
02. Cut velcro into four pieces, top, bottom, left, and right (3 minutes)
03. Apply one side of the velcro around the window frame and the other side to the blackout curtain (5 minutes)
04. Connect the pieces and ensure there are no creases or gaps that can let light escape (3 minutes)
05. Turn off all lights in the room for five minutes and then check the velcro area for any leaks (7 minutes)
Step 3: Hang the light(s)
Total Time Needed: 30 minutes
01. Locate the joists in the ceiling in the rough position you wish to hang your light(s) using a ladder, stud finder, and pencil (5 minutes)
02. Lay your lights on the floor in the intended position, aligned with the newly found joists (2 minutes)
03. Stand back and ask – are the lights still centered over the intended garden area? (1 minute)
04. Measure the distance between the attachment points on the light fixture (2 minutes)
05. Mark that distance on the ceiling, in line with the joists that the light will hang from (5 minutes)
06. Use a drill bit with a slightly smaller diameter than the eye-bolt or J-bolt that will be used as an anchor. Drill a pilot hole through the drywall and into the stud for at least 1/2 the length of the anchor (5 minutes)
07. Insert the eye-bolt or J-bolt and tighten. Use a screwdriver or long instrument to place through the bolt for additional torque while tightening (5 minutes)
08. Use a tape measurer or count the threads to ensure both attachment points are equal distance from the ceiling (2 minutes)
09. Attach yo-yos to the anchors, extend them to the floor, and connect the lights (2 minutes)
10. Raise the lights to the desired position to verify accuracy, then raise them to the ceiling to get them out of the way for now (1 minute)
Want to read more about how to hang your grow lights in your grow room? Please take a look at our article about how to hang your grow lights here.
Adding ventilation to your grow room
With the lights hung but out of the way, it is time to construct the ventilation for the room. The window in this room faces the street, so that is not an ideal place to vent the air. If your space poses a similar problem, there are a few other options for venting.
The first option would be to seal the room and use a charcoal filter to scrub the air. A downside would be the need for supplemental CO2, which comes with added cost and equipment.
The second option is to cut a 6-inch (15.24cm) vent hole in the ceiling and exhaust the scrubbed air into the attic or out of a roof vent. In any scenario, the exhaust fan should exchange the air once every 1-3 minutes. To calculate the correct fan size for your room, calculate the room’s cubic footage / cubic meter (L x W x H) and select a fan with the appropriate cubic feet/meter per minute (CFM / m3/min) rating.
Exchanging and exhausting the air every 1-3 minutes creates a negative air pressure in the room, which will passively bring in fresh air and CO2 through the cracks in the room door. Long runs of ducting or ducting with numerous bends will decrease the stated CFM, so buy a fan with more power than you think you need.
For this design, we are going with the option of venting out of a roof vent. For this task, we will need our stud finder, tape measurer, bow compass, a jig saw, 6-inch (15.24cm) aluminum duct connector, ducting, worm gear duct clamps, J-bolts, string, carbon filter, and an exhaust fan.
Step 4: Room ventilation
Total Time Needed: 1 hour
01. Use the stud finder to find a good place in the ceiling between two joists to make a 6-inch (15.24cm) hole and mark it with a pencil and bow compass (8 minutes)
02. Cut the ceiling hole using the jigsaw (use safety glasses for protection) and insert the 6-inch (15.24cm) aluminum duct connector (10 minutes)
03. Use the stud finder to find a joist between your lights for mounting the carbon filter and fan (2 minutes)
04. Drill the pilot holes and insert your J-bolts (5 minutes)
05. Hang the carbon filter and fan. Smelly grow room air will be sucked through the carbon filter and exhausted through the ducting into the attic (5 minutes)
06. Map the route from the fan exhaust port to the hole in the ceiling. Locate the ceiling joists along that route and place a J-bolt every 3ft (91.5cm). (5 minutes)
07. Use string to attach the ducting to the J-bolts in the ceiling along the route running between the output end of the fan to the 6-inch(15.24cm) aluminum duct connector in the ceiling. (10 minutes)
08. (Bonus) Go into the attic and attach ducting to the 6-inch (15.24cm) aluminum duct connector popping up through the drywall. Attach this ducting to a roof vent, and now all of the cleaned air is released into the atmosphere for further dissipation (15 minutes)
Setting up fans
Moving air within the grow space is also essential to grow room design. Air movement is crucial to reduce micro-climates within the canopy, areas of stale moist air in the corners, and to strengthen branches so that they can support heavier buds. One of the well-known reasons to move air around the grow space is to reduce the opportunities for powdery mildew (PM) to land and grow on your plants.
Place circulating fans on small stands, mounted to the walls or on the floor. At a minimum, you’ll want one fan moving air at the canopy level and another fan moving air below the canopy.
If you have a large room, fans may need to be placed on both sides of the room to ensure the middle section is getting good air movement. For a deeper understanding of the mechanics behind this and why good airflow is important, check out our article on Managing Airflow.
Step 5: Room circulation
Total Time Needed: 10 minutes
Remember to move air both above and below the canopy.
. Place a fan in the corner (fans mounted to walls will create vibrations and low-frequency noise. This is not ideal if you have neighbors on the other side of that wall) and turn it on to a normal speed. Walk away from it; how far does the air push? (4 minutes)
02. Set up a fan on the opposite side of the room and turn it on. Do the two create enough air movement in the center? (4 minutes)
03. If satisfied, set the fans to oscillating and ensure that their spread is enough to reach the corners of the room (2 minutes)
Controlling temperature and humidity in your grow room
An advantage of using a room inside a house is that the temperature will generally be in an acceptable zone. There may be the need for cooling in the summer and a little added warmth in the winter, but for the most part, temperatures are controlled already. Most houses, however, don’t have features built-in to control humidity.
Small dehumidifiers meant for tents, RVs, and closets will not impact the humidity levels in a large room full of transpiring cannabis plants. Growers will need to invest in the 30 or 50-pint dehumidifiers. Conversely, humidifiers should have a large enough reservoir that they don’t require filling every few hours. Learn more of these important details in our article – Create the best climate for marijuana grow room.
Step 6: Climate control
Total Time Needed: 10 minutes
Because these devices draw significant wattage from the wall, avoid using them on the same outlet as the grow light if possible.
01. Determine the square footage (square meter) of your room by multiplying the length x width (2 minutes)
02. Select a dehumidifier and/or humidifier that exceeds the square footage (square meter) of the room, preferably doubled (8 minutes)
Safety and fire prevention
The first rule in grow room safety is to have multiple smoke detectors in the garden space. I prefer one close to the lights and another near the canopy level.
A licensed professional should conduct any and ALL electrical work. Never “wing it” with electricity.
Do not place power strips or electrical connections on the ground where water can be spilled onto them; keep them elevated.
If you have to use extension cords, the shorter, the better; don’t leave large coils of extension cords around.
Keep any flammable materials away from the grow lights. This includes curtains, cords, and vegetation.
Always keep a fresh fire extinguisher at the entrance of the indoor grow room.
Use tape or twist-ties to secure loose cords to reduce tripping hazards.
Cleaning your grow room
“An ounce of prevention is worth a pound of cure,” goes the saying. It essentially means it is easier to prevent something than it is to repair the damage. This sentiment holds true to professional growers’ integrated pest management (IPM) strategies. Indoor grow rooms should always be free of loose soil, standing water, and leaf material. During a full grow cycle, there may be some stains on the floor or dirt accumulated in the corners. It is good IPM practice to clean the room between each cycle.
Cleaning products specific to cannabis grow rooms can be purchased, but the common cleaners are diluted bleach or cleaning vinegar. Wipe down everything from the walls to your soil containers to the shovel you use to scoop soil. Indoor grow rooms with a recent pest infestation should take extra measures, which may include not growing for up to a month to break the unwanted pests’ life cycle. You can learn more of these crop-saving tips in our article – How to Clean Your Grow Room.
Final thoughts on building a grow room
Designing a custom grow room for cannabis can be exciting. Now that you’ve read this article, you should know the many aspects to consider when designing a grow room and have the knowledge and confidence to make those choices.
If faced with a large blank canvas like an open room inside the house, I would use large grow tents instead of customizing the room. That is not always an option for growers due to availability or budget, and that is why we’ve created this article for designing an indoor grow room.
Remember, different areas of the house can call for different construction materials, tools, and techniques. Fortunately, we have specific articles for each of the main areas people grow. We also cover how to build a DIY grow tent if that is your preference. Regardless of where you decide to grow, for security purposes, cover the smell, block the light, and reduce mechanical noises that can give your grow away.
Designing the right grow room today can be the reason for future success. When a cannabis grow room is dialed in, all you need to do is grow like a pro. If you want to grow like a pro, all you need to do is download Roberts Grow Bible for free and get started on becoming a master grower.
Please let us know if you found this article or any other linked articles helpful in planning your grow room. Is there something we missed? We’d love to read your thoughts in the comment section. Have fun with your design plans, and happy gardening!