Indoor cannabis growing is the safest, most productive way to grow marijuana. It gives you total control over feeding, water quality, temperature, humidity, lighting, air movement, root zone and irrigation timing for robust crop growth.
Perhaps the most basic choice an indoor grower must first make is what type of hardened enclosure the grow op will be housed in. Let’s take a look at the choices, plus the pros and cons of each type of setting commonly used for growing cannabis indoors.
(Please note that I’m not including attics on this list due to the heat and fire dangers they present when utilized as a grow op.)
Growing Cannabis In Bedrooms
Many growers take a spare bedroom or other room in their house or apartment and turn it into a grow room. While these rooms are likely to have windows, they should certainly have lockable doors.
It’s best if they have no external wall that receives direct sunlight, especially in the afternoon. Plus, it’s ideal if the grow room can be equipped with a split-unit wall-mounted air conditioner.
Most rooms of this type typically measure 110–250 square feet — large enough to run a professional grow op. At the upper end of the size scale (200–250 square feet), and provided you have sufficient air conditioning, venting and electrical capacity, you can run several thousand watts’ worth of grow lights and harvest upward of six pounds per season.
While this grow-room option offers perimeter security and convenience, it also has its disadvantages:
- Growing in a room inside a home means anyone who lives in the home or visits could easily uncover your grow op.
- If you have children, it’ll be tricky if not impossible to keep them out of your grow room.
- The grower usually has to significantly modify and retrofit walls, ceilings, windows, doors and electrical supply of a room to make it suitable for cannabis cultivation. The costs can quickly add up, while the alterations can affect dwelling safety and negatively impact the value and resale potential of your property.
- If you’re a renter, an indoor grow room is almost always a violation of the rental agreement, and any modifications you make to the room will likely cost you your security deposit.
- Growing indoors creates heat and humidity that affects the whole building’s climate control system.
- Indoor grow rooms that are improperly run may host mold, mildew and pests that affect human health and comfort.
- Indoor grow rooms require fans and equipment that generate substantial amounts of telltale noise and vibration.
Growing Cannabis In Basements
Basements are common features of homes in some regions of the US, and offer many benefits to marijuana cultivators who are repurposing them as grow rooms.
A finished-basement grow room with sufficient odor control and noise dampening can be so stealthy that people on the upper floors of the dwelling will likely have no idea there’s a grow room lurking below.
Basements are usually much cooler than the upper floors of the home, which means heat from grow lights is mitigated more easily. Basements can be clandestinely vented, and there are usually no windows that allow light from grow lamps to escape.
Not only that, basements can be pitch black during lights-off cycle, and if properly sealed and climate controlled, they’re virtual fortresses that block out such pests as spider mites, broad mites, thrips, aphids, fungus gnats, whiteflies and root aphids.
Basement grow ops also offer extra security that protects growers against thieves and law enforcement. There are, however, disadvantages to running a basement grow room, including:
- Basement floors are usually cold, which can damage cannabis roots.
- Basements almost always need a sump pump and dehumidifier to remove ground water and humidity. This requires a 100 percent constant electricity supply in the form of a vented generator.
- Poorly ventilated basements and those without adequate climate control can be a host for molds and mildews.
- Basements might be too cold for cannabis, especially during winter and lights-off cycle.
- Basement stairs are a potentially unsafe obstacle. Many a grower has suffered strains and injuries while lugging gear, bales of soilless mix, and grow lights up and down basement stairs.
- Many basements are unfinished. To that end, most growers will have to make a substantial investment in plumbing, wiring, circuit panel upgrades, venting, paneling, insulation and drywall to make the basement a worthwhile place for growing marijuana.
- A basement is where you’ll likely find the dwelling’s infrastructure for water heaters, air handlers, water pipes and water mains, electrical panels and washer-dryers. Should this equipment need servicing, the presence of a grow op in the basement presents something of a security risk dilemma.
Growing Cannabis In Your Closet
My first cannabis grow op was in a closet. I followed the instructions mapped out in Ed Rosenthal’s cannabis grow book Closet Cultivator.
I used a 250-watt high intensity discharge fixture, a metal halide bulb for grow phase, and a high pressure sodium lamp for bloom phase. I hung the grow light from the clothing dowel.
The closet measured a little less than four square feet. There was no way to ventilate it. The plants didn’t do well and I vowed to never do a closet grow again.
The only successful closet grows I’ve seen were in large walk-ins, and even this isn’t an ideal environment for cannabis cultivation.
The disadvantages of closet cannabis gardens are numerous and include:
- Heat buildup and no easy way to remove heat or deliver cooled air.
- Limited horizontal and vertical space.
- Potential for excessively high humidity.
- Difficult to access and tend to plants.
- Difficult to prevent light leaks.
- Light, noise and heat infiltrating the larger room that the closet is in.
Growing Weed In A Detached Garage Or Outbuilding
Outbuildings do not include greenhouses, because they usually aren’t hardened and completely sealed off from the outside world, so they lack the sturdiness and proximity control necessary to meet the definition of indoor cannabis growing.
Garages attached directly to houses are sometimes used for indoor growing, but not often, because they present multiple difficulties, including:
- A garage grow room supplants the use of the space for its intended purpose of protecting vehicles and housing infrastructure and equipment.
- A garage adjoining the house is less secure than a room in the house and can be especially insecure if the garage door is old, manually operated or defective.
- Most house-linked garages aren’t plumbed or equipped with electrical wiring and insulation sufficient to support an indoor grow op.
Detached garages and purpose-built outbuildings, on the other hand, offer you the chance to custom design an ideal space for your grow op.
Successful home growers tend to live in a house on a relatively large property and have built a customized and detached grow room behind their home within a fenced yard, so the detached grow structure isn’t visible from the street or from beyond the property line.
When you plan and build your ideal detached grow-op structure, this removes the hassle of having to retrofit an existing room. You make the sealed structure exactly what you need it to be. This can include:
- Concrete-reinforced thick walls.
- Extra insulation.
- Solar power or a separate municipal power grid and generator to handle the high-watt, high-amp draw of growing.
- Split unit air conditioner.
- Vector filters and fans.
- Odor controls.
- Built-in light movers.
- Reverse osmosis units.
- Steel doors for added security.
- Security cameras and motion sensors.
The customized grow op will ultimately save you money, increase yields, protect plants from pests and diseases, and provide a near-perfect indoor environment that’s more difficult to duplicate in a house or apartment.
The detached structure won’t be inside your home, so visitors aren’t going to see or smell your cannabis. And children need never know what’s in the detached structure at the bottom of the backyard.
However, there are a handful of disadvantages for growers choosing a detached structure for their grow room:
- If you want to be legal, you have to get a construction permit and code inspections. Many municipalities are bureaucratic and will make this process costly and time-consuming. Inspectors may also ask you what is the intended purpose of the structure.
- Because the unit isn’t attached to the main dwelling and may be located far from your home (if your property is large), it’s not as easy to know if someone is tampering with your detached grow op.
- The cost of constructing a detached structure, even if you do all the labor yourself, can be at least $3,000 and in some cases much higher than that.
- If a detached garage or structure is already extant, the costs and hassles of retrofitting it as a grow room can be as high as retrofitting a room inside the house.
- Unless you go rogue and build the detached grow op without getting building permits and inspections, the building can add to the assessed value of your home. As a consequence, this can raise property taxes and homeowner insurance costs.
Indoor cannabis growing is worth the time, cost and labor to create a private, lockable, purpose-built space for your crops. For those who rent an apartment or condo, it’s wise to give prudent consideration to location, type and design of your indoor grow room.
When it comes to at-home grow ops, a basement is by far the better option compared to a room on an upper floor with common traffic, while a detached building is even better.
In my experience, the most successful, productive, security-savvy grow rooms are those found in basements and detached, purpose-built structures. And for growers who have children at home — or would like to have a somewhat normal social life — my advice is to not have a grow room inside your home at all.