This may be your first time growing cannabis, or you might be relatively experienced but in need of a reminder about some of the stuff involved in successfully growing your cannabis crop.
Either way, you’ll find out what you need to find out right here in this article:
How to Grow Cannabis Indoors – The Ultimate Beginners Guide to Indoor Growing Systems.
I’ve broken this cannabis-growing guide into clear-cut sections that are easy to follow. Ideal for the novice cannabis grower.
With that said, it’s time to dig in!
(Incidentally, this post contains links to products. Please make the assumption that at least some of the links may result in earning commissions. Thank you.)
Step 1: Designate a space or grow room for your cannabis crop
The space that you select to grow your cannabis crop does not need to be large.
The space where you wish to grow your cannabis crop does not need to be much like what you’d expect a typical grow room to look like.
You can use a closet; you can use a cabinet; you can use a spare room; you can use a tent as your cannabis grow room; you can use an area in your basement.
Whichever space in your home is right for you, you’ll want to remember that the equipment you choose, and the plants, will have to be tailored in order to fit the space – particularly if the space is very short in supply.
If this is your first cannabis-growing project, there are a few reasons why starting out small is wise policy:
- It’s cheaper to start out small.
- It’s simpler to start out small – fewer plants to monitor.
- As a first-time cannabis grower, it’s likely you’ll make mistakes. Those mistakes are less costly with only a few plants to cater to.
At the same time, you should be thinking big (or at least “bigger”)…
When designating your grow space, don’t forget that you are not only accounting for the plants – you also need to account for the lights, the fans, the ducting, and various other equipment.
You’ll also need a bit of room to work in.
Your plants, throughout the stage of early flowering, can double and possibly triple in size.
That said, you need to have plenty of space overhead for this level of expansion.
If you’ve set up your cannabis grow room in a small closet, in a tent, or in a cabinet of some kind, you only need to remove each plant individually to work on it.
Otherwise, you’ll have to be sure to leave some space to work in.
Your Cannabis Growing Space Must be Clean
Your growing space must be easy to sanitize.
It’s particularly important when growing indoors that your growing area is always clean.
Surfaces that are easy to sanitize are a must.
Drapes, raw wood, and carpeting are not easily cleaned, so they are best avoided.
How to Sanitize Your Cannabis Growing Area
Prior to planting:
Your supplies may be new or they may have been used before. Either way, they should be thoroughly cleaned.
Tools, pots, tubes – they should be free of dirt and dust given that microbes feed on dirt and dust particles.
That said, wash pots and tubing with hot, soapy water. Rinse thoroughly. Make sure everything is totally dry before use.
For tools, it’s best to use isopropyl alcohol to disinfect.
Organic matter in soil can prove to be a host to fungi and various other contaminants. It’s best to begin every grow using a sterile mix.
To reuse soil sterilize it in a kitchen oven at 180 degrees F/ 82 C for around 30 minutes. Simply spread the substrate onto aluminum baking foil which is placed over metal baking pans at a depth of 4 inches/ 10 cm or less.
If your plants come from someone else, it’s wise to quarantine them for at least a week before they are introduced to your growing room.
Be vigilant for any signs of pests and/ or disease on new plant arrivals.
At growing time:
The solution you feed your plants with is a harbor for all kinds of fungi. If you spill any of the nutrient solution onto the floor or elsewhere, wipe it up fast.
A grow room’s humid environment is perfect for mold, algae, and mildew.
If you see any, remove it with a sulfur-based fungicide – a fungicide that has gained approval to be used in organic gardens. The image below depicts a good sulfur-based fungicide for use in organic gardens.
Actually, algae are best removed with copper sulfate.
For various reasons, introducing external air into your grow room is vital. However, exterior air can bring unwanted organisms with it.
That said, you can use HEPA filters by placing them over your ventilation devices. However, that’s not an overly effective solution. Rather, air purifiers are best, but with a good air purifier comes a ‘good’ price tag. So, a good quality air purifier for a decent price is the COLZER Air Purifier with True HEPA Air Filter. The Colzer purifies an area of up to 425 square feet.
After the growing cycle has come to an end, all of the surfaces and all of your supplies should be thoroughly cleaned.
Get rid of any bits of plant matter too since these are feeding and breeding grounds for fungi and plant pathogens.
Use something like hydrogen peroxide which in chemistry is denoted by H202. The 3% solution or the 6% solution is an ideal concentration to use at full strength to swab your grow room surfaces.
Anything higher than a 10% hydrogen peroxide concentration should be avoided because it can harm your skin as well as your plants.
A Light-Tight Cannabis Growing Space
Besides sanitization matters, your growing space must also be light-tight.
Any light leakage during periods of dark (when your cannabis lighting is turned off) will only serve to confuse your plants. Yes, even plants can become confused.
This confusion then leads to the production of male flowers, which is not necessarily what you want.
Why the emphasis on the word necessarily? Well, it’s because male cannabis plants do have their uses. Most cannabis growers chuck male cannabis plants in the trash. But that’s not advisable.
So, what are the uses of male cannabis plants?
Very much in brief because if you’re new to the cannabis growing pursuit it’s best to limit information to what you really need to know right now.
Male cannabis plants are useful for:
- Quality male cannabis specimens are required – totally required – for a cannabis breeding program to be successful.
- It is generally thought that male cannabis plants contain zero cannabinoids. That is, in fact, untrue. Male plants do contain cannabinoids though at a lesser level than female plants.
- Male cannabis plants can be used for the production of raw juice. Hence male plants can be juiced in order to derive benefit.
- Male cannabis plants can make for good companions. Yes, indeed so. Dried cannabis leaves and dried cannabis flowers have been used for a long time to make pesticides due to their repelling constituents. Therefore, they can be planted with other plants to repel certain pests.
Other Cannabis Growing Space Variables to Consider
When you’re trying to come up with a suitable area for your cannabis crop to grow, keep these variables in mind:
Humidity and Temperature
If the space you choose to grow your plants is already humid or particularly warm, it’s not necessarily going to be simple to control the environment for optimal plant growth.
It’s highly recommended to select an area that is dry and cool. An area that has access to copious fresh air – preferably from the outdoors.
Your cannabis crop should be frequently and carefully monitored.
How frequent is frequent?
Check every day, several times each day.
If you’ve chosen a growing space that is difficult to gain access to, checking your crop frequently is going to be problematic.
Sounds like something the armed forces would be involved in.
However, in this case, we are talking about concealment. Nothing to do with guns, either.
Nosy neighbors can potentially be a problem for you.
Theft can also be a problem – it does happen, and it happens often.
A friend of mine recently had a large crop of cannabis growing in a glasshouse at the base of her garden.
That’s not a bad thing in terms of keeping nosy neighbors at bay – it was a large garden and the glasshouse was well away from houses.
Nevertheless, a number of folks became aware of this glasshouse-growing operation, and it became a target for theft.
Indeed, very early one morning, all her plants went awol.
Step 2: Which Cannabis Grow Lights are Best for You?
When it comes down to quality of plant yield and quantity of plant yield, it’s mostly down to the lighting.
This means you should try to get the best cannabis lighting you’re able to afford.
Here’s a list of the optimal cannabis grow lights that are suited to indoor growing.
High-Intensity Discharge lights – HID – are regarded as industry standard.
Because they combine quality output with good value, and also efficiency.
While they are more costly than fluorescent and incandescent fixtures, HID lighting caters to much more light in terms of the number of electrical units consumed.
Notwithstanding, HID lighting in comparison to LED lighting is not as efficient.
But, for a comparable unit, HID lighting fixtures cost around one-tenth that of LED lighting fixtures.
There are two types of HID lamps that are most popular among growers:
HPS (High-Pressure Sodium): light from HPS is more toward red-orange in the spectrum. Utilized during the flowering stage. Besides the bulbs, you need a hood/reflector and ballast for each individual lamp. Many of the newer ballast designs work with both HPS and MH (metal halide) bulbs.
MH (Metal Halide): the light from MH is blue-ish white in color. Generally, MH is utilized to encourage vegetative growth.
If you’re struggling to afford both HPS and MH bulbs, it’s best to start out with HPS alone.
HPS delivers more bang for your buck – more light per unit of electricity/ watt.
HPS bulbs also remain cooler, they are more efficient, and you’ll not have to replace the bulbs as often.
Don’t be tempted to purchase a cheaper-end digital ballast.
The problem with cheaper digital ballasts is the shielding is not that good. What’s more, they can also create electromagnetic interference. This interference has an impact on WiFi and radio signals.
If you’re going to grow in a large, open area – an area that comes with plenty of ventilation, then you’ll likely not be in need of air-cooled reflector hoods.
Otherwise, though, you (and your plants) will definitely benefit from them.
Air-cooled reflector hoods are used to mount the lamps inside.
These are necessary because HID bulbs get very hot.
In turn, air-cooled reflector hoods call for ducting as well as exhaust fans.
While this obviously increases initial cost and hassle, they do work very well in controlling the growing space temperature.
Among the very best air-cooled reflector hoods currently available is the Sun System Grow Lights hood. Decent price too.
Among smaller-scale hobbyist growers of cannabis, fluorescent light fixtures are particularly popular – more so with the HO (high-output) T5 bulb.
There are a few reasons for this popularity:
- Cheaper: The bulbs, the ballast, and the reflector are all included within a single kit.
- No cooling system necessary: Fluorescent bulbs, while they do get warm, are not nearly as hot as HID bulbs.
There is a downside to fluorescent. In fact, there are two downsides.
They’re not as efficient as HID.
Per watt of electricity consumed, fluorescent generates around 20-30 percent less light than HID.
Then, if you want light output that is equivalent to one single HPS bulb which is 600 watts, you’d need about 19 x four-foot T5 HO bulbs to achieve it.
Again, fluorescent is suited to the very small-time grower.
Light-emitting diode technology is certainly nothing new.
Nevertheless, only fairly recently has this technology been adapted in such a way that we are now able to use LED for indoor growing. And it’s extremely efficient.
There is, as usual, a drawback.
They cost a lot.
For an LED fixture that is well designed, in comparison to the HID counterpart, and you’re looking at around 10 times the cost.
But, there’s a further benefit to LED. Or a bunch of benefits, actually…
- They last far longer than HID.
- They utilize far less electricity.
- They don’t create nearly as much heat.
- Better LED designs offer a fuller lighting spectrum than HID. In turn, that generally leads to greater crop yield and better cannabis quality.
Be aware that many manufacturers produce second-rate LED lights and market them towards growers.
That said, it’s wise to do a bit of research before you make any investment in an LED setup. Check out some customer reviews, for example.
The induction lamp (also referred to as electrodeless fluorescent), while it is certainly far from being a new technology (it was invented in the late 1800s by Nikola Tesla), has been adapted to fit in with indoor growing requirements.
Essentially, induction lamps are longer-lasting, more energy-efficient formats of fluorescent bulbs.
Drawbacks include – not being easily available and high price tag.
Step 3: Airflow for Indoor Cannabis Plants
In order to thrive, all plants need plenty of fresh air.
For the photosynthetic process (cell generation), plants need carbon dioxide.
As such, your cannabis crop will want a constant supply of air within and flowing through, your growing space.
You can achieve this goal by installing an exhaust fan at or near the top of your growing area. This, the exhaust fan, will serve to remove warmer air.
You also need an inlet for filtered air which should be installed at the opposite side of your growing space.
Temperatures inside the growing space should be maintainable.
Ideally, you’ll want anything between 70 F (21 C) and 85 F (30 C) whenever the growing space’s lights are on.
And you’ll want anything between 58 F (14 C) and 70 F (21 C) when the lights are turned off.
There are some cannabis varieties (more so strains of indica) that much prefer temperatures to be at the lower spectrum of these ranges.
The exhaust fan’s size will be dependent upon the size of your growing space, in addition to the lighting system and how much heat it generates.
Larger exhaust fans will be needed for HID lighting systems.
For those who reside in warmer climates, you would likely be best running your lighting system through the night.
In this way, the temperatures of your growing space are more easily maintained within the required spectrum.
Cannabis plant odor can be a problem, too.
If it is a problem for you (e.g. nosy neighbors may come a snoopin’ because of the odor), you can install a charcoal filter within your exhaust fan. That – the filter – should reduce the odor significantly.
If possible, try to maintain a persistent breeze within your growing space.
What this does is to strengthen the stems of your plants.
A light breeze will also establish a growing environment that is less hospitable to flying pests and mold.
You can wall mount a circulating fan for this purpose.
Avoid pointing the fan straight towards the plants, however, as this encourages windburn.
Step 4: Controls and Monitoring System for Cannabis Growing
After you’ve chosen the lights for your cannabis growing space as well as the climate control equipment, it’s imperative to get them to function on auto.
There are very costly and highly sophisticated units that are available to control the lighting, the temperatures, the humidity levels, and the carbon dioxide levels.
Fortunately, the novice grower doesn’t need that level of functionality.
Instead, the beginner can make do with an adjustable thermostat to control the exhaust fan and a simplistic 24-hour timer for the lights.
For all cannabis growers, the light/dark cycle timing is very important.
During the vegetative growth stage, for every 24-hour period, normally, you’ll want your lights on for around 16-20 hours.
Then, during the blooming stage, you can tone the lighting down to around 12 hours light for every 24-hour period.
To avoid stressing the cannabis crop, your lights must go on and go off at the same times each and every day.
You can, if you wish to save a little money, install a timer to control your exhaust fan.
But for just a few extra bucks, a far better option is to install a thermostat switch.
For very basic models, all you need to do is to set the thermostat to your desired maximum temp. Then you plug the exhaust fan into the thermostatic device.
Upon the temperature in your growing space rising to the set level on your thermostat, the fan will go on.
The fan will remain on until the pre-set thermostat threshold has been reached.
Not only does this maintain a steady temp in your growing space, but it also saves a lot of energy – aka, money.
A combo hygrometer/ thermostat that comes with a high/ low memory is very useful to keep a tab on your growing space’s conditions.
These devices are cheap and while they display current temperature as well as humidity, they will also display highest and lowest temp and humidity levels since the time of your last viewing.
Among the best thermostat switches is the Inkbird All-Purpose Digital Temperature Controller. Fortunately, it’s one of the cheapest as well.
If you’ve got a pH meter to hand, you can check the soil, nutrient solution, or water pH.
(I’ll discuss different cannabis growing media in the next step.)
This is valuable since cannabis plants prefer a pH that is somewhat acidic – at a level of between pH6 and 7 – if your growing medium is soil.
If you utilize a hydroponic growing media, the pH should be between 5.5 and 6.5.
You shouldn’t allow the pH to rise above or drop below these levels.
If you do, you’ll encourage what is referred to as “nutrient lockout.”
What this means is that your cannabis crop will be incapable of absorbing the necessary nutrients, leading to the eventual death of the plants.
For this reason, you should test your growing medium’s pH regularly.
If you can find a pH meter that will test soil pH and solution pH please let me know. For now, I can recommend this digital pH meter for water and nutrients.
And the Besmon pH meter for soils and other substrates. The Besmon also tests for soil moisture which could prove to be very handy.
Step 5: Which Cannabis Growing Medium is Best for Your Needs?
No matter which type of growing media you choose for your cannabis crop, each of them come with their pros and their cons.
Soil for Cannabis Plants
Soil acts as the most forgiving indoor cannabis growing media.
This makes it ideal for the first-time cannabis grower.
As long as there are no slow-release fertilizers (example: Miracle-Gro) in the potting soil that you buy, you’ll be good to go with almost any type of potting soil.
For the beginner, a fine choice of potting soil is what is referred to as “super-soil.”
Super-soil is an organic potting soil that is pre-fertilized.
It’s ideal for cannabis plants because you can grow your crop from the very beginning to the very end without any need for further nutrient addition.
Super-soil can be purchased from various suppliers. You can also invest in a cannabis-specific super-soil named Booyah. With Booyah, you can mix it with other soils or use it alone.
Garden soil is inappropriate for the purpose of growing indoor cannabis plants.
The reason is that, first, the soil’s consistency may be entirely wrong, and second, the soil can be riddled with pests and/ or diseases.
Hydroponics for Cannabis Plants
Soil-less or hydroponic media is becoming an ever-more popular choice for cannabis growers.
Hydroponic systems require feeding with a concentrated solution of mineral salt nutrients.
These nutrients are directly absorbed into the root system by osmosis.
In turn, this leads to more rapid plant growth and larger yields.
All the same, it calls for a high level of precision given that your crop will react fast to under- or over-feeding.
Plants are far more susceptible to lockout and nutrient burn in a hydroponic system than they are in a soil-based growing media.
The various materials used in hydroponic growing systems include vermiculite, coco coir, expanded clay pebbles, rock wool, and others.
Soilless mediums can either be hand-watered or can be set up with automated hydroponics for the more sophisticated system.
Step 6: Containers for Indoor Cannabis Plants
The type of container you choose to use for your cannabis crop is dependent on the growing medium and your overall system type.
With a super-soil system, you might prefer to rely on 10-gallon pots and simply grow a few large-sized plants.
The Vivosun 5-Pack Plant Grow Bags are available in an array of sizes, including 10 gallons.
With a tray-style, flood-and-drain hydroponic system, you might prefer to have small-sized net pots filled with clay pebbles. Otherwise, you could use large slabs of rock wool.
Besides 10-gallon pots, other inexpensive growing solutions include cloth bags or perforated plastic bags.
There are many folks that prefer to invest in five-gallon plastic buckets.
In this case, you will need to drill holes into the base of each bucket and stand them off a flat surface so the water can, indeed, drain out successfully.
Cannabis plants DO NOT like water-logged soil around the root system.
Plastic buckets are a more expensive option than the Visosun pots mentioned above.
Step 7: What Nutrient Feed is Best for Indoor Cannabis Plants?
For a high-quality cannabis crop, you’ll need to provide more nutrients (fertilizer) than you would with most other types of crops.
The primary nutrients (macronutrients) that are required by all plants for healthy growth are nitrogen (N), phosphorus (P), and potassium (K).
There are also a variety of micronutrients that are required, though in far smaller quantities than the macronutrients.
The key micronutrients for cannabis plants are copper, calcium, iron, magnesium.
If you prefer not to use a soil-based growing medium that is pre-fertilized, and instead, you opt for hydroponic, your cannabis crop will need to be fed at least once weekly with the appropriate nutrient solution.
You can buy the appropriate nutrient mix in powder form or in liquid form.
Both powder and liquid nutrients should be mixed together with the right amount of water.
They can be formulated to suit either the vegetative growing stage or the flower-production stage.
Cannabis plants require more nitrogen during their vegetative stage of growth (the initial stage).
Throughout the bud production stage, the plants need a higher amount of phosphorus as well as more potassium.
There are some strains of cannabis that need more in the way of calcium together with magnesium than do other strains.
If the strain you are growing does want more of these micronutrients (the person/ business establishment that sells you the seeds should inform you about this), you can invest in a Cal/Mag growing supplement.
After you make your purchase of the required nutrient products, you simply follow the directions on the label.
But, be sure to start out with only half the recommended strength.
That’s because, with a full-strength feed, you could burn the roots of your crop.
The general rule is that it’s much worse to overfeed a crop than to underfeed.
Step 8: Watering Your Cannabis Crop
For most of us, we don’t think much about the water we use to water our plants.
We have a tendency to believe that if you can drink water, it should be fine for plants.
Depending on where you reside, this matter may not be of concern.
But, some water consists of a high level of dissolved minerals.
These dissolved minerals, when added to a crop such as cannabis, have a tendency for building up in the root zone.
In turn, that has an adverse impact on nutrient uptake.
What’s more, the water could contain fungi or a variety of alternative pathogens that cause humans no harm at all but could prove to be harmful to plant life.
Then, on top of that, tap water frequently contains chlorine at quite high levels.
Chlorine is not at all good for soil microbes that are beneficial to cannabis plants.
So, for all of the above reasons, those in the know prefer to utilize rainwater as opposed to tap water or any other type of water.
Also very important with regards to watering your cannabis crop is to always avoid overwatering.
Cannabis has a high level of susceptibility to fungal root diseases.
And these diseases can become rampant when overwatering occurs fairly often.
The frequency of watering a cannabis crop depends on the type of medium, the plant size, and the ambient temperature in your growing space.
Many of the more experienced cannabis growers prefer to avoid watering their plants until they notice some of the lower leaves starting to droop.
This drooping is brought about by a need for water, so it’s a very good sign.
As you become more experienced in growing cannabis, you will make changes to your grow space and to your equipment.
You’ll make these changes to fit in better with your growing environment, with your individualized techniques for growing, and also with respect to the particular cannabis strains you prefer to grow.
Hopefully, though, this article is plenty enough to offer you a very solid foundation on which you can get started with your own cannabis crops.
Do, by all means, drop a comment below and let me know how you get on with your own cannabis growing project.