Updated: Apr 21
Since the dawn of legalization, Canadians have been showing more and more interest in growing cannabis at home. The benefit of growing at home as opposed to purchasing flower from a dispensary is that you actually know exactly what is going into or onto your plant, and you end up spending less money in the long run.
On top of being cheaper, organically grown cannabis will spare your body from the harmful chemicals typically used on commercially grown cannabis. There will be no pesticides, fungicides, chemical fertilizers or synthetic nutrient supplements used on your own organic crop. If you’re growing for medicinal purposes, you should consider growing organically to remove the chance of ingesting chemicals that could be in your medication.
Here we will provide a beginner’s breakdown on the 4 things you will need to start growing organic cannabis indoors:
Space seems like an obvious consideration, but the quality of your space will have a significant impact on your growing experience. Assuming that you will be growing in your own home, you will need to allocate one room or area in your house as the grow site. This should be a rather inconspicuous area as you want to be able to control who can access or see the space.
Closets, a basement, or an attic all provide an out-of-the-way space for a grow site and should offer plenty of room to let your plants grow. It would be worth considering a grow tent for your space. A grow tent will come fully equipped with lighting, ventilation, nutrient and water supply AND will likely fit in your closet. The cheaper grow tents will cost between $50 and $100, but the accessories will increase that bill to around $250.
Your plants will need to follow a strict lighting schedule if you want them to perform well. There are two main choices for lighting:
HID (High Intensity Discharge)
LED (Low Emitting Diode)
HID lights have been the long-time standard for growers. They are known to create huge yields if used correctly. HID lights are also notoriously hot, and must be kept further away from plants. These bulbs use significantly more energy than LED lights.
LED lights are energy efficient alternative that provides significant luminosity while using much less electricity. Many commercial growers are switching to LED for the power saving benefits and heat efficiency. LED lights also produce a broader spectrum of light and do not require a bulb change to switch light spectrums.
In essence, HID bulbs are cheaper upfront but will use significantly more electricity which will increase your costs in the long run. LED bulbs are more expensive upfront but will use much less electricity, saving you money in the long run.
Cannabis plants needs fresh air to survive and carbon dioxide for photosynthesis. Your grow site will need to include a way to introduce fresh air to your plants, and remove warm air from the site. This could be an easy or hard task depending on how your grow site is set up. A general ventilation set up would include:
an exhaust fan near the top of the site to remove warm air
a filtered inlet on the floor to pull in fresh air.
Most grow tents will have included cut-outs or attachments for ventilation, another reason to consider purchasing one.
It’s imperative to know that to grow organic cannabis in Canada, you must grow your plants in soil. Canada does not recognize hydroponically or aeroponically grown plants as organic. You will need pots for your cannabis plants to reside in. A standard garden pot will work, or you can search the market for grow pots which often allow the plant to grow using both soil and a hydroponic base. Any organic potting mix from your local garden centre will do for a starter soil.
Your goal with organic fertilizers will be to feed the soil, not the plant. Organic soil will already have beneficial microbes present, but they will need to be fed. Adding compost or other organic material will give the microbes a source of food to decompose which will release nutrients to the soil. Some microorganisms will even fix nitrogen from the air, or solubilize micronutrients like zinc. Nurture Growth biofertilizer can provide your plants with a proprietary blend of beneficial microorganisms, fixing and solubilizing just about every nutrient your plant will need AND it’s certified organic.
Cannabis will require different nutrients at different stages of growth. In vegetative stage, the plant will want more nitrogen to grow tall. In flowering stage, the plant will want more phosphorus and potassium to sustain growth and produce buds.
Watering cannabis plants isn’t an exact science, it depends on the size of your plant and soil drainage. Balancing water retention and drainage is critical. Start your smaller plants (seedlings) in smaller pots to reduce the risk of overwatering. Check soil moisture daily, but they should be getting water about every 2-3 days. As the plants increase in size during vegetative stage, transfer them to bigger pots and give them more water more frequently, almost every day.
Stages of Growth
Cannabis plants go through several stages of growth before reaching peak bud production. Each stage will have different light, water, and nutrient requirements.
Seed (2-5 Days)
Start your grow by purchasing feminized seeds from a reputable vendor. The seeds will need to be germinated before they can be planted. Germinate your seeds by placing them in a damp, folded up piece of paper towel. Keep them in the dark for 2-5 days and at room temperature, and their roots should have sprouted enough to place them in a small pot.
Germination (5-10 Days)
Once the seed has popped and the root has emerged, its time to plant your seed in soil. Very carefully remove the sprouted seed form the paper towel and place it about an inch deep in your potting container.
Once planted, you will notice rounded leaves growing out from the stem. These leaves are crucial for taking in the light needed for further growth. At this stage, you should be providing your plants with 18 hours of light and 6 hours of darkness.
Seedling (2-3 Weeks)
When the first set of iconic fan leaves emerge on your plant, it will officially be considered a seedling. New sprouts will produce leaves with only a single ridged blade. As new growth emerges, plants will develop leaves with 3-7 blades. A seedling will transition into vegetative stage once new growth leaves have 5-7 blades.
Healthy seedlings should be a bright, vibrant green colour. Be careful not to overwater plants during this stage. The roots will still be quite small at this point and do not need a lot of water to thrive. If kept too saturated, the plant will be vulnerable to disease and mold. At this stage, the plant should be receiving 18 hours of light and 6 hours of darkness as well as weekly NGBIO or organic fertilizer treatments.
Vegetative (3-16 Weeks)
This is the stage where you will see the most dramatic plant growth. At this point, you should begin to transplant your plants into bigger pots to account for new root growth. You should be seeing new growth on your plant almost every day.
During this stage you can begin to “train” your plant. If left untouched, the cannabis plants will grow straight upward like a christmas tree and form one major bud on the top of the plant. Having one big bud reduces yield from the rest of the buds on the plant and having a christmas tree shape will prevent light from penetrating the bottom dwelling buds. By bending your tree at the top, just enough to kink the steam but not tear it, you can encourage horizontal growth and an even distribution of buds.
The cannabis plants will require much more water at this stage, almost a litre per plant per week. It’s recommended to water further away from the stem of the plant each week to encourage the roots to spread farther to find resources, which will strengthen the plant’s foundation. The plants will require 18 hours of light and 6 hours of darkness at this stage.
Flowering (8-11 Weeks)
The final stage of plant growth. This stage is induced by the grower when they switch the light cycle from 18 hours on, 6 hours off to 12 hours on, 12 hours off. This replicates the natural light cycle the cannabis plant would experience in nature, transitioning from summer to fall and receiving less light as the days get shorter. The lighting switch triggers the production of heavy, resinous buds, and the fruits of your labour will finally be visible.
Sex can be determined during the early flowering stage. You will want to remove any male plants as they can pollinate the females and reduce the potency of their buds. Pollinated females spend more energy producing seed than developing buds, which is not what you want.
Some growers don’t like to fertilize at this stage to prevent any excess from getting onto the buds. Using a certified organic biofertilizer like Nurture Growth Biofertilizer will add a healthy microbial population to your soil which will fix and solubilize the nutrients that the plant needs. Furthermore, don’t prune your plants after 3 weeks into the flowering stage or your risk upsetting the hormone balance in the plant.
Determining the perfect harvest time is difficult. Most plants will be ready for harvest after about 3-4 months. The recommended way to determine harvest date is to purchase a hand loupe or handheld microscope, and look at the cloudiness of the trichomes (little white fungal shaped hairs) on the buds. Perfectly clear trichomes are not ready for harvest, cloudy trichomes are at peak THC content and are ready for harvest. Trichomes that are an amber colour have gone past the ideal point of harvest, and the THC present in them is degrading into CBN (cannabinol), which provides a more couch-locked and relaxed sensation.
With these tips, you should be able to get started on planning your first indoor organic cannabis grow at home. You likely won’t produce a High Times Award Winning batch on your first go, but you can certainly have a blast growing at home and enjoying your own harvest. Remember to grow safely and keep your grow site inaccessible by children!
P.S. The timelines provided with the stages of growth are just an estimate, please refer to the plant growth schedule that should be provided by your seed vendor, or simply google the plant care requirements for the specific strain.
If you have any more questions about the study or just need some gardening advice, feel free to write to us on email@example.com. Join us for our end-of-the-month webinar series for home gardeners to learn more about new trends and gardening tips!
Eric is a gradate of the Environmental Science program at the University of Toronto. Coming from the green roof and landscaping industries, he does not hesitate to get his hands in the soil. He is actively searching for new ways to learn about our agricultural systems and get involved with his local agricultural community. Eric is an avid birdwatcher and advocate for environmental responsibility.