Rob Hoffman is an English and Spanish speaking writer, documentary…
Welcome to the Guide to Growing Weed Indoors for Beginners. Despite what many believe, growing cannabis isn’t difficult. Technically speaking, one could drop a cannabis seed in their garden in the spring, and without doing anything else, that plant could be ready for harvest by autumn.
But like anything in this world, the more you put into the cannabis growing process, the more you will ultimately get out of it. If your goal isn’t just to grow a cannabis plant, but to actually yield a high quantity of colourful, fragrant, and potent cannabis flower for consumption, that’s when things get a bit more complicated.
The best homegrown plants are cultivated indoors, where you can more precisely control factors like light cycles and strength, temperature, and prevent pests from invading your plant. While being slightly more challenging than growing outdoors, cultivating a healthy, high-yielding indoor cannabis plant can easily be accomplished by anyone who follows the right steps.
That’s why we’ve created this definitive guide to growing weed indoors for beginners. Just like following a recipe, if you follow these instructions closely, you will end up with a cannabis plant you’re proud of.
Step 1 for Growing Weed Indoors: Germinate Seeds
Germination is the process of making your seed sprout into a plant. It’s a quick and easy undertaking that normally requires roughly two-to-seven days to accomplish. There are three main methods that growers typically use to germinate their seeds: the paper towel method, the pre-soak method, and the direct soil method.
Below, we’re going to give you a quick summary of all three methods. While every grower has their own preferences, our recommended method is the “paper towel method.”
Paper Towel Method
The paper towel method is extremely popular amongst professional growers due to its simplicity, and low margin for error. While it may take slightly longer than the pre-soak method, we believe it’s worth the extra time. That’s because the paper towel method, compared to the pre-soak method, poses less of a risk that your seed will experience issues, like rotting.
The paper towel method is extremely simple. All you need to do is place a seed on a thoroughly moistened paper towel, fold the moist paper towel over the seed, then place it in a plastic sandwich bag. Zip the plastic bag shut, and place it in a dark and warm place (such as a dresser drawer). Every morning and night, take a quick look to see if a root has sprouted. Once the root appears, that means your seed is germinating and it’s time to transfer it into your growing medium.
The pre-soak method simply means submerging your seed in warm water. Simply pour warm water into a glass, and drop the seed in. Make sure the water isn’t too hot. By completely soaking your seed in water, you will hopefully be able to speed up the germination process. This also ensures that your seed is thoroughly moistened before it’s planted in your growing medium.
Once you see that a root has started poking its way out of your seed, it’s time to transfer your seed into a growing medium. However, this can be a risky method as it may lead to seed rot or mold, which obviously isn’t the ideal way to begin your cannabis growing journey.
Direct Soil Method
This is the most simple seed germination method of all. For the direct soil method, simply make a little hole in the top of your growing medium, and drop the seed in. Some growers may moisten their seed before placing it into the growing medium, while others will just place it in dry. Either way, make sure that the pointed end of your seed is facing down towards the base of your growing medium.
Once your seed is sitting snug in the little hole you’ve created, cover it with a thin layer of growing medium. Then, moisten the medium by lightly spraying or pouring a small amount of water onto it.
If your seed was dry when you placed it into your growing medium, cover your growing container with plastic wrap. This will create a greenhouse effect.
Place your container of grow-medium (with the seed inside) in a dark, warm place. Every day, take a look to see if a sprout is breaking through the thin layer of growing medium that’s covering the seed. This will normally take about four to five days. At this point, it’s time to move your seeds into your grow room, where there will be light and proper ventilation. Now for stage two of the Guide to Growing Weed Indoors for Beginners
Step 2: Vegetative Phase
The vegetative phase spans from when your plant is still only a seedling a few inches tall, all the way to when it looks like a full grown bush. While your plant is still a seedling, you will want to expose it to higher levels of humidity. The easiest way to achieve this is by putting a humidity dome over the seedlings. Keep the humidity in this dome between 70% and 90%. Slowly wean your seedlings off of humidity by removing the humidity dome in stages over the course of about two weeks.
Fluorescent lighting is typically used for the seedling portion of your vegetative phase. You want to keep your seedling in a growing medium (soil, clay balls, perlite, etc.) that is damp, but not wet. The water you feed your seedling should have a PH level of 5.8 to 6.2.
Once your seedling’s roots start poking out of the medium you grew them in—a sign that they’re in need of more room to spread out—move your seedling to a larger medium. Like the transition from adolescence to adulthood, this is the stage when your seedling starts to become a plant.
Increasing Your Lighting
Once you move your plant into a larger growing medium, it’s time to increase your lighting. Many growers will take this opportunity to put their plants under a stronger light, by either increasing the fluorescence, switching to strong LED lights or using HID lights (which are popular with experienced growers).
This new growing medium and lighting set-up is where your plants will spend the remainder of their lives. Technically, you could keep your plant in the vegetative phase forever, allowing it to grow bigger, and bigger, and bigger still.
This part of the vegetative phase is when you’ll want to do any topping or training to your plant in order to create an even canopy so that all of your plant’s colas are receiving as much light as possible. Any part of your plant that’s not getting sufficient light will not produce much flower when it’s time to move into the flowering phase. Creating an even canopy will increase your yield.
The Key to This Phase
The key to this phase is exposing your plants to more than 12 hours of light per day. Any shorter and you’ll force your cannabis plants into the flowering phase. Some growers keep their plants under light for a full 24 hours a day during vegetation. Other growers claim that this doesn’t allow your plant to “rest,” as they do in nature when the sun goes down, and prefer to do daily 18-hour light/6 hour dark cycles. (Pro tip: choose off-peak hours to run your lights to keep electricity costs down).
Humidity and temperature is also important for this phase, so head to your local drug store and purchase a thermometer and hygrometer, or an indoor humidity monitor. Then, make sure that the room where your plants are located maintains a humidity level of about 40 to 70 percent. Make sure the room’s temperature stays between 22 and 28 percent.
Nutrients Guide to Growing Weed Indoors for Beginners:
If you add too many nutrients too soon, you’ll essentially kill your plants with too much love. It’s called “nutrient burn” or “nutrient shock.” Think about it like this: if you were trying to run a marathon, you would work your way up to 26.2 miles—you wouldn’t try to run that on your first go.
Pay close attention to the brand of nutrients you buy. Like laundry detergent, some nutrients companies dilute their ingredients, while others are more concentrated. For this reason, the amount of nutrients you need to feed your plants will depend on the brand of nutrients you buy.
In order to make your plants happy, simply follow the nutrients chart of whichever nutrients company you choose (call your local hydroponics store, and go on the website of whichever brand of nutrients you buy. There you will find a nutrients chart.) In some cases, you will find this information directly on the packaging.
Step 3: Flowering Phase
This is often the most exciting phase of growing weed indoors since it’s when you’ll start to see flowers forming on your cannabis plant. The key to this phase is giving your plants exactly 12 hours of light and 12 hours of darkness per day. Most people set their lights up on an automatic timer to maintain this strict light cycle.
For this phase, you will also want to lower the humidity in your grow room, or else you’ll get bud rot, bud mold, and all sorts of other issues. The easiest way to do this is to increase your airflow (turn your fans up) and decrease your temperature to between 20°C and 26°C. Be careful: if the temperature in your room gets lower than 20°C your plants might drop dead.
See Also: Best Temperature and Humidity
You will know that you’re entering the final weeks of flowering when you see developed buds with trichomes that are beginning to look cloudy. You can observe the plant’s trichomes with a special microscope, which you can purchase for $10 – $20.
During these final two weeks of flowering, lower your room’s humidity another 10 percent to improve your flower’s flavour and appearance. The idea here is to replicate what happens in nature. At the end of the summer, as you move into autumn (the harvesting season in North America) you typically begin to get chillier nights and lower temperatures.
During the final one to two weeks of the flowering phase, you will want to flush your plant of all its nutrients. Don’t feed your plants any nutrients for these final weeks, only clean PH balanced water.
Step 4: Drying/Curing Your Flower
It’s best to dry your cannabis flower in a dark, cool place with low levels of humidity. Specifically, your room’s humidity should be somewhere between 30 to 50 percent. A lot of growers dry their flower by hanging it upside down. You’ll want to hang your plants for about a week, with adequate but not direct airflow.
Some growers prefer to trim their buds before hanging it to dry so that they dry faster. Whether you trim your bud before or after you dry it, make sure you save your trimmings. These trimmings can be used to make other great cannabis products like wax, or edibles. Take a look at our comprehensive guide to learn how to make wax from your trim.
You will know your flower is dry when the thin stems begin to snap easily, rather than bending. Your thicker stems will likely never be snappable, but they should be crunchier and less flexible.
When your flower is sufficiently dry, it’s time to put it in jars to begin the curing process.
Put your cannabis flower in mason jars with humidity packs. Every day, you will want to “burp” the jar by opening it for a few seconds to allow the flower to breathe for a moment.
Wait a minimum of two weeks before smoking this flower. (If you’re desperate, you could technically dry this flower in the oven and smoke it immediately, but it will be far from optimal.)
Thank you for reading this Growing Weed Indoors for Beginners. It is highly unlikely that you are now a professional, so you should probably will need to do a little more reading. We have a lot more guides that we recommend reading before you begin your own grow.
Rob Hoffman is an English and Spanish speaking writer, documentary filmmaker, and SEO specialist. Rob’s work has appeared in a number of major publications like Politico, ThinkProgress, Fusion, Herb, and DoubleBlind.