The Basics of Indoor Cannabis Cultivation
Guest post by Se?or Wavy
Cannabis is a very versatile plant that can be grown in a number of places.
Especially with new advancements, such as auto-flower seeds which don’t require any specific amount of light to flower and tend to be vigorous, strong cannabis plants. (JustCannabisSeed.com has quite a few great auto seeds, I personally have tried the Sour 60 Autos and loved them)
In my personal opinion, growing cannabis outdoors is obviously the most ideal situation, however, there are many climates and situations where some folks are unable to do this all year, or at all. In these places especially it is very useful to be able to grow indoors.
There are other benefits to growing cannabis as well, such as being able to utilize hydroponic systems, protection from environmental changes and people (thieves), and perhaps most notably, being able to fully control the flowering schedule, and grow any time of the year.
So, in this article, we will be going over some of the basics to consider when growing indoors.
First things first…
Pick Your Cannabis Seeds
A journey of a thousand miles begins with a single step, and in this case a single seed.
The seeds you choose to grow will determine the genetics of the plant. Plant genetics determines many things, including what environment it prefers, unique aspects of caring for it, size and shape of the leaves and the cannabis plant itself, as well as effects of the final product…..the flowers.
Historically, Indica strains have most popularly been grown indoors due to their shorter stature and quicker flowering time than Sativas.
This is no longer always the case though, as years of breeding and crossing strains has led to countless hybrids, many of which can display either Indica, Sativa or mixed characteristics with varying heights and flowering times.
Strains that are genetically pure from their origin are known as landrace strains. There are quite a few really great offers for landrace seeds here on JustCannabisSeed.com as well if you are interested in them.
When growing indoors I would stick to Indica landrace strains or hybrid cannabis strains which allows you to let the plant express its full potential.
Some Sativas may run out of room without some training.
Other factors you will want to consider are potential yield, resistance to cold, heat, pests and diseases, and effect.
Growing indoors gives you the big advantage of being able to keep many common pests out of the grow room.
Growing indoors also means YOU are Mother Nature and have control of humidity, heat, temperature, light, ect. This allows you to choose certain genetics that may not thrive particularly well outdoors.
Depending on the size of your indoor grow space, the main things I would look out for in choosing genetics are:
Size of the finished cannabis plant (Choosing shorter plants if you have limited space)
Flowering time if purchasing photo strains, (If you choose regular (not autos) seeds you will want to keep them in a vegetative growth stage for at least two to four weeks before you initiate flowering.
Finishing times if starting auto-flowering cannabis plants. (There are also auto-flowering cannabis seeds available on this site which will be ready to harvest in about 2 to 3 months regardless of any particular light schedule.)
Smell (This one is more about personal preference. If you have a space where you are comfortable with the smell of your plants drifting out and prefer strong-smelling flowers, then anything you choose will be fine. However, if you are not a fan of very pungent medicine or are around others who are not, then you may wish to choose a strain known for its more mellow aroma, or at least not anything like a skunk or cheese. Carbon air filters can drastically reduce the smell coming out of a grow room or tent, and are used by many growers)
And obviously, Effect (Indicas tend to be more bodily relaxing (hence the term…couch lock, and Sativa’s more cerebrally stimulating, although as mentioned before many hybrid genetics are cultivars of both)
Choose Your Growing Medium
This is probably where growing indoors gives you the most options, when indoors you can choose from any growing medium such as soil, coco coir or rockwool as well as other hydroponic and organic mediums.
There are many subtleties as well as advantages and drawbacks to each one, so I would highly recommend researching further on your own before you decide.
However, as a basic rundown, soil is known to be the most forgiving as the pH does not fluctuate as drastically compared to growing hydroponically, and the soil provides somewhat of a buffer to stresses like nutrient deficiencies or overages. You can buy bagged soil specifically made for cannabis online or in hydroponic or garden stores.
Alternatively, you can look up recipes of how to make your own. This makes the soil a reliable choice, especially if you don’t have access to anything else.
Another very popular option is coco which is shredded coconut husks. This is a hydroponic medium, even though it is sourced organically. Many growers prefer coco coir, especially indoors as it has excellent drainage and aeration for roots, although this ties into it drying out faster than soil as well. There are no nutrients in coco, so you will need to supplement for everything the plant needs.
Another popular choice is DWC (Deep Water Culture) which is when the plants’ roots are entirely suspended in a water and nutrient solution. This method especially deserves an article of its own, so if you are going for this one I would definitely recommend researching it before you begin.
If you go with a medium such as soil or coco you will next need to choose a container.
Many people including myself prefer and have had great experiences with fabric pots, which are essentially cloth or fabric bags designed to keep light out, yet allow maximum airflow to the roots. This helps ensure your plants do do not get overwatered, as well as improves root health by increasing circulation of air, and prunes the roots when they touch the sides, preventing your plant from becoming root-bound.
Aside from these, any normal plant container will work, and if going for bigger plant size and yield, it is recommended to use at least a five or ten-gallon pot. 5-gallon paint buckets are a popular option that you may have laying around.
Choose your nutrient solutions
After deciding on a growing medium and genetics, the next consideration will be nutrients.
Cannabis, like all plants, needs at least nitrogen phosphorus and potassium (NPK) in sufficient and balanced amounts.
Beyond these base nutrients, your cannabis plants will also require calcium, magnesium and sulfur, and a list of micronutrients that includes: Zinc, Iron, Manganese, Molybdenum, Chlorine, Cobalt, Silicon, Boron, and Copper.
If you are choosing to go with bottled or pre-made nutrients then simply follow the directions from the manufacturer.
However many nutrient companies suggest and it is a good idea to start at half, or even 25% strength and see how the plants react. This is because overfeeding your plant can seriously stress it,and it is better to work your way up than need to flush after over-applying.
The other option would be sourcing your nutrients from more organic means such as bat guano, dolomite lime, and making compost teas. This is my personal favorite choice due to the fact that it reduces the risk of nutrient buildup, requires less flushing before harvest, and creates a healthy soil that feeds the plant for you.
It is a common saying and sentiment that you are not feeding the plant, you are feeding the soil/growing medium, and that feeds the plant. For this reason, I and many other growers prefer using super soil or “living soil”. This is simply soil that contains an active number of beneficial bacteria and microbes to produce and break down nutrients and sugars for the plant.
This is quite possibly one of, if not the most important areas to be aware of, and I highly recommend researching this subject in particular further if you are interested in growing cannabis plants.
Pick Your Grow Space
Because this article focuses on growing indoors specifically, you essentially have a few options.
Depending on your situation you may choose to grow simply, in a window with a lot of light, or ramp it up a bit to a closet, a small room or one of the very popular grow tents, or go for it and fill an entire room.
If you are going to prepare a room or closet to grow in, the best reflective material is either mylar or something of that nature, or just plain bright white painted walls.
If you are using a grow tent this will already be taken care of for you, as well as light proofing, which is ensuring no light can enter the growing space during the dark cycle. This is very important as any light leakage or interruptions can potentially stress plants, causing hermaphrodites or abnormal growth.
It is wise to choose a grow room in which you can maintain a steady temperature ideal for growing cannabis, which is around 75 degrees.
Grow tents may be placed in closets or simply wherever in the room you like. Make sure to choose a proper size so that you have enough light for all your plants and enough room for them to reach their fullest potential.
Grow Lights, Fans, and Filters
When it comes to choosing a light, it can be difficult to know where to start.
There are so many options available on the market today including LED’s, HID (High Intensity Discharge) systems and many more. Although HPS lights had been the standard for cannabis growing for years, many new advancements in LED technology has made them high quality, and cost-effective, some comparing to or exceeding HPS (High Pressure Sodium) lights in effect.
With this there is a huge influx of brands and models to choose from. A simple rule of thumb is that you want a minimum of 50 watts per one square foot when using a HID light. Although LEDs may be advertised at a certain wattage, this is actually not the wattage they consume or always put out in regards to how plants use it.
Given this a more effective and realistic way of measuring light energy for plants is known as PAR (Photosynthetic Available Radiation). This is basically the energy that a plant can absorb from a light, and much more accurate and determining if you have enough light for your plants. It is best to look into the particular light you will be using and see what they manufacturer says about the strength, as well as others who have used it.
A good start to finding a light would be to ask any growers you know, or search and ask in forums for any recommendations based off of experience.
Some well known brands include Mars, Spider Farmer, Son T Agro, ViparSpectra, Maxisun, and many, many more.
The next thing to think about is a fan. You will likely need both an exhaust fan for controlling heat, and moisture in your grow space, and a fan for circulating the air within the grow space.
If you are using any type of light that gets significantly hot, such as an HPS (High-Pressure Sodium), you will want to have an exhaust fan venting hot air away from the plants and cold air to cool down the light.
However, if you are using a newer LED or anything of that nature, it is less necessary to focus on cooling down the lights as temperatures usually do not get as extreme.
Common placement for fans includes one blowing near the base of the plants which helps with airflow, as well as discouraging pests or airborne diseases from getting too comfortable. Depending on the size of your space you will probably want at least 2-3 smaller fans for optimum airflow, with one on the floor, one pointing at the plants and one near the ceiling or light.
It is very useful to note that, in general, multiple smaller lights or fans will be more effective than one big light or fan. This is because you can position them more effectively and get maximum light coverage or airflow.
One of the last considerations for growing cannabis indoors is an air filter. This is especially important when growing in enclosed spaces. Most commonly a carbon exhaust is used to vent fumes out of the space and through the carbon thereby neutralizing the smell.
You can research how to set up rooms with air filtration systems, and many grow tents have simple openings you install them in.
At this point, you are ready to grow!
If you follow all of the steps above and properly prepare your space, you should be looking at relatively smooth sailing, and begin to enjoy the wonderful art of growing cannabis. (it really should be considered an art!)
Online forums are a very helpful place to go for advice in general, as well as if you have any specific questions or problems.
As always, have fun enjoying this magical plant, and happy growing!