If you’re looking for the basics for your first indoor marijuana grow, here are the tools and information you need on how to do it effectively. All you need is a small, discreet space and a little budget to get started with indoor cannabis production.
Growing marijuana indoors is a fascinating and enriching experience because, although it requires more resources than growing outside, you have total control over all the parameters the plants need to develop.
You can also regulate the length of the growing and flowering periods, which allows you to harvest several crops at any time of the year, obtaining consistent yields at all times. Also your crop will be hidden from neighbours, curious or possible thieves, as the plants grow discreetly in an enclosed space.
So, here is a list of general things to consider and the basic equipment needed to start growing marijuana indoors.
Cannabis plants can be male or female (or hermaphrodite). Female plants produce female flowers or “buds” and, to produce seeds, they need to be pollinated by a male plant.
When females are deprived of pollen from males, they produce larger, thicker, seedless buds. These inflorescences (clusters of small flowers) contain the highest concentration of cannabinoids in the plant.
Growing regular cannabis seeds can produce either male or female plants. But many growers buy feminized cannabis seeds to ensure that they will only get female plants, which avoids wasting time and effort waiting for a regular plant to show its sex.
Cannabis is an annual plant, its flowering period is determined by the seasons and when the cycle ends, the plant dies. Therefore, its development is subject to the photoperiod, that is to say, to the changes in the duration of the light and dark periods.
Outdoors, cannabis plants sprout in spring and grow until summer, when they begin to flower as the days begin to shorten. As autumn approaches, they stop growing and develop fat, resinous buds in an attempt to get the most successful pollination.
To replicate this process indoors, growers artificially shorten the light period from usually 18 hours of light and 6 hours of darkness (18/6) to 12 hours of light and 12 hours of darkness (12/12). If the plant continues to live under an 18/6 hour light regime, it will remain in the vegetative stage and will not begin to flower.
This is where another type of seed comes into play: Autoflowering seeds, which produce female plants that do not need photoperiodic conditions to change from the vegetative stage to the flowering stage. They are designed to start flowering within a certain period of time, despite environmental conditions and light stimuli.
But before germinating the seed, the first thing you’ll need is a place to grow your plants. You don’t need a particularly large space: a grow closet, a small room or even a designated area in a spare room will suffice.
It’s a good idea to start small, because the smaller the grow, the less expensive it is to set up and the easier mistakes will be to fix.
You will also need an exhaust fan, air conditioning units or an activated carbon filter to renew the air, reduce heat and eliminate odours. A fan will keep the air moving and prevent stagnation. A thermometer/hygrometer is also a must, as well as a pH meter.
One of the most important elements of any crop is artificial lighting. HID (high intensity discharge) lighting fixtures such as HPS (high pressure sodium), MH (metal halide) systems with ballasts, or CMH (cermanic metal halide) are the traditional standard. If heat from these lights is a problem, there are also LED (light emitting diode) and CFL (compact fluorescent) systems.
Make sure you get a light that covers the growing space and at a height that can be adjusted to suit the different stages; and invest in a decent timer to control when the light turns on and off.
During the vegetative stage, the plant will grow leaves and branches, but no flowers. When you’re ready to start the flowering stage, switch to a 12/12 light cycle. Be sure never to interrupt the dark period with light – interruption or irregularity in the dark period can have negative consequences on the plants, including trigger hermaphroditic expression. In the latter case it is important to detect the early signs of hermie plant.
A common assumption among beginners is that the more you water, the better. But watering frequency and amount are determined by some obvious things, such as the size of the plant or its stage of development, as well as the size of the container its in. Temperature and humidity of the air around the plants is also a key determining factor.
There is a science to watering cannabis, however each cultivator must learn how to determine watering needs based on their individual factors and conditions.
Marijuana roots prefer a wet/dry cycle for growth; this functionally means that they like to be well saturated with water and then let to dry out a bit before being well saturated with water again.
Because water is heavy, you can lift with your hand and gain an idea of how much water is left in the soil at any given moment. A common mistake for novice growers is to water too frequently with too much water, functionally drowning the roots.
Remember that the roots need lots of oxygen and that good drainage is important.
Whenever space is limited, every inch should be maximized. This means choosing between growing Indica-dominant strains, which are more compact, or planning to use pruning and trellising techniques if growing Sativas, which tend to stretch more.
It will also be essential to choose the right growing medium, which is the one that provides physical support for the plant, allows the roots to breathe and retains available water or nutrients for stable, healthy growth.
As mentioned before, good capacity to drain is very important. When using soil, many cultivators will amend their soil with copious amounts of perlite or hydroton in order to improve and facility drainage and to ensure plenty of soil aeration
Soil is the most traditional medium for growing marijuana indoors, as well as the most forgiving. Be sure to choose soils that not only have good ability to drain, and aerate, but also contain the nutrients necessary for healthy growth. Some cultivators choose to work with living soils, while others prefer to maintain their plants through soluble salt fertilizer solutions.
Growing cannabis without soil is also possible and is one of the most productive methods, but requires a greater investment of time and money. It is called hydroponics and the roots of the plants are exposed to a nutrient-infused and air infused water solution.
Often these systems rely on this solution running over an inert medium such as perlite, clay pebbles or rockwool, and other systems leave the roots suspend in air or water without a non soil substrate.
In addition to these aspects, a number of important parameters must be monitored for a successful crop:
These are two critical factors, so you’ll want to make sure they stay within a comfortable range for your plants. For the most part, marijuana prefers these temperatures when the lights are on:
As a general rule, the temperature difference between the light and dark periods should not exceed 10 °C to avoid stressing the plant.
Remember that for temperature, maintaining stables temperatures is often more important than if temperatures are a little bit too warm, or a little bit too cold.
If you are growing in soil, you won’t need to add nutrients every time you water (unless you are using a hydroponic medium): you can use a standard soil mix and then supplement with liquid nutrients, which come in formulations for vegetative or flowering periods.
Before watering, check the pH of the water to control its acidity. If you are growing in soil, try to keep the pH between 6 and 7, with a sweet spot between 6.2 and 6.5.
If you are growing hydroponically, 5.5 to 6.5 is an appropriate range with the optimum point being 5.8 to 6.0.
Overfeeding plants should be avoided at all costs, as it is always easier to add more nutrients than to remove them. The first sign of overfed plants is burned and curved, claw-like leaf tips.
Plants require cool air to thrive, so you’ll need a constant current flowing through the grow room. This is accomplished by placing an extractor fan at the top of the space to suck out warm air and an extractor fan on the opposite side near the floor to bring in cool air.
It is also a good idea to have oscillating fans to provide a constant breeze, as it will strengthen the stems of the plants, making them stronger and healthier.
Proper air circulation will help maintain temperature and humidity; and it will also reduce odour by exhausting it out of the room through an activated charcoal filter (recommended), avoiding odour problems for neighbours.
CO2 is an essential element for the photosynthesis process. Therefore, if the level of CO2 in the air is increased, the metabolization processes will be accelerated, which will result in higher yields.
However, the use of this type of technique is not within the reach of everyone. Therefore, in order to introduce a CO2 supply system in the crop, it is necessary to have an advanced level.
CO2 enrichment requires increasing temperatures, nutrient availability, and lighting intensity in order to see its benefits.
Finally, what are the 5 essential tips that every beginner grower should know:
Growing marijuana indoors is a wonderful experience. You learn a lot about cannabis botany and it is also an excellent process of personal growth.
There is no doubt that there is a bit of a learning curve, so you will make your fair share of mistakes in the beginning. However, trust us when we say that, in the end, your efforts will be worth it.
Remember that Autoflowering cannabis can be the best option for beginner growers, because they don’t have to worry about guessing if the plant is male or female or when to change the photoperiod. This makes their cultivation a faster and easier task.