How to grow marijuana indoors

There are many advantages of growing marijuana indoors over outdoors. The main advantage of growing indoors is that you are in control of what you are growing and this tends to result in a better quality end product.

If your new with growing cannabis indoors understand that it presents a unique set of challenges and a lot of information on this subject which can be overwhelming. This guide will help beginners getting started.

Before you begin there are several things you need to take care of.

How to grow marijuana indoors

What do you need?

  • Grow place
  • Light
  • Ventilation / Air
  • Pots and soil
  • Marijuana seeds
  • Nutrients and water
Step by step we will explain how to get started.

Step 1: Pick your cannabis grow place

First step is to choose your indoor growing space. It's important that the space you choose should be enclosed to give you more control over the environment your marijuana plants will be growing in. It can be in your closet, spare room, garage, grow tent or basement. We recommend getting a grow tent in the size that you want and start small if you do this for the first-time.
Also consider the equipment and the temperature of your grow space and keep in mind that your temperature will likely rise once you have your grow lights running.

Step 2: Proper Light

Step 2: Proper Light

Cannabis needs lots of light. The better your light, the more you’ll harvest. When growing inside, where there is less natural sunlight, lamps are used to help the growing process. It's the number one factor in the environment for the quality and quantity of your cannabis yields.
Lighting is the most expensive piece of equipment you going to need. There are many types of artificial light and all of them do different things to your plants. The kind of light you buy will depend on the situation you have in your house.

There are 3 types of lamps that are most used:
- HID Lamps
- LED Lamps
- CFL Lamps

Each type of lighting system has its own advantages and disadvantages. We will give you a short explanation of each type.

HID Grow Lights (High Intensity Discharge)

This class of grow lights includes High Pressure Sodium (HPS) and Metal Halide (MH) grow lights.
High pressure sodium (HPS) produces light that is more on the red-orange end of the spectrum and can be used for the entire grow cycle, but are often used during the flowering stage.
Metal halide (MH) produces light that is blue-ish white and is perfect for the vegetative stage. HID lights are less expensive to purchase than full spectrum LEDs. It gives you a big harvest but uses heaps of electricity.

LED Grow Lighting

LED stands for Light Emitting Diode. LED grow lighting runs at a very low heat, meaning you can grow your plants right up to the light without overly worrying about heat burn. The main drawback to use LED grow lights is that they are expensive comparable to HID. The cost can be 10 times more. Benefits are that it has a much longer lifecycle, uses less electricity and creates less heat.

CFL Lights

Compact fluorescent lights or CFLs are similar to standard fluorescent tubes, but are smaller in size and boast increased power. They're cheap and easy to get a hold of, though they lack the power of dedicated grow lights.

Choose your lightning depending on budget and space.

Step 3: Air Circulation and Temperature

Marijuana Air Circulation and Temperature

Cannabis needs fresh air so it gets the CO2 it needs to grow properly. You will need a steady stream of air flowing through your grow space. You can use a vent and fan to create airflow. If proper ventilation is not maintained, the pores of the leaves will become clogged and the leaves will die.
In a small closet where there are only a few plants you can probably create enough air circulation just by opening the door to look at them.

The comfortable range temperature for the light hours is 70 to 85 degrees Fahrenheit (20-30°C) and for the dark hours there should be about a 15 degree drop in temperature (18-26°C). You’ll need to ensure that temperatures remain within these ranges for your plants to properly grow. Make sure to always check the temperature as experienced by your plants. Check the temperature directly under the light where the top of your plants are located.

Step 4: Setup your timers and monitoring

Step 4: Setup your timers and monitoring

Once selected your grow place, lights and air ventilation for the right temperature, you'll want to setup the right automatic timing cycle for light and dark. You need your lights to turn on and off at the same times every day or you risk stressing your plants, so a timer is essential.
A "vacation" timer, normally used to make it look like you are home while you are away, works nicely and can be found at most hardware or discount stores.

In vegetative stage you will have your lights on for 16-20 hours per 24 hour period. Switch to 12 hours of light per 24 when you want them to bloom, the flowering stage. Generally speaking, the less dark per day the better during the first six months of the plant's life.

You can use a timer for your exhaust fan as well, but a thermostat switch is a much better option. Simply set the thermostat on the device to your maximum desired temperature. It saves you a lot of energy and gives you a steady temperature.

Step 5: Choose your pots and soil

Step 5: Choose your pots and soil

For the growing medium there are many options available to choose from. Each growing medium that you can use has different care and watering requirements. The key is to choose a soil or medium that is airy enough for oxygen to reach the roots. We will give you a short explanation of the two most popular methods.


The easiest growing experience is to grow in organic composted soil. Growing cannabis in soil is similar to growing plants. You can simply buy soil online or at a store. Growing in soil is not as fast as growing in a soilless or hydroponic setup but very easy. You just need soil and a container.

Soilless (Hydropnics)

Another growing medium is hydroponics (also growing in a soilless medium like coco coir). Cannabis roots grow directly in water and/or the grower needs to maintain a water reservoir. This technique leads to faster growth and bigger yields than soil. It also requires a higher order of precision as plants are quicker to react to over or underfeeding and are more susceptible to nutrient burn and lockout.

The solid choice for beginners is always an organic potting soil. The type of container you use will depend on the medium, the system, and the size of your plants. You can buy a breathable pot of some sort. Fabric pots are good and work better than solid plastic pots. Because oxygen can reach the roots and excess water can drain.

Step 6: Pick your cannabis strain

Step 6: Pick your cannabis strain

To get started, make sure you know the difference between Sativa and Indica strains. There is large selection of cannabis strains to choose from. Check out our strain information section to help you make the right decision.

If it is your first time we recommend to choose auto-flowering feminized cannabis seeds. The advantage is that you don’t have to worry so much about sexing your plants because they are chemically treated so that they grow to become females.

Many cannabis collectives and dispensaries will happily sell you clones or seeds. Always buy from a trusted source so you know you can trust the genetics you are receiving.

Step 7: Nutrients and water

Step 7: Nutrients and water

During your grow it is important to plan to use nutrients or fertilizer to make sure your plants are getting everything they need. Marijuana requires the same nutrients as other plants: nitrogen (N), phosphorus (P), potassium (K) and a variety of trace nutrients. A good thing to keep in mind with nutrients and cannabis plants is to always start off slow and don't add too many nutrients. If you do, your plants will end up burning. Better to underfeed than to overfeed your plants.

Most commercial soil will have enough nutrients in it to sustain the plant for about three weeks of growth so you don't need to worry about feeding your plant until the end of the third week.

Plants will not grow without water and watering your marijuana plants properly is essential to any grow. Water is used as a medium to transport the necessary nutrients it needs to live. Cannabis plants are very susceptible to fungal root diseases when conditions are too wet, and overwatering is one of the most common mistakes made by the beginning grower. How often you water your plants will depend on the medium used, size of the plants, and ambient temperature. The smaller the container, the more frequently you will need to water the plant.

You want the water you’re using to have a pH as close to neutral (pH 7). Be careful not to use water with added chemicals. Also make sure the water is not to hot or cold, room temperature is the best.