Growing Marijuana Indoors
This is a simple starting guide on how to grow marijuana indoors. As growers become more experienced, so will the techniques used. To start with, try and keep it simple.
To start with, you will need some marijuana seeds. The type of seeds used for indoor cultivation are often different to those used for outdoor growing. Breeders have optimised characteristics for the indoor enviornment. For help choosing the right strain, consult our marijuana strain selection guide as well as our cannabis cup winners section. Note clones can also be used.
Once you have your seeds or clones you need to choose an area to grow. This can be a closet (wardrobe), an attic, or a sectioned off part of a room, a whole room or a basement. It is important to plan this step well as the results will reflect your planning. The more you do the higher quality and less problems will follow.
The wall of the space should be painted flat white (this reflects light the best). Better still get some panda film or Mylar (these are both sheets of plastic, black on one side and silver or white on the other). Not only do these give you excellent control, but reflect much better. You can affix the rolls of panda/mylar with PVC (duct tape). Do not use mirrors, they reflect light poorly.
The indoor grow room should be well vented ideally with an extraction fan (the bigger the room the more powerful this needs to be). This is often cut into the roof if possible like a regular bathroom fan. Air also needs to circulate freely throughout the room or space, usually a regular oscillating fan will work fine, just make sure it's not blowing the plants around too much as this will stress them. Venting the marijuana grow room is very important as the lights will put out alot of heat.
First you will need to germinate seeds, see the germinating marijuana seeds page for more information on this.
Choosing containers for growing
Many indoor marijuana growers will use regular garden pots for growing, though just about any plastic or even metal container can be used. If using regular soil make sure there is a layer of drainage at the bottom of the pot i.e. gravel. It is important to obtain high quality soil, don't just dig it from your garden. The size of the pot will determine how big the plant can get, use around 1-6 gallon containers as a general rule.
For better results many growers will grow hydroponic marijuana, this technique does not usually use soil but another medium i.e. perlite, rock wool or vermiculite.
Hydroponic marijuana is grown using several pots connected to a reservoir. The reservoir has a pump connected to a timer. Each pot is watered on regular intervals throughout the day with a nutrient mix, see marijuana nutrients.
Photos of hydroponics systems here
If using regular soil nutrients are added to maximise the growth potential , It is very important that plants are not over fertalised, This is one of the most common mistakes when as a buginner growing marijuana indoor.
All plants need light and there is no sun indoors. The light provided by the sun needs to be replaced with an artificial light source.
Incandescent lights, like regular light bulbs, simply won't cut the mustard, they put out light in the wrong spectrum and are too costly to run. You can find a detailed guide to marijuana lights on our marijuana lighting page.
In simple terms there are 3 types of lights available; Fluorescent lights, Metal Halides (MH) and High Pressure Sodium (HPS) lights. Fluorescents can be used effectively in the cloning and seedling phases, though are not as effective as MH and HPS lights through the rest of the process.
MH work extremely well in the vegetative period (i.e. before the plant begins to bud). HPS lamps are the best solution in the flowering (budding phase). The ideal combination would be therefore MH through vegetative, swapping or supplemented by a HPS in flowering. Saying that, either metal halide or HPS can be used effectively on their own.
The growing cycle is also controlled by light. This is one of the main advantages of growing marijuana indoors. Initially in the grow period (vegetative), lights are kept on for approximately 18 hours a day. When you want the plants to begin flowering the light is restricted to 12 hours light (and 12 hours dark). Turning back the lights as it is referred to, induces the plants to bud. Flowering usually lasts for 8-12 weeks and then the plants are ready for harvest.
Once the plant begins to bud it is time to look for the males and weed them out. A magnifying glass is the best way to do this early. More information about male and female plants can be found here.
The ideal temperature to grow marijuana is around 75 degrees F or 24 degrees C. Plants though can survive from around 40 degrees F (5 degress C) to 100 degrees F (38 degrees C). Humidity in the grow room should be kept between 60- 80%. Above 85 % and the risk of mould is greatly increased.
Harvesting marijuana is often best done by keeping a close eye on the plant. More information about when the best time for harvest is can be found on our marijuana harvest page.
There are many recommended methods for drying marijuana. A simple way is to simply hang up the harvested plants in a well ventilated room that is not too hot or cold. More drying information can be found on the marijuana drying page.
Growing marijuana indoors can be a fun and interesting process. The more effort that goes into managing the garden, the better will be the result. A good book can also help if problems such as pests occur. A wide range is available at Amazon.