Cannabis can be grown indoors in a soil-like medium under artificial light, adding fertilizer when the plants are given water. Cultivating cannabis indoors is more complicated and expensive than growing outdoors, but it allows the cultivator complete control over the growing environment. Plants of any type can be grown faster indoors than out due to 24-hour light, additional atmospheric CO2, and controlled humidity which allows freer CO2 respiration.
Plants can also be grown indoors through the use of hydroponics.
To grow plants indoors, a growing medium (e.g. soil or growing substrate), water, nutrients, light and air need to be supplied to the plant (with the exception of aeroponic cultivation, in which case a growing medium is not required)