Different Indoor Marijuana Growing Medium

Indoor Marijuana MediumYou have soil as the main growing medium option if you will cultivate marijuana outdoors but if you decide to grow cannabis indoors, there are actually plenty of mediums to choose from- soil placed in pots/grow boxes, rockwool, perlite, coco coir, vermiculite and clay pellets or pea gravels.

Common Medium Used for Growing Marijuana Indoors

Here are some of the most common indoor marijuana medium used to successfully grow your own weed plants indoors. Read on.


It can be a mixture of compost, sand, peat moss, animal manures, fir bark and other organic substances. Do not use soil from your garden plot outside as it may contain harmful organisms that can expose your weed plants to various soil-borne diseases. For new growers, using a commercial potting soil is a good start. Aside from its availability, the use of soil as medium for cultivating pot indoors gives several advantages to growers. Its natural buffering ability to keep pH stable is one. In choosing the kind of soil to be used as medium, ensure that it has a correct texture and good draining properties to prevent soil compaction and avoid water from being stagnant at the bottom of the container.


This is an ideal growing medium to use for hydroponic indoor growing because of its water-holding capacity. Use rockwool slabs if you are growing several marijuana plants. Start with rockwool cubes measuring about 2.5 cm and fit these smaller cubes into larger ones if you notice that roots are starting to outgrow the current cubes. Because of it is naturally high in pH, it is best to get rockwool cubes from a hydroponic shop to ensure you are getting the best rockwool for growing pot. Get the pH of the rockwool before using. If pH is high, neutralize it by soaking the cubes or slabs for one hour in water having a pH of 5.5

Clay pellets

These are marble-sized balls best used as medium for hydroponic growing but much safer to use than the rockwool cubes because they are sterile and neutral in pH. Also called as lightweight expanded clay aggregate, this medium can absorb lots of water while releasing it very slowly, so you do not have to worry about getting the medium very dry. It is one of the popularly used mediums today because of its good drainage property. It is also cost-effective because clay pellets can be sterilized and reused.


It is a good medium to use for hydro set-up because it is porous and has an excellent water-holding capacity. Before using in hydroponics, perlite should be thoroughly washed. One of the drawbacks of using perlite is poor root-holding ability, so it is best to use with other growing medium.

Coco/Coco coir

It is a reusable medium in the form of croutons, mats and compressed bricks and made from coconut husk fibers. It is a good medium for growing weed indoors because of its fibers that provide good aeration, proper drainage and water retention for the cannabis plants.

In choosing the medium to grow marijuana indoors, look for these properties to ensure that you will be growing healthy marijuana plants: good drainage, neutral in pH, good aeration, water retention and allows good root formation.

For a complete growing marijuana guide, check out the Growing Elite Marijuana eBook.