Top 7 Best Soil for Cannabis to Get for Abundant Growth in 2020!

To achieve a bumper harvest from your weed garden, you need to ensure that you are using the best soil for cannabis.

Cannabis is most often considered a weed because of its ability to thrive in diverse conditions though not really confirmed whether that is where the name “weed” is derived from.

It can be grown indoors, outdoors or in any medium as long as it gets the vital nutrients it needs to grow.

Indoor gardening of cannabis allows it to develop under closely monitored conditions. As a matter of fact, you incur no loss when farming weed indoors or if any, it’s very minimal.

Growing cannabis indoors, especially in a grow cabinet, ensures that you enjoy optimum privacy, plants are safer from pests and diseases, they are secure and out of reach from unauthorized hands and can produce maximum yields.

The key factor to consider before you start the indoor growing process is the medium. The weed grow medium can differ from the soil, clay pebbles, Rockwool, coir or in a hydroponic system among others.

Marijuana roots need plant feeds from which it absorbs the essential nutrients the plant needs to sprout.

How then can you ensure that your Cannabis gets sufficient nutrients? The sure way is to find the basics of good soil for weed.

So, What is the Best Soil for Growing Weed?

Cannabis plant in soil

Here are the key features of the best soil for cannabis:

  • Appears dark and rich.
  • Has a loose texture.
  • Drains well.
  • Retains or holds water without getting soggy.

The best soil for growing marijuana indoors is organic super soil and 420 fertilizer mix. It is possible to obtain this soil mixture in very easy steps.

All you need to obtain the organic super soil is to augment it with cannabis-friendly ingredients.

The 3 most important aspects of any soil are texture, drainage and water retention ability.

Cannabis is no different.

In order for your marijuana plants to germinate and thrive, a perfect mix of both water and oxygen is very crucial. Too much water or lack of enough water thereof can dwarf the weed growth process.

Subsequently, if there is not enough oxygen, the plants will droop and eventually die for lack of aerobic respiration. Always ensure that your marijuana plants are getting the right portions of those two basic elements.

The best soil for growing cannabis should also drain well and at the same time retain enough water. Soil with light texture is ideal for creating the best potting soil for weed.

Another key aspect is to ensure that the soil has the correct nitrogen to phosphorous ratio usually done in the composting and the vegetative stage.

It is also good to ensure that it has the right balance of fungus to bacteria. This ensures that you are able to attain the best soil mix for growing cannabis indoors.

Cannabis does well in slightly acidic soil and so you should try to find soil with a pH of 6.0 with a variation of minus or plus 0.2 or 0.3 respectively.

pH which stands for potential Hydrogen is a chemical scale that is used to specify the acidity or the basicity of a substance usually liquid substances.

Thus in simple terms, because soil contains water which is a liquid, it also has a pH and so the best potting soil for cannabis should always have a pH level of 6.

Top 7 Marijuana Soil Ingredients Reviewed 2020

There are several ingredients that can help you achieve the best soil to grow pot.

Here is a review of the top 7 marijuana soil ingredients that can be used to alter the soil to make it fit for growing weed:

The first step to achieving the best potting soil for marijuana is to find the organic soil that acts as the base. It contains no additives. Therefore, you need to find the basic ways to alter it to create the best soil for growing weed indoors.

The soil amendments process is not rocket science and is rather a very simple procedure that you can find.

All you need is to get a hold of the common ingredients that can alter the texture, drainage & water retention of soil to ensure that you obtain the best soil for marijuana plants. The ingredients include:


Perlite is highly recommended for organic gardening and is a material that contains the volcanic glass.

They are mined siliceous rocks that are very light, airy white-colored foam pellets or rocks that feel more like popcorns. Perlite has small cavities granules on its surface that traps and holds in moisture.

The perlite lightweight feature helps to aerate the soil by preventing soil compaction. The perlite material is usually composed of alkaline pH levels of 7.0 to 7.5.

The perlites are used to add oxygen while increasing the overall water drainage ability. Perlite is also used to enhance water retention.


  • Enhances water retention.
  • Boosts soil aeration and improves oxygen levels.
  • It helps loosen up heavy soil while preventing compaction.
  • Promotes root growth.
  • Improves drainage.


  • The fact that the Perlite material bears an alkaline pH level of 7.0 to 7.5 can result in fluoride burn on the foliage plants as weed does better in the slightly acidic soil.


Always use the recommended portions as too much or too little portions of perlite can interfere with the purpose of cannabis gardening.


Vermiculite material is obtained from superheated mica and it’s naturally sterile and thus does not foster any plant diseases. It can take the shape of an expanded structure that resembles a plate that traps in the air, nutrients, and moisture that are found in the potting soil mix.

Vermiculite is available in different sizes and used to improve water retention and to ease heavy soil.

It holds water much better than perlite but it is not as effective as perlite at adding drainage and aeration.

Vermiculite levels of pH are more neutral and usually fall around 6.5 to 7.2, and that makes it the best for weed farming.


  • Improves water retention.
  • It helps to loosen up heavy soil.
  • Harbors no plant diseases.
  • Enhances drainage and aeration.
  • The pH level is more neutral.


  • Does not aerate as much as perlite
  • A bit more expensive than perlite.


Ensure that you apply the right proportions of Vermiculite to achieve the best results.

Coco Coir

It is made from the fibrous coconut husks or from the inside of a coconut shell. It can be dark brown fiber if it’s obtained from ripe coconuts or a white fiber if it is from unripe coconuts.

The components are used in potting soil and can be mixed to obtain the best soil for growing weed. It is preferable to use the brown coir for hydroponic use.

Coco is an organic compound that helps to increase the absorbency and drainage of the potting soil. Coco Coir contains manganese, zinc, Potassium, copper and iron nutrients. It is usually amended in a potting mix as loose coco coir or as coco bricks.

Coco coir has three components which are coconut coir fiber, chips, and pith. It is good to ensure that you create a proper balance of these 3 elements to create the best soil for indoor growing.

The coco fiber helps add air pockets. Since the fiber is not absorbent, it helps create a free flow of oxygen to the roots of the plant. The coconut chips can absorb and hold water efficiently and help create air pockets as well.

The coco pith (peat) is spongy and helps absorb water. Its particles are minute and thus lack the capacity to hold significant amounts of air. The coir component is very woody and decomposes at a very slow rate.

When aged well, pith holds potassium and sodium nutrients. Coco has found its way to the potting mix as a support medium that is sterile and resists fungus development naturally. The production of coir varies with different gardening uses.


  • Absorbs water more readily and retains it without waterlogging.
  • Loosens the soil texture and improves drainage.
  • Its antifungal properties protect plants from Phytophthora, Pythium and other fungal root infections.
  • Improves water retention and with its use, roots tend to develop faster.
  • Coir lightens up the soil and thus it doesn’t become heavy after adding coco coir.
  • Deteriorates slowly creating soil air pockets and thus prevents root rot.


  • Has a neutral pH which may not be suitable for plants that prefer acidic soil like the weed.


To attain the best soil for indoor cannabis growing, ensure that you are aware of the products nutrition mix and make adjustments as necessary.

When shopping for coco coir, be sure to select the right coir for your purpose.

Worm Castings/ Vermicompost

Worm castings are the little miracles that are easily found on earth and they are the topmost secret to Mother Nature’s unbelievable plant yield results.

Pure worm castings are rich in quantities of water-soluble nutrients that help improve soil texture, moisture retention, and drainage.

The worm castings help plants to easily absorb all the essential nutrients as they crush and uniformly mix the soil nutrients and trace elements in the soil. They help to add a natural source of nutrients that integrate slowly in the soil.

The worm castings also have a high concentration of the beneficial microbes and bacteria that is added to them in the digestive process by the earthworms. It contains high levels useful microorganisms because of going through the worm’s digestive system.

The worm castings also help to improve the soil structure and aeration as they don’t compact together. This subsequently allows the roots to grow fast and fibrous which then assists in rapid growth and development of your weed plants.

They contain an absorbent organic matter that holds the required amounts of water needed by the roots and as a result, increase the soil water retention capacity. Their shape helps the water to drain easily.


  • Worm castings have higher levels of hummus than soil which enables them to hold more water and keeps the soil aerated.
  • Improve soil texture, moisture retention, and drainage.
  • Have components like cytokinins and auxins that act as plant growth promoters.
  • Have 20 times as much microorganism activity as plain soil.
  • Make a non-toxic fertilizer.
  • Just a handful is enough which makes it very affordable.
  • Increase the soil water retention capacity


  • Can have a noticeable earthly odor.


Worm castings are a great fertilizer that can help you create the best soil for weed.

Bone meal

Bone meal is a kind of farm fertilizer made from steamed animal bones. It is usually grounded into a fine powder and is rich in various nutrients like phosphorous and calcium.

Calcium helps in the formation of healthy cells. It also helps the plants move and retain other elements within themselves.

It can be fortified with other nutrients like nitrogen that plants need to produce green and flourishing foliage.


  • Helps the weed to grow and photosynthesize effectively.
  • Helps plants build a strong root system.
  • Increases flower and fruit development.
  • Used in the formation of healthy cells.
  • Helps plants move and retain other elements within themselves.
  • Does not burn plants if applied in large quantities.


  • Not suitable for all types of soil.
  • Does not contain everything a plant needs to bud.
  • It is only accessible to plants that grow in soil with pH levels below 7.


The directions of use vary with different brands. Check the package labels to determine its usage as it can be used in several different ways.


Pumice is a favorite amendment among a majority of farmers. It is natural lightweight and porous material that helps to naturally absorb water and later release it slowly to the soil.

Pumice aerates the soil, provides good drainage and does not wash away with frequent watering. It does not break down or compact with age.

It is ideal to create small garden beds and potting mix for containers. It can retain a significant amount of water and moisture and thus the weight can differ from bag to bag.


  • Aerates soil.
  • Enhances soil drainage.
  • Retains soil moisture.
  • Does not wash away, break down over time or blow away.
  • Can enhance all types of soil.


  • Pumice is twice the weight of the potting soil.
  • Pumice is usually sold by volume and not by weight.


A definite must for good yielding cannabis buds.

Dolomite lime

Dolomite lime is a pretty rock that is mostly used to treat soil that is too acidic which is commonly known as “sweetening” the soil.

It helps to adjust the pH levels of the soil so as to make it good for growing weed. It is added before you plant to help create a healthy condition for your marijuana plants.

It is composed of portions of calcium and magnesium, both of which are quite essential for the marijuana to thrive. It helps to speed up composting process which makes it a nutritious fertilizer mix.


  • Helps adjust the soil pH levels.
  • Promotes healthy plant growth.


  • Has a high ratio of calcium to magnesium where too much magnesium causes problems like compaction and pest and weed problems.


Only use dolomite lime when you have a purpose and you really need it.

You can opt for a premixed combination of soil but if you prefer to make your own soil, try to use high-quality ingredients to make a good soil for growing weed.


To obtain the best soil for cannabis, you may need to consider many more ingredients that can be used for soil amendments besides the ones discussed in this article.

They may include but not limited to Composted forest humus, blood meal, Bat guano, Fish meal, Crab meal, Azomite, Greensand, Mycorrhizae, Leonardite, and Sandy Loam.

Always do tests before you use any soil amendments and ingredients and research for the best soil to grow weed indoors recipe that will be fit to make your cannabis plants to thrive.

I hope this guide will come in handy when the time comes to plant weed indoors and will help you come up with the best soil for growing weed indoors.

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