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When it comes to growing marijuana, it is vital to choose a soil type that will support your plants and help them grow as perfectly as possible. At a basic level, soil is described as the uppermost layer of the earth, where plants grow. It is a mixture that consists of rock particles, clay, and organic remains. However, when trying to set up an ideal environment for high-quality marijuana plants, there are so much more to put into consideration. Soil varies in a number of ways, such as:

  • Water retention
  • pH level
  • Nutrient makeup
  • Drainage
  • Texture

In this article, we will examine the qualities that make up the perfect soil for marijuana and help support a healthy grow.

Qualities of good cannabis soil

Generally, soil has a mixture of clay, silt, loam, and sandy textures. Most likely, you have had an opportunity of getting your hands dirty, and you have noticed these variations. Apparently, the texture greatly influences the overall structure of the soil; hence, when it comes to planting, be mindful of its attribute.

Sandy soils

  • Lower pH
  • Large granular size
  • Pros – easy to work with, high oxygen levels, drainage, and prevents compaction
  • Cons – Dries out quickly, poor water retention, and nutrients get washed away

Clay soils

  • Higher pH
  • Small granular size
  • Pros– Retains water, provides minerals, and stabilizes plants
  • Cons – Heavy soil, poor drainage, and hard to work with

Silt soils

  • Medium granular size
  • Pros – Retains water, naturally fertile, and stabilizes plants
  • Cons – easily compacted and poor drainage

While some plants do well in their native soils which largely comprise one of these compositions, marijuana plants best thrive in soils which have a blend of these three textures. This mixture or blend is known as loam.


  • Near neutral pH
  • A mixture of silt, clay, and sand
  • Pros – Water retention, easy to work with, naturally fertile, support microorganisms, drainage, and high oxygen levels.
  • Cons– can be costly

How to identify loam soil

The perfect way to spot loamy soil is by feeling it. When squeezed, loamy soils form a drooping ball which holds its structure for a short time before breaking in large chunks.  On the other hand, clay soil can compact into a rigid ball which does not disintegrate easily while sand is difficult to compact.

Most potting or gardening soils are usually loam soils. Its composition looks rich, and the color appears hearty and dark. Beyond color and texture, the soil smells rich and alive.

Buying the perfect soil for growing marijuana

While looking for cannabis soil, you will certainly be overwhelmed by the available options at your local garden store. Why is that? Most of the soils sold in these stores are loamy just by definition and not of genuine quality.

Besides the basic structure of soil, look at the microorganisms, nutrients and other modifications that will improve your soil. Your soil choice should be flooded with phrases like:

  • Worm castings
  • Bat Guano
  • Biochar
  • Perlite
  • Compost
  • Peat Moss
  • Fish meal
  • Bone meal
  • Plant food
  • Glacier rock dust

These are just a few common examples of modifications or amendments which are listed on different soil types. Heavily amended soils usually have a long list which outlines all organic nutrients present. Sometimes, some vendors create soils which have a good soil structure with base nutrients; however, allow you to incorporate other nutrients as you desire.


For most beginners, it’s good to purchase potting soils, since they already have the necessary nutrients in them. These soils will definitely see your cannabis plants through their growth cycle. Basically, you don’t have to add anything to improve their fertility.

For those that wish to cultivate their cannabis outdoors in a garden, it is always good to seek advice from experts in your local grow store or nursery. If you do not wish them to know about your cannabis grow, ask for a rich soil appropriate for tomatoes. Tomatoes thrive in similar soil.

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