Growing cannabis is easy - they don’t call it weed for nothing. You can literally stick a seed in the ground and watch it grow. But if you’re looking to grow the best possible crop you can (and why wouldn’t you?), you have to start with the right soil. Choosing the right soil for your girls is one of the most important aspects of a good grow.

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What Is pH And Why Does It Matter In Soil? 

pH stands for potential hydrogen and is used to define the acidity of a substance. pH levels go from 1-11, with 1 considered “very acidic” and 11 considered the most basic. Lemon juice, for example, has a pH level of 2. Pure water is considered neutral and has a pH level of 7.

Cannabis will thrive in soil with a pH level of right around 6. When soil becomes too alkaline (think 7.5 and above), the roots of the cannabis plant aren’t able to absorb the copper, manganese, iron, zinc, and boron ions present in the soil. When pH levels become too acidic (below 5.5), roots lose their solubility and don’t get the calcium, magnesium, and phosphoric acid they need. When pH levels get as low as 3-5 in temperatures above 80 degrees Fahrenheit fungal diseases can jeopardize the plant.

Different Types of Soil

At its most basic, outdoor soil comes in three different types: clay, loam, and sand. When creating the ultimate environment for your plants to thrive, however, there’s a lot more to your soil than the basics. Taking a look at each will help you understand why.

Ground Texture. Top View of a Dark dirt Soil. Close Up Macro View of Dirt and Stones. Background with Text Space. Full Frame. iStock / GalapagosFrame

Clay Soil

Clay soil has a higher pH, retains water, and contains vital minerals. On the other hand, it’s heavy, doesn’t drain well, and can be difficult to use.

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Loam soil is a combination of clay, sand, and silt. It has an almost neutral pH level, excellent drainage, does a good job at retaining nutrients, has high oxygen levels, and is naturally very fertile. Loamy soil is pretty much a weed grower’s dream.


Sandy soils have a lower pH, drain well, and have high oxygen levels. Sandy soils are also extremely easy to work with. They can also dry out rapidly and don’t retain water very well.

Buying The Best Soil For Your Plants

Marijuana plants in beginning vegetative stage up close, growing in tent. iStock / HighGradeRoots

Keep in mind that most soils you purchase at the store will be loamy, which is exactly what you want when growing weed. Shopping for soil can get extremely overwhelming, though. As a budding ganja grower, you’re going to soon find out that there are a lot of different options to choose from at your local grow store.

Your soil is your basic starting ground when growing cannabis. Some soil will be just that - a starting point to get you going. Other soils might have basic nutrients but will require you to add nutrients as you go. Then there are the soils that will have all the amendments and nutrients included that will help your plants thrive.

What exactly goes into an amended soil that will make your weed plants blossom into their full potential? Some common amendments added to soil will include:

  • Bat guano
  • Biochar
  • Bone meal
  • Compost
  • Fish Meal
  • Peat moss
  • Perlite
  • Plant food

While this list isn’t exhaustive of what might be added to amended soil, it’s a basic start. Heavily amended soils will contain more ingredients, which will require adding fewer nutrients through the growth cycle of your plants.

For the first-time ganja grower, it’s recommended to purchase soil that’s already amended. Regular organic potting soil will work (if that’s your only option), but you want to make sure you don’t purchase soil that has slow-release chemical nutrients. This can give your plants the incorrect nutrients at the wrong time, which could end up ruining your crop.

Ideal Organic Soil Choices For Growing Weed

Cannabis farming has come a long way, and there are countless soils available that will ensure your crop is the best it can be. The following soils are widely trusted amongst growers and are known to produce happy, healthy plants.

Roots Organics Original Potting Soil

Roots Organics Original Potting Soil has been a grower’s go-to for years. It’s composed with all the amendments your plants need, ensuring a healthy root system, excellent drainage, and continuous feeding of your potted plants. The ingredients added to Roots Organic Original Potting Soil include:

  • Coconut coir
  • Bat guano
  • Earthworm castings
  • Feather meal
  • Fish bone meal
  • Glacial rock dust
  • Green sand
  • Humic acid
  • Mycorrhizae
  • Peat
  • Perlite
  • Pumice
  • Soybean meal

Roots Organic can be a bit costly but is well-worth the extra money you end up spending. With this well-revered soil, you’ll grow the happy, healthy plants you’re going for AND increase your yields. Hands down, one of the best amended soils you can buy.

Fox Farm Ocean Forest

Fox Farm is another soil that’s been used by growers for years. Ocean Forest is a mix that several cannabis growers prefer, as it’s pH balanced, with plenty of nutrients added to it. It allows you to grow your weed without doing much but watering them, which makes growing your plants even easier. Ingredients added to Fox Farm Ocean Forest include:

  • Bat guano
  • Composted forest humus
  • Crab meal
  • Granite dust
  • Norwegian kelp
  • Oyster shell
  • Sandy loam
  • Sea-going fish emulsion
  • Shrimp meal
  • Sphagnum peat moss
  • Worm castings

Fox Farm Ocean Forest is another preferred soil that is widely available and allow your plants to thrive.