Best Soil For Growing Marijuana

by Liam | Last Updated: July 8, 2020

When picking out the best soil for growing marijuana, you need to keep certain requirements in mind.

It’s not as of you should go to the local nursery or big box store and my Miracle Grow ® or just any potting soil.

Most of the commercially made potting soil have nutrients added to the mixture; which may not be good for the overall growth of cannabis.

I mean, lets be honest… we all know of someone, even perhaps ourselves, who used Miracle Grow ® during one of our first attempts at growing marijuana.

best soil for growing marijuana

In this article you will learn:

Most veteran growers will cringe when they hear about this, but deep down they are remembering their own grow before they discovered the best soil to grow marijuana.

The right soil can make or break your cannabis grow. At a minimum, take these six soil conditions into consideration when determining which soil is best for growing cannabis.

  1. pH level
  2. Texture
  3. Water retention
  4. Nutrient composition
  5. Drainage
  6. Loam soil

When shopping for the best soil for marijuana, you want to make sure that it has water retention, a good pH level, a healthy nutrient composition and allows for good drainage.

So how do you determine which is the best soil for growing cannabis? 

pH Level

The best soil for marijuana to grow in will have a pH level between 5.8-6.3; but the closer you are to 6 is the best. This may be a small “window” frame of the pH level, but if the levels differ too much, too frequently, you risk the chance of the plant dying.

Having a good soil pH level tester may be a tool you’ll want to consider as your growing and gardening of cannabis continues.


When you run the soil through your fingers, you can get a real “feel” for the texture. It should feel light and the granules loose.

The lightness comes from additives, such as perlite (explained more in next section). The characteristics of the soil being light allows for more oxygen to get deep into the soil and reach the plants’ roots.

Nutrient Composition

Even though most recommended soils for growing marijuana has nutrients mixed in already, they rarely last for more than a month once the bag has been opened and soil removed.

So mixing your own nutrients is important to add to the plants’ daily routine. You want to make sure you have perlite, a grow medium and conditioner, in the soil too.

Perlite will help protect the plants if by chance you over water and it helps maintain the pH level of the soil throughout the grow.


Too much moisture in the soil for growing cannabis can be detrimental for your plant. If, when watering, you notice the water pooling, or sitting on top, of the soil, you may have to find another soil.

Water sitting on top of the soil means it isn’t very porous and the water and nutrients are not reaching the plants’ roots. This can lead to smaller yield and the plant even dying. 

Getting the nutrients to the roots is too important and you can always transplant your cannabis. When changing the soil midway through a grow can cause some stress to the plant, but the best soil for your marijuana plant replaces any questioning of transplanting.

Water Retention

Just as soil that doesn’t allow for good drainage, you also have to consider how much water the soil can hold.

The best soil for growing marijuana will not only allow for good drainage, but will also retain enough water for the plant to thrive until it is “fed” again. 

Loam Soil

What is a good loam in soil? The best way to explain loam is what the soil is composed of. A good loam soil will have equal parts of sand and silt with a little less of clay mixed in.

Sand’s main contribution to the soil is that it is good for aeration and drainage, but is not good about maintaining a good moisture level for your plants. Whereas clay generally doesn’t allow for good air flow or letting roots grow through it.

Think about when ancestors would build a house; they used clay to fill in holes in the wood, rocks or whatever building material they were using.

The silt is what, more or less, holds the soil together. Think of it as the “glue” of the soil. 

There are ways to test soil for loam, but when looking for the best soil for growing marijuana, these tests can be time consuming and your plants aren’t going to wait. They need their freshly developed roots in some good soil now.

Best Soil For Growing Marijuana

Now that you understand more about what constitutes good cannabis soil, here are 4 options you can buy right now to get started.

Fox Farm

If you click this link and make a purchase, we earn a commission at no additional cost to you.

Happy Frog

If you click this link and make a purchase, we earn a commission at no additional cost to you.

Mother Earth

If you click this link and make a purchase, we earn a commission at no additional cost to you.

Bush Doctor

If you click this link and make a purchase, we earn a commission at no additional cost to you.

Feel free to drop me a line if you have any questions.