Medically Reviewed by
Jason Crawford

Article Last Updated on December 28, 2022

If you’ve thought about growing marijuana, there are a few things you’ll need to acquire before you take up cultivation. In order for your cannabis seeds to develop into healthy cannabis plants, they need the right soil, pH levels, proper grow lights, and an appropriate amount of nutrients. That will not only enable proper root development, but will also help you get a larger yield out of your plants.

In order to help you create good growing conditions, we’ll go over the top soils that can promote proper root growth and ensure your cannabis plant will produce resinous buds with abundant amounts of cannabinoids.

What Are the Ingredients of a Good Cannabis Potting Soil?

The type of soil you use to grow your cannabis plants will affect how good your plants turn out. The key factors that make up a good cannabis soil are the loose texture of the soil,  proper drainage ability, as well as good water retention abilities to make sure your plants have enough nutrients. 

Cannabis plants need both water and oxygen that they obtain from the roots. If the plants are low on oxygen because of overwatering, they can “drown” because of lack of air pockets at the roots. On the other hand, if there’s not enough water retention, your roots can dry out too quickly, meaning your cannabis plant will also dry out. 

And finally, the best soil has quality soil ingredients, and the most popular cannabis soil ingredients include:

  • Composted forest humus;
  • Sandy loam;
  • Peat moss;
  • Coco coir (or coco fiber);
  • Perlite;
  • Earthworm castings;
  • Bat guano;
  • Fish meal;
  • Crab meal;
  • Bone meal;
  • Blood meal;
  • Pumice;
  • Kelp;
  • Mycorrhizae;
  • Others.

Altering Texture, Drainage, & Water Retention to Get the Best Soil for Cannabis

In order to get the best soil for growing healthy cannabis plants, you might need to alter it, and below we’ll go over some of the most common soil amendments.


Perlite is a common soil amendment and you should definitely add it to your soil mix if the mix doesn’t contain any. Perlite can be added to the soil in quantities between 10-40% of the soil’s total volume. If you want more water retention, use less perlite. More perlite results in nutrients leaching faster from the soil, and less perlite will enable you to add more nutrients without burning your plants.


Vermiculite can improve water retention and lighten up your soil. It can be used together with perlite, and some growers prefer to do this since vermiculite is better at water retention, and perlite is good at adding aeration. If you mix the two together, they shouldn’t be more than 50% of the soil.

Coco Coir

Coco coir is an ingredient added to soil that’s made from coconut husks. Before you use coco coir, you should rehydrate it. It’s a great option for growing cannabis plants since it improves water retention, helps roots grow faster, but doesn’t add much weight to the soil. Although some growers prefer to grow cannabis in pure coco, others use it as an amendment in quantities between 10-30%.

Worm Castings

Worm castings improve the soil’s texture, and also help with drainage and moisture retention. Moreover, they add natural nutrients to the soil as well as high levels of beneficial microorganisms. If you’re adding worm castings to your soil mixture, use about 30%, although adding more isn’t likely to burn your plants.

Review of Popular Soil Mixes

When thinking about what potting mix you should choose for growing marijuana, you’ll benefit from learning more about some popular soil mixes that are available on the market. 

Fox Farm Happy Frog Soil

If you’re looking for a soil mix that’s great for seedlings, this soil is the way to go. Since it has less nutrients, it’s good for the beginning stages of cannabis cultivation, and it’s a great option if you’re planning to add extra nutrients in the water you use for watering your plants.

Fox Farm Coco Loco Soil

Coco Loco is a soil mix that has enough nutrients for a period of 2-3 weeks, after which you’ll need to add extra nutrients to your plants. It’s a great potting mix that helps plants grow healthy and is more resistant to overwatering or underwatering.

Fox Farm Ocean Forest Soil

Ocean Forest is a soil mix with a number of beneficial nutrients packed in the mix to ensure you get the most dense and high-quality cannabis buds. It contains ingredients like earthworm castings, bat guano, fish meal, and crab meal which are all ingredients that cannabis plants love.

Since this is a potent mix, it may result in nutrient burn in the early stages of development, however, once the plants get to the flowering stage, they need a lot of nutrients, and Ocean Forest will provide just that.

Organic Potting Mixes

Finding quality organic potting soil may be a great option for your cannabis plant since those soils don’t have chemical slow-release nutrients in the mix. Even though this soil will contain organic matter (humus) that has plenty of nutrients, it will only last for a couple of weeks. After that period, you would need to supplement your plants with Phosphorus, Potassium, and other important nutrients, especially in the flowering stage when they require a lot of them. 

You can even try out the Miracle-Gro organic potting mix, as it doesn’t contain chemical nutrients. The only downside to using Miracle-Gro is that it retains moisture and that may cause your plants to develop mold. Therefore, other organic potting mixes may be a better option.

Super Soil (Living Soil)

“Super” soil is a term coined by cannabis growers and it refers to soil that has added slow-releasing organic nutrients, and is composted for a few months. As a result of the composting process, growers get soil full of microorganisms that are located around the plant’s roots – living soil. These microorganisms deliver nutrients to your plants throughout their lifecycle, and eat the sugars that are secreted by the root system. Don’t overwater this type of soil, because it can wash away important nutrients. You just need to give your plant enough water to saturate the soil, and your plant will grow a healthy root system and rich buds.

Final Thoughts on What Is the Best Soil for Cannabis?

If you’re looking for good soil to plant your high-quality marijuana plants in, make sure that the one you choose contains beneficial microbes, organic material, and good soil ingredients like humus, peat moss, coco coir, perlite, vermiculite, and similar ingredients. The soil should be dark, rich (sandy soil doesn’t contain a lot of nutrients), and have a light and airy texture. 

Some cannabis growers prefer to make their own DIY soil rich in nutrients, instead of buying premade soil mixes that are tailored to the cannabis plant’s growth phases. Whichever option you choose, make sure your plants have enough nutrients, suitable light, adequate amounts of water, and balanced pH levels. Happy growing!

A passionate advocate for the benefits of cannabis. Fraser Horton, who has a background in botany and a strong love of nature, has spent years researching how cannabis affects the body and mind. He established Leaf Nation in 2020, where he has devoted himself to educating people about the legalisation of marijuana and its safe and responsible use. Fraser is committed to highlighting cannabis’ potential for improving wellness and working to dispel the stigma associated with its use.


The information presented on this page is provided as a public service to aid in education and is derived from sources believed to be reliable. Readers are responsible for making their own assessment of the topics discussed here. In no event shall Leaf Nation be held reliable for any injury, loss or damage that could happen if using or abusing drugs.