Is It Better to Make Your Own Soil for Growing Cannabis?

In this article, I will explain the benefits of making your own soil, the importance of organic inputs, the qualities and properties good soil should have, the signs your soil is of poor quality, and the use of compost tea and microbial inoculants.

What Are the Benefits of Making Your Own Soil Mix?

When it comes to practicality, buying soil in a bag ready to fill your pots with is advantageous, so why would you go through all the trouble of making your own soil? Whilst completely ready-to-use soils may have good drainage and contain all the nutrients a cannabis plant needs from seed to harvest, making your own soil allows you to decide the exact composition of the organic inputs and their properties.

Growing cannabis with soil also allows a home grower to take their organic knowledge and experience to another level. Learning about the different organic inputs and their roles, and having a firm grasp of the soil food web, are key to producing superior-quality soil. 

Growers who choose to make their own soil also plan to recycle it after every harvest. Not only does this save money, but it also eliminates the need to buy new soil every time you start a new grow.

Ready-to-Buy Soil vs Homemade Soil

When we compare the pros and cons of buying soil in a bag ready to go, or starting from scratch and adding a big list of organic inputs, you see the benefits of each. Below are the advantages and disadvantages of each, to help you decide which is the better option for you and your circumstances.

Ready-to-Buy Soil

• You do not need to source the organic inputs
• There is no need to mix and blend the soil
• The soil will contain enough nutrients until harvest time
• Having soil delivered or picking it up in the car is easy
• You can buy a large quantity of soil at once
• The soil may be old and have sat around for a long time
• Microbial activity may be minimal or non-existent
• They may or may not have good drainage
• The soil will be made with perlite and have good drainage
• You can buy 25L or 50L soil bags, depending on your needs
• Garden centres sell soil, making it easy to source
• Soil can be cheap to buy when shopping online

Homemade Soil

• You need to buy all of the different organic ingredients
• The ratio of inputs is up to you 
• You can add any ratio of perlite and vermiculite 
• There is the perfect balance of micro and macro nutrients
• You can create a top mix dressing to apply every 2-4 weeks
• The soil will be supercharged with beneficial microorganisms
• Soil can be recycled with organic inputs after every harvest
• You do not need to buy new bags of soil after every grow cycle
• Seedlings and clones will thrive in custom soil

What Qualities Should Homemade Soil Have?

Once you have made your own soil blend, you will need to check that it has the following properties to ensure ultimate plant health and vitality.

• The structure of the soil should feel spongy and airy
• There will be a high ratio of perlite for good drainage
• The colour of the soil will be a rich dark brown and black
• The pots can retain water without becoming oversaturated
• Water can drip through the base of the pots easily
• Worm castings should be fresh and contain worms
• There will be a sweet and earthy aroma 

Signs That Soil Is Not of Good Quality

If you are not experienced with organic gardening, determining whether the soil you bought is any good can be difficult. Have a look at the list below if you are not sure.

• The soil feels dense and thick
• The soil remains waterlogged after watering
• There is no drainage at the base of the pot
• The odour of the soil smells rotten 
• The soil contains no perlite for drainage
• There are no signs of worms
• Pots take days before they are dry again
• Flies and pests are living in the soil

The Different Organic Inputs You Can Use

Everyone has their own preferred soil mix. There is no single formula, but the super soil recipe found online is a popular and highly successful method. Below is a list of all the organic inputs used for super soil.

• High-quality organic potting soil
• High-quality earthworm castings
• Steamed Bone Meal
• Soft Rock Phosphate
• Blood Meal
• High Phosphorus Bat Guano.
• 3 cups Kelp Meal.
• 3 cups of Alfalfa Meal
• 2 cups Azomite.
• 3 cups Oyster Shell Flour
• 1 cup Dolomite Lime
• 3/4 cup Epsom Salts
• 2 tbsp Humic Acid.
• 2 cups Mycorrhizae

Combining With Organic Compost Tea

Organic compost teas are an excellent way to make nutrients at home that are teeming with billions of beneficial microorganisms. All you need is a bucket, dechlorinated water, an air pump, an air stone, and some humic acid as a food source. 

By brewing organic materials for 24 hours, such as compost, worm castings, bat guano, or all three together, you will create a plant tonic that supercharges the soil even more and provides a rich, slow-release of nutrients back to the roots. Organic compost teas also enhance terpene production and the flavour of cannabis.

Autoflowering cannabis seeds require fewer nutrients than photoperiods, so it is best to feed autos a rich, complete soil specifically designed for cannabis and a mild liquid nutrient solution.

Inoculating With Microbial and Fungal Tea

Whenever I make a custom organic blend, even though the worm castings and compost contain beneficial bacteria and fungi, I like to use bacterial inoculants to supercharge the soil. A soil culture teeming with billions of aerobic bacteria and fungi will also provide greater resistance and protection against harmful pathogens. You can either sprinkle the powder into your soil or make a microbe liquid brew using a pump and an air stone.

Top Dressing Your Soil

Top dressing is adding a new layer of organic material to the top of the soil. This depends on the type of top dressing you use. I recommend applying a 1-inch layer every 14 days for pinnacle plant health.

My Final Thought

Buying new bags of soil every time you harvest can be advantageous if you find making your own super soil too much work. However, if you want to learn about organics, permaculture, and the importance of a healthy soil food web, I encourage you to take on the challenge of making super soil.

There are many benefits to becoming an organic mad scientist, and, from my experience over the years, super soil produces the best-tasting buds and also aroma when drying cannabis.  It may seem like an arduous task sourcing all the different organic inputs, but in the long run, it is well worth it. 

You won’t ever need to take that dreaded trip to the grow shop and fill the car up, and then carry hundreds of litres of soil upstairs! Give super soil with organic compost tea, and try it and you will be glad you did!