How To Choose the Best Soil for Cannabis

Many people keep herb gardens in their kitchen windowsills. Having farm-to-table access to fresh, organically grown herbs makes mealtime better. The same concept can be applied to cannabis. When you grow your own cannabis, you’re keeping yourself in a fresh supply of your favorite strain. 

There’s nothing more satisfying about homegrown cannabis. Growing and maintaining a healthy and thriving cannabis plant is hard work, but that work is worth it for many people. The foundation for growing the perfect plant begins with the soil. 

What To Consider Before You Choose Your Soil

If you’re new to gardening, you might be surprised to learn how many types of soil there are and how different they can be. It’s not as simple as putting fertilized dirt in a pot. Every plant thrives better in a different type of soil. Some of this is according to the plant's needs, and some of it relates to your gardening style. 

Certain types of soil may reduce the amount of maintenance needed to keep cannabis healthy, making them easier for first-time gardeners or multitaskers who can’t devote a wealth of time to their plants on a daily basis. All soil requires maintenance, and the type of soil you choose will dictate the type of maintenance necessary

The Weight of the Soil

Cannabis plants develop a complex root system, and those roots require a lot of oxygen. Heavy or dense soil will smother the roots, throttling their growth or causing them to fail to thrive. 

Any soil that feels like clay or becomes dense and flatly packed when wet is a poor choice. Soil with the texture of loose brown sugar will allow for optimal airflow. 

How the Soil Interacts With Water

Every soil needs to have a perfect balance of retention and drainage. If water runs to the bottom of the pot, and can’t get out, it drowns the plant. If water quickly escapes the pot, the roots won’t get enough of it to sustain themselves. 

Part of drainage depends on the soil, but the container you use to plant your cannabis will also play a role. Choose a planter with adjustable drainage. It will serve as a safety net.

The Soil’s pH Levels

The optimal pH level for growing cannabis plants is 6.0. While 5.7 or 6.2 won’t destroy your plants, they won’t reach their full potential when they’re flowering. The soil won’t retain a perfect pH throughout all stages of the growing process. 

You’ll need to monitor pH consistently and adjust when necessary. 

The Nutrient Density of the Soil

Just about every soil you purchase will come with starter nutrients. These nutrients will feed your plant for a few weeks. It helps to choose soil with starter nutrients that are matched appropriately for the needs of cannabis. There are plenty of soils designed for that purpose.

When those nutrients run out, it’s up to you to supply additional nutrients. You can do this by incorporating cannabis-specific nutrient mixes. They’re a straightforward solution that will work wonders if used as directed. If you’re an experienced gardener, you can use your own compost or worm castings for this purpose. 

Soil Characteristics for Healthy Cannabis Plants

There are four different types of soil. Two will work well for cannabis, and two won’t. 

Clay soils are very rich in nutrients, but their density and weight will smother the roots of your cannabis plant. Sandy soils drain perfectly, but a little too perfectly. They don’t retain any water, and you’ll constantly need to water your plants. This makes it difficult to spend time away from your plants.

Your two best options are loamy soil and silty soil. These each come with unique advantages and disadvantages, but they’re both valuable options for budding cannabis growers. 

Loamy Soil

Loam is excellent for growing a lot of things. Cannabis and berry plants thrive in loam. Loam is a special mixture of sand, silt, and clay designed to provide the benefits of each type of soil, but without the disadvantages. You’ll get the drainage of sand, the nutrient retention of silt, and the water retention of clay. Loam checks every box.

The only downside is that loam is difficult to mix on your own, and pre-mixed loam tends to be more expensive than other types of soil.

Silty Soil

Silt is the first-time gardener’s best friend. It’s easy to maintain a nutrient balance with silt, and it does a great job of retaining water. It’s inexpensive and can be used to grow a wide variety of crops, making silt a versatile option for people looking to grow more than just cannabis. 

Silt’s biggest downfall is its drainage. Silt usually drains well, but when it starts retaining a lot of water towards the bottom of the container, it gets a bit stopped up. If you use silt, you need to be sure you’re giving your plants the ideal amount of water to avoid drainage issues. 

Should You Make Your Own or Buy Your Own Soil?

Experienced cannabis growers usually have solid opinions when it comes to the DIY vs. buy debate. Neither option is bad. Prepared cannabis soil is designed to contain everything your plants need to thrive. All you need to do is replenish the nutrients every few weeks. The companies that produce prepared cannabis soil often sell nutrient packs designed to work with the soil. You don’t have to think twice about it. 

People prefer to make their own soil mixtures for one of two reasons: they either have a very specific growing strategy that works for them and need their soil to meet several essential marks, or they feel as though they’re saving money by mixing the ingredients themselves. 

They’re both right and wrong. Growers who have a magic formula they love should stick to that formula. New growers will require more experience growing cannabis before they reach a point where creating a custom formulation makes practical sense.

The DIY method is the wrong method if you believe it’s going to save you money. You’ll need to purchase larger quantities of every nutrient and additive individually and blend everything yourself. 

Your time and labor are worth money, and so are the additives you’re purchasing. If you only plan to grow one or two plants at a time, going the DIY soil route can be substantially more expensive. 

The price of a 50-liter bag of perfectly pre-mixed soil is usually less than the cost of one bag of unmixed ingredients like coco coir peat. 

We’re always down for a fun DIY project, but this one might not make the most sense economically. If you still need to buy seeds, containers, a grow light, and other growing supplies, it’s more efficient for your grow project budget to opt for cannabis potting soil. 

Soil Additives To Look for

Many pre-mixed soils that are excellent for growing cannabis won’t state so on the packaging. This is due to the legal standing of cannabis in most states. Instead, companies try to communicate through branding and marketing that their soil mixes are perfect for cannabis. 

If you see soil packaging that is overtly decorative and looks like something out of the 1970’s, the chances are high that the brand is attempting to appeal to cannabis growers.

If you’re not sure, check the ingredients mentioned on the packaging. Soil mixes intended for cannabis should contain at least three things. 

Coco Coir

Coco coir is a fiber derived from the husks of coconuts. Coco coir is naturally very light. It helps to promote drainage and aeration around the roots of your cannabis. Any potting mix that prominently features coco coir is usually a good bet. 

Worm Castings

“Worm castings” is a nice way of saying worm poop. Fertilizer comes from worms. In addition to worm castings, look for guano (bat manure) and humus (composted leaves and plant material). These are wonderful soil amendments that improve the quality of the soil and boost its nutritional properties. 

Keep Your Harvest Fresh

When it’s time to harvest, dry, and cure your flowers, the last thing you should do is stick them in a clear glass jar or a zip-top sandwich bag. You worked hard to keep that plant alive. Honor that hard work by storing your cannabis the way it was meant to be stored.

Stori is a cannabis storage case with six durable light-proof, air-tight storage pods and color-coded child-resistant lids. You can label the lids with the strain and the date of your harvest. The 6 Stori pods can store up to 1.5 oz of flower. 

The lids are designed to work with size 1 Boveda humidity packs, turning each pod into its own humidor that will preserve the terpenes and maintain the freshness of your beautiful harvest. 

Sources:

Garden Soil Testing | Clapp Library

Coconut Coir: What it is and How to Use it in the Garden | Good Gardening

Benefits of Worm Castings | Mindful Waste