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Cannabis hemp seed potting mix planting soil

DIY Potting Mix for Marijuana Growers

Making your own potting mix can be a great way to advance your marijuana garden, or even a cheaper alternative for those growing marijuana for the first time. Whether you’ve grown before or it’s the first time, home making your own potting mix is the best way to ensure a high-quality soil.

At WeedSeedShop, we’ve delved intensively into how to choose your soil for optimum results from your garden. But the best way to get the conditions of your soil perfect is to of course, create your own. The advantages of making your own potting mix are that it is affordable, and this method gives you complete control over the balance of nutrients.

Making your own soil enables you to produce the highest quality marijuana possible out of your growing endeavour. This is not difficult and is entirely possible for those who have just started growing.

Why go down the road of DIY?

Choosing the right soil is imperative to growing quality ganja – it is where the whole thing begins! Even though there are quality potting mixes available in stores, the truth is that in fact, their quality varies not only from company to company, but also from batch to batch.

Creating your own potting mix means you can ensure the quality of your soil every time you grow. It is much cheaper to create your own soil, especially if you make your own compost and work with dirt from your garden. Conveniently, you can store your batch of potting mix and it will last much longer than products that you buy in stores.

In fact, doing it yourself is imperative if you want to grow your own cannabis organically. Often what you purchase in stores is chemically enhanced and doesn’t contain the natural biomicrobials that make your growing endeavour an adventure into permaculture.

Creating your own soil is highly encouraged, especially because your marijuana plant is something you should take care of from the very beginning. Fortune favours the brave, those who adventure into the world of DIY potting mix!

Creating the base

There are two ways to create the base of your potting mix. The first one is to buy your basic soil from a store. The second way is to create your own soil from scratch. We will go through both ways to create the base of your potting mix.

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Making your own soil from scratch

To make your own soil, you are going to need to collect some ingredients. The point is that your soil should be full of “food-healthy” things that will promote soil that retains water and is also well aerated. Cannabis requires these qualities because root growth is imperative to a healthy plant. You also do not want it to contain nasty chemicals because these will eventually end up in your body.

The tools you will require:

  • A container to measure
  • A huge bucket to mix everything together
  • A water source (i.e. a hose or tap)
  • A fork
  • A separate container for soaking some of your ingredients
  • A sieve
  • A dust mask to protect against any particles (if you use organic materials this isn’t a huge deal, but still… safety first)
  • And all the ingredients that are about to be listed

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The ingredients you’ll need:

This material is a volcanic mineral that is used to retain moisture in the soil. It is sourced from many different parts of the world, and you can buy it online.

Vermiculite has been treated with heat in order to increase its water-holding capacity, and this is what is going to keep your soil very water absorbent. It also will retain some nutrients to make them available to your plants.

It does not rot or deteriorate at all, and basically stays exactly the same for the entire time it lives in your soil.

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  • 1 part pre-soaked Coco Coir Peat

This material is a waste product that comes from the coconut industry, and it’s a very environmentally conscious way to add food to your soil. It is generally considered more ethical than choosing peat moss, which doesn’t renew and can cause problems for the environment.

You can buy great organic compost for relatively cheap, or for even cheaper you can make your own compost. Compost is a great source of plant food, as well as all of the healthy bacteria that keep your soil alive. Your compost should be sieved before it is used in your potting mix.

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  • ½ cup or 1 cup of Worm Castings (or humus)

If you have your own worm farm, you can add this humus to your mix. If not, you can buy worm castings. This also makes your soil better able to retain moisture and nutrients to be able to feed your plants.

It adds helpful angels in the form of microbes to your soil, is also a source of food and overall, this is a great addition to your homemade soil.

A part just refers to however much potting mix you want to make. Be consistent with your parts and you can create as much as you want.

How to make your own base soil

  1. Make sure you have sieved your compost and pre-soaked your coir peat in warm water. Use directions according to how much coir peat you’ve got. The directions should be on the product you’ve purchased.
  2. Mix the coir peat with the vermiculite in a bucket.
  3. Add your compost!
  4. Be a good grower, and check the pH of your soil! You’re aiming for somewhere between 5.8-6.5.

Now, you’ve just made a little, or a lot of your own home-made soil. Below, we explain which nutrients you should add to your soil to create the perfect environment for marijuana.

You can keep feeding the ecosystem that is happening in your soil by giving it compost tea. It is a great thing to give your plants while they are growing, and it keeps the soil in good condition, too so that you can reuse it in future grows.

The name for this recycling of soil is, appropriately, Recycled Organic Living Soil (ROLS). Through this process, you can maintain the living ecosystem of microbial life inside your soil so it is constantly regenerating itself, making it richer with nutritional information. To acquaint yourself with ROLS, you can read our article about it.

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Buying base soil

The other way to create your base soil is to buy some good quality, organic soil. Well aerated soil that is easily penetrable is what you are looking for. Better quality soils usually contain ingredients such as peat moss (although as we’ve discussed, there are more ethical materials to use that are just as beneficial to cannabis), soybean, worm castings, compost, sand and oyster shell flower.

Make sure you check the list of ingredients in your soil. It should not contain any added nutrients. The problem with buying pre-mixed soils is that they are not made for cannabis, but for other regular house plants. The nutrients mixed into these will actually you’re your cannabis plants rather than help them.

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Adding nutrients

Whether you’ve made your own base soil or you are buying the base soil, you will need to supplement your soil with nutrients. Worm castings really are the best organic material to add for nutrients, but you could also add blood meal, Epsom salts, rock phosphate, dolomite, bone meal, azomite and bloom bat guano. These promote the volumes of potassium, nitrogen and phosphate.

Now, it isn’t necessary to add all of these ingredients to your DIY soil. However, if you nail it from the very beginning, you provide your plants a nutrient-rich soil without having to add nutrients in the future.

The benefit of making your own potting mix rich with natural nutrients is that the nutrients can be provided at a constant and steady rate throughout the grow. Having to feed nutrients throughout the grow makes the nutrient availability staggered rather than constant. This is why adding the above ingredients is highly recommended.

Make sure that you distribute the nutrients evenly over the soil. It means you have to mix it all very well. Grind your nutrients into as fine a powder or mix, and try and mix everything together as well as you can. It is important that they are evenly distributed in your potting mix so that you don’t end up with a batch of nutrient-rich soil and a batch of completely bare potting mix.

Now you are prepared with the best quality potting mix, homemade by yours truly. You know exactly what has gone into it, and in doing so you’ve created the perfect environment for your seeds to grow. Enjoy your home-made medium!

What is Good Soil For Growing Cannabis?

When it comes to growing cannabis in soil, unless you’re using a brand that is known for making soil that is specifically cannabis-friendly, there are a few things that you need to consider before starting a grow.

What should you look for in good cannabis soil?

I think most growers agree a good cannabis soil should look dark and rich, with a loose texture that drains well and can hold water without getting muddy (you want wet soil, not dirt-batter!). But beyond that, what do you look for?

The following video shows the soil texture you want (this is Coco Loco, an excellent soil for growing cannabis)

Some growers choose an amended and composted “hot” soil that slowly releases nutrients over time. With this type of soil, you typically just add water or natural supplements like worm tea from seed to harvest. Other growers prefer a lighter potting mix so they have more control, and give nutrients in the water once the plant roots have used up the nutrients in the soil. But which brands can you trust?

Some popular soil examples that I’ve used with good results include:

  • Almost any organic soil potting mix – If you can’t order special soil online, ask for the best soil at your local gardening store. You can use almost any organic soil potting mix to grow cannabis. I say “organic” because that cuts out a lot of potentially problematic ingredients like slow-release chemical nutrients (which often cause nutrient issues in the flowering stage by delivering too much Nitrogen). If asked what you’re using it for, say tomatoes. You should plan to start adding extra nutrients in the water by the time a plant is a few weeks old as the roots will quickly use up everything. Try to look for soil with a rich and dark but loose texture. It’s a good sign if you see little white pebbles mixed in (this is perlite, which makes soil drain better). If a soil looks like dirt or mud, it’s no good!
  • Roots Organics Original – This was the first soil mix I ever used to grow cannabis and I had a great experience. I’ve moved on to Fox Farm products because they were available at my local hydroponics store, and now I’m hooked on Coco Loco. But Roots Organics Original soil has been around for a while because it works great. As with most soil mixes, you will need to supplement plants with additional nutrients after a few weeks.
  • Fox Farm Happy Frog soil– This soil mix is relatively light on nutrients so it’s great for seedlings. It’s also suitable if you plan to give nutrients in the water from seed to harvest. If you don’t add extra nutrients, your plants will use everything in the soil up quickly.
  • Fox Farm Coco Loco soil– A coco-based soil mix with enough nutrients to last your plants for a few weeks. With Coco Loco, you should start supplementing with extra nutrients once plants are 2-3 weeks old. I personally like Coco Loco the best of any soil mix I’ve used. You can use it by itself and it’s also my favorite base potting mix for a “just add water” super soil grow. I feel like plants tend to grow happy and healthy while being more resistant to over or under-watering compared to the other soil mixes I’ve tried. It’s great soil for other types of crops too.
  • Fox Farm Ocean Forest soil– A “hot” soil mix with lots of nutrients packed inside. You can start seedlings directly in this mix though they may show signs of nutrient burn at first until they get adjusted. Ocean Forest has enough nutrients to last your plants quite a while, though you likely should still give extra flowering nutrients once your plants start making buds in order to get the best yields, density, and bud quality. Cannabis plants need a surprisingly lot of nutrients in the flowering stage and you don’t want to starve the plants right as buds are forming.
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Recommended soil nutrients:

    – These 3 bottles include everything your plants need from seed to harvest. The FF trio produces superb weed with any high-quality soil.
  • Learn about other cannabis-friendly nutrients

Important Cannabis Soil Considerations

  • Texture
  • Drainage Ability
  • Water Retention

Although that list looks vague and complicated at the same time, the requirements you want to meet are actually pretty simple; let me break it down!

Texture, Drainage & Water Retention

It’s easy to get caught up thinking about what nutrients and amendments are in the soil, and those are important, but perhaps the most important aspect of any soil is actually its texture, ability to drain, and overall water “holding” ability.

In order for a cannabis plant to grow and thrive, it needs a good mix of both water and oxygen at the roots at all times! Too much water and the plant roots can’t get enough oxygen (lack of oxygen at the roots is why plants get droopy from overwatering) but on the flip side if there’s not enough water retention the roots can be injured from drying out too quickly!

What gets the best results for growing cannabis is a soil with a light texture that is good at retaining water…but not too much!

Note: Don’t worry, there’ll be examples of good and bad soil in just a bit!

Signs of Good Cannabis Soil

  • Appears dark and rich
  • Loose texture
  • Drains well (doesn’t make a pool on top of your soil for more than a couple of seconds and doesn’t take forever to drain out the bottom)
  • Holds water without getting muddy (you want wet soil, not dirt-batter)

Example of “Good” Cannabis Soil Ingredients

Note: You’ll likely never see any soil mix with ALL those ingredients, but I wanted to share examples of common cannabis-friendly ingredients and amendments that often appear on the label of good soil

If you get the soil part right, you have almost everything you need to get to harvest! With the correct texture, drainage and water retention, you’ve got a perfect base. Add good soil cannabis nutrients, especially in the budding phase, and you should get to harvest with great results!

Example of happy marijuana plants in good soil!

More About Common Amendments to Alter Texture, Drainage & Water Retention of Soil


    Perlite is one of the most common soil amendments. It is highly recommended for any soil mix that doesn’t have some already.
  • Very light, airy white “rocks” that feel almost like popcorn and add oxygen while increasing overall drainage ability.
  • Add perlite to the mix (10-40% of the total volume). Use less perlite if you want better water retention and don’t plan on using a lot of extra nutrients. This is because a lot of extra perlite can cause the nutrients leach out faster from the soil. Add higher levels of perlite if you want to use a lot of added nutrients or supplements without burning your plants (since perlite helps prevent nutrient buildup).


    Vermiculite “lightens up” heavy soil and improves water retention.
  • Some growers use perlite and vermiculite interchangeably, though they’re not exactly the same. Vermiculite holds water much better than perlite, but is not as effective at adding aeration and drainage.
  • Some growers use a little bit of both. If you go high with vermiculite, you don’t want to go as high with perlite and vice versa. Together, perlite and vermiculite should never make up more than 50% of your soil!

Coco Coir

    Coco coir is made from coconut husks. It can be purchased as loose coco coir, in an amended potting mix, or as coco bricks which needs to be rehydrated before use (learn how to re-hydrate coco bricks). Sometimes you’ll find a “soil” mix that is pretty much all coco plus amendments, and these can be a great choice for cannabis. Coco has some unique properties that make it a good supplement for cannabis soil mixtures.
  • Coco improves water retention, but doesn’t make soil heavy.
  • Roots tend to develop faster and plants are less likely to suffer from overwatering in coco coir.
  • Some growers grow in pure coco, but if you’re adding it to a soil mix as an amendment, you might add 10-30% coco coir.

Worm Castings

    Worm castings is a nice way of saying worm poop, and cannabis plants love it!
  • Improves texture, drainage and moisture retention
  • Add a natural source of nutrients that breaks down slowly
  • Usually contains high levels of beneficial micro-organisms due to going through a worm’s digestive system
  • Add up to 30% worm castings in your soil (although it contains nutrients, it’s gentle enough that it’s unlikely to burn your plants even if you add too much)

Now here are a few examples of good and bad cannabis soil so you can see the texture you’re looking for!

Good Cannabis Soil
Rich and light composted soil. Since this soil doesn’t have a lot of perlite, it’s a good choice for a grower who doesn’t want to add a lot of extra nutrients or supplements in the water.

Good Cannabis Soil
Another light, rich soil mix with great drainage. Although there is a wood chip in this picture, for the most part the mix is completely composted and broken down. It’s normal to see some wood pieces in composted soil, but you don’t want to have to wait for a lot of wood to break down while your plants are growing – you want all that rich nutrient goodness to be readily available to your plant roots

Good Cannabis Soil
This soil has quite a bit of perlite, which is a good choice if you plan to feed heavily with nutrients and supplements since the extra perlite prevents nutrient buildup in the soil

Good Cannabis Soil
The plant is growing in organic, composted “super soil” which has enough amendments to last your entire grow, so the only thing you do is add water!

Here’s organic “super” soil up close

Bad Cannabis Soil
This soil is muddy, clumpy and waterlogged. It retains too much moisture, which makes it really easy to overwater your plants.

Bad Cannabis Soil
Cannabis soil should not have a whole lot of big visible wood chips in it. That means the soil hasn’t been fully composted, and all the nutrients and goodness in that wood is mostly unavailable to your plants.

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Bad Cannabis Soil
Although this seedling is over a month old, it has stayed tiny. Its growth is stunted by the thick heavy soil that holds way too much water and not enough air. Note how some of the soil looks like one solid object.

Bad Cannabis Soil
Don’t use dirt from outside! It almost never works, especially if it looks like this!

Suggested Brands for Cannabis Soil

Fox Farm Ocean Forest Soil

Fox Farm has been around for over 30 years and makes some of the most common types of “cannabis soil” (at least in the US). They have several great soil mixes, including “Happy Frog” which is a great choice for seedlings and clones.

Their Ocean Forest soil mix is “hotter” soil (higher levels of nutrients) that contains ingredients that cannabis plants love, including earthworm castings, bat guano, fish meal and crab meal. The nutrients contained in the soil will provide everything your plant needs for several weeks. Although it might give young seedlings just a touch of nutrient burn at first, they can be started in Ocean Forest soil and will soon be able to use the nutrients and start growing quickly. Some growers might put a little big of Happy Frog on top of a container of Ocean Forest, just to make it a little more gentle for seedlings the first week or two.

If you are willing to keep transplanting to bigger pots as your plant uses up the nutrients in the soil, you don’t need to supplement with extra nutrients. However, even if you grow in the same pot from seed to harvest, Fox Farm offers a complete nutrient system that is also formulated for plants like cannabis and goes perfectly with their soil to make sure your plant is getting the right levels of nutrients throughout its life.

This plant is growing in Fox Farm Ocean Forest Soil

Kind “Super” Soil (Living Soil)

When cannabis growers talk about “super” soil, they’re usually referring to soil that has been amended with slow-releasing organic nutrient sources, and then composted for several months (learn more about super soil).

The composting process creates a “living” soil that is full of microorganisms in the rhizosphere (area around the roots). Properly composted soil has nutrient sources that slowly break down over the course of your plant’s lifecycle. It very closely mimics what happens in nature.

Super Soil has a colony of micro-organisms living in the soil which form a symbiotic relationship with your plant roots. They deliver nutrients to your plant, and in return they eat the sugars that get secreted by your roots!

The “micro-herd” in the soil delivers nutrients directly to your plants. As long as you’re using decent water, you usually don’t need to worry about pH or other things that can disrupt nutrient absorption in regular soil.

However, when growing with Super Soil, it’s a good idea to avoid watering too much at a time, as extra runoff waterwill drain away some of the nutrinets. Try to give just enough water to saturate the soil with very little extra coming out the bottom. Since you won’t be adding more nutrients through the grow, you want to conserve what’s in the soil!

Nugbuckets is a famous organic soil grower! Check out his plants!

Organic Potting Mix

This is what kind of soil to get if you don’t have any “good” soil available, but want something that is known to work for growing cannabis.

Generally, anything labeled as an “organic potting mix” will work. This type of mix hasn’t been amended with chemical slow-release nutrients, which is one of the main things you want to avoid with soil for cannabis. I know it sounds like heresy, but even the Miracle-Gro version of “organic potting mix” will work okay, because unlike their original potting mix it doesn’t contain chemical nutrients (though it still has poor drainage and moisture retention – almost any other type of organic potting mix is better!).

Usually an organic potting mix does not have enough nutrients to last your plants for more than a few weeks, so it’s a good idea to always supplement with cannabis-friendly nutrients, especially in the flowering stage when your plant is making buds and needs lots of extra Phosphorus and Potassium.

Espona Organic Potting Mix is found in many stores in the US, and works for growing cannabis!

What to Watch Out For With Any Soil Mix At the Store

  • Look At and Touch It If You Can! You already have an idea what soil should look and feel like, but here’s a test: If you form the soil into a ball, it should stick together loosely, but it should also easily fall apart again if you squeeze it.
  • No “Time Release” Chemical Nutrients in the Soil – These types of soil slowly release nutrients over the course of months, which provides too much Nitrogen in the flowering stage and could possibly impair overall bud growth.
  • Soil Should Appear Dark and Rich – Pale, crumbly or sandy soil usually doesn’t have a lot of nutrient content that the plant roots can get to.
  • Soil Has Little White Rocks In It (Perlite), if you see white, almost fluffy rocks dispersed through the soil like popcorn, that is usually a good sign because it means this potting mix was intended to have good drainage.
  • Soil Isn’t “Heavy” – Cannabis grows best in soil with a light airy texture and great drainage, which may seem almost fluffy when it’s dry.
  • Example of “Good” Soil Ingredients – Composted forest humus, sandy loam, sphagnum peat moss, coco coir (sometimes labeled coco fiber), perlite, earthworm castings, bat guano, fish meal, crab meal, bone meal, blood meal, Azomite, pumice, kelp, dolomite lime, mycorrhizae and leonardite. That’s not everything, just examples of cannabis-friendly ingredients you see the most often
  • Examples of “Bad” Soil Ingredients – You don’t want to see wood or bark on the label if it doesn’t say it’s been composted first. Also if you see just the word “fertilizer” in the ingredients that’s often code for slow-release chemical nutrients, which you don’t want!

Try to get soil that looks like this!

I hope this soil tutorial helps you find the right soil for your cannabis setup!