Want to know more about best soil for cannabis? Check out our guide to get started with expert recommendations. 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 Growing cannabis outdoors offers many benefits. Firstly, it can be very affordable. You do not need to provide a structure like a greenhouse or high tunnel. In addition, artificial light is not necessary if you place it in the right spot in your yard, because your plants can benefit from the sun’s abundant and free energy. In addition, you do not necessarily have to provide costly soil for your plants outside. But for the best results, you want good marijuana soil that will help your plants grow healthy and happy. DripWorks is here to offer you a few simple tips for finding and creating the best soil for growing marijuana outdoors. Soil Types Four basic soil types exist: sand, clay, silt, and loam. Each has its pros and cons for gardening. Sand is easily permeable for root growth, for instance, but it does not hold on to water or fertilizer well. Clay is just the opposite. When it’s hot and dry, clay can become hard as a rock, making it difficult for roots to penetrate. Clay drains poorly and is hard to cultivate. On the plus side, it is rich in minerals and natural nutrients. Silt soils have lots of minerals and retain moisture well. Like clay, however, this type of soil can become compacted and hard in certain conditions. It can also form a crust, making it difficult for moisture and nutrients to reach plants’ roots. Loam for Growing Marijuana &amp; Other Crops Of these types, loam is by far the best soil mix for growing marijuana plants and many other types of crops. Loam is a mixture of clay, sand, and silt, bringing forth the best qualities of these disparate types of soil while minimizing their worst attributes. The optimal ratio for loam is 20% clay, 40% silt and 40% sand. Most folks think a pH of 6.0 is best for cannabis, with a range of 5.8 to 6.3 being acceptable. With a pH close to neutral, loam is typically in that zone or close to it. Test kits are available to measure your soil’s acidity, or you can take a sample to your friendly local extension agent. If your dirt does not have the proper acidity, soil amendments are available to lower or raise the pH level in your soil. Your local nursery, garden store or extension agent can make some suggestions. Loam is ideal for containers as well as for outdoor growing. Unfortunately, it is usually the most expensive soil to buy. But if you are interested in growing the best plants possible, it can pay big dividends in the long run. You can also build up your own loam soil by adding organic matter to it. If you have a compost bin, you can use the compost to improve your soil. This will be a time-consuming and ongoing process but with grit and persistence will pay off in the long run. Water, Light and Nutrients You will want to provide the proper amount of light and water to your plants, of course. A drip irrigation system can cut your water bills while improving the health of your plants. Kits are available that give you everything you need to get started. If you prefer, you can start from scratch and obtain separate components to put them all together. Just like humans, plants need the right nutrients. The most important ones for your cannabis plants are nitrogen (N), potassium (K) and phosphate (P). These make up the ratios you will typically see on fertilizer labels. The right balance is essential for healthy growth. Many pre-mixed marijuana fertilizers are available, making your job easier. But if you prefer, you can also formulate your own.
10 Best Soil for Cannabis in 2022 – Buying Guide & FAQs
Finding the right soil for cannabis planting is never easy. You never know what to get with such a sensitive plant.There are hundreds of soil products on the market. As a result, finding the right one can be difficult if you don’t know what to look for.
I researched the best soil for cannabis and found that FoxFarm Ocean Forest Soil Mix is the best overall option.
But depending on your preferences and grinding needs, you may want something different. If my #1 option is not for you, there are nine other soils on my list. Read on to find out which is the best soil for cannabis for you!
10 Best Soil for Cannabis Review
#1. FoxFarm Ocean Forest Potting Soil Mix
The FoxFarm Ocean Forest is a garden potting soil mix that is ideal to use for cannabis plants.
Each bag contains everything your cannabis plant needs for high growth and germination. It consists of a blend of earthworm castings, sea-going fish and crab meals, moss, bat guano, forest humus, and more. All of these mimic the properties of the highest quality naturally occurring soils.
The soil mix also has sandy loam and hints of clay and silt. With this particular composition, the soil mix allows proper water drainage. Make sure it reaches all sections of the soil to ensure adequate germination.
This is good soil because it has been pH adjusted such that its pH lies between 6.3 and 6.8. What this means is that the soil enables maximum uptake of fertilizer. This also encourages strong branching, leading to healthy and rapid growth.
The only problem you may run into is when you use this for autoflower cannabis strains. It’s not recommended for that kind of cannabis. But for all others, it’s a good choice.
- Diverse composition for effective growth.
- Features loam that guarantees proper germination in all sections.
- A mix of the highest-quality fertilizers.
- pH-adjusted for maximum fertilizer uptake.
- Encourages growth.
- Ideal for most types of cannabis.
- Not for autoflower cannabis strains.
#2. FoxFarm Happy Frog Organic Potting Soil
Fox Farm Happy Frog Organic Potting Soil is the ideal choice for bringing nutrition to your plants. It comes in a ready-to-use form straight out of the bag and it provides all the nutrients that your marijuana plant needs to thrive.
This is a bag of 51.4 dry quarts or 2 cubic feet of soil. The potting soil is meant for container planting, whether growing a Ficus or a geranium. It contains mycorrhizae which enhances water absorbance and reduces the need for fertilizer. Additionally, this soil contains humic acid. As a result, it increases nutrient uptake and accelerates cannabis seed germination. In other words, your cannabis plants will thrive in this soil.
And that’s not where it ends. The soil is ideal for both outdoor and indoor cannabis plants. The only catch is that the plant must be a container plant.
The best part is that this cannabis organic potting soil comes with a pair of Pearsons Protective Gloves included. Use these gloves to protect yourself when handling any harsh chemicals.
- Perfect for growing marijuana indoors and outdoors.
- Reduces the need for fertilizers.
- Enhances nutrient uptake.
- Ready-to-use out of the bag.
- Accelerates seed germination.
- Only for container plants.
#3. Coast Of Maine Stonington Blend Organic Growers Mix
The Coast of Maine Stonington Blend is an organic mix of soil and fertilizers. It is a complex soil made especially for promoting plant growth in pots and containers.
This soil has a diverse composition. It’s made from fish bone meal, endomycorrhizal fungus, worm castings, and perlite. It also contains dehydrated hen manure and Coco fiber that has been reinforced with lobster compost.
You may think that that’s just a random blend of the best fertilizers. However, it’s actually quite balanced. This blend provides the perfect balance between soil texture, drainage, and water retention. All of these factors stack up to promote the healthy growth of cannabis plants in containers.
What’s more, this blend is OMRI Listed. This means that it follows certain standards for organic fertilizers set by the OMRI.
One major issue with this soil, which you will notice right off the bat, is that it’s only for potted plants.
- A complex blend of fertilizers.
- Promotes healthy and rapid growth.
- Best for potted plants.
- Authentic organic fertilizer.
- A perfect balance of growth factors.
- Only for potted/container plants.
#4. Super Soil Autoflower Concentrate
If you’re on the hunt for the best natural soil for growing autoflower seeds, then this is for you. The Super Soil Autoflower Concentrate is a 5-pound bag of soil that promotes autoflower growth.
Just one 5-pound bag of the soil contains everything your cannabis plant will need from seed to harvest. This is living soil. This means that it contains fungi and microbes that encourage growth. And they symbiotically provide nutrition to the plant.
One thing to keep in mind is that this is a concentration. It should be mixed in a certain ratio with regular potting soil and shouldn’t be used on its own.
What sets this concentrate apart from the rest is that it’s an all-in-one blend. This is not only a top feed but also a soil amendment, compost tea, living soil, super soil, and potting soil.
Be warned, however, this is only for autoflower cannabis and other autoflower vegetables. It would still work for regular seeds, but not so well.
- Ideal for auto flower cannabis seeds.
- Promotes growth and provides nutrition.
- Also doubles as a super soil.
- Suffices the plant from seed to harvest.
- Includes fungi and microbes.
- Only for auto flower seeds.
#5. Purple Cow Indicanja 1 Cubic Foot Bag Organic Living Soil
The Purple Cow IndiCanja is an all-in-one ready-to-use organic soil. This soil is used by many professional farmers and horticulturists as well as hobbyist gardeners.
This is not living soil. It is a mix of compost from various plants containing all the essential nutrients for your plant.
But the manufacturers didn’t just mix in any random combination of compost and organic matter. Instead, the formula was scientifically designed to provide the maximum benefit. This formulation is water-only, meaning you just need to water it after you dump it in the pot.
Moreover, this compost-based solution has been grown and cultivated “cleanly”. This means that it won’t affect human health.
However, you may run into a fungus gnat problem with this soil due to its unique composition. Plus, it’s targeted toward cannabis plants that need to retain a lot of water. Hence, you must be careful not to overwater it.
- A mix of all essential nutrients your plant needs.
- Made with scientific input.
- Only need to water regularly.
- Cultivated cleanly.
- Retains a lot of water.
- May cause a gnat problem.
- Easy to overwater.
#6. Foxfarms 733266 Soil, Strawberry Fields Potting
FoxFarms Strawberry Fields Potting is a special potting soil. This has been designed to promote blooming and fruiting in plants. This potting soil is ideal for all types of flowering plants, including container gardens, house plants, and trees and shrubs.
This potting soil mix is available in many sizes, including a 1.5 cubic-foot bag. You can also get the 27 and 55 cubic-foot totes for larger gardens.
The FoxFarms Strawberry Fields potting soil is mainly coco coir-based. This is what allows it to retain less water and provide for better water drainage. It doesn’t contain a lot of peat, which means that it must be watered frequently.
It’s highly recommended for mature plants that need to flower, meaning it’ll be by your side when your cannabis is ready for harvesting. The soil pH is about 6-7, which is ideal for growing weed.
However, this soil is strictly for flowering plants. It’s not good for small plants as it simply won’t be as effective.
- Highly recommended for mature cannabis.
- Available in 3 sizes.
- Better water drainage.
- pH is perfect for growing cannabis.
- Ideal for flowering plants.
- Must be watered frequently.
- Not good for small plants.
#7. Roots Organics Original Potting Soil
The Roots Organics is a potting soil ideal for fast-growing plants that require a lot of care and nurturing. It’s the best choice for cannabis due to its high level of water retention.
To begin with, this mix is made from perlite and coco fiber, two of the best components for plant growth. Additionally, it features pumice, peat moss, and composted forest material. These ingredients lead to better water retention and reduce the need to water the plant.
Roots Organics also doubles as living soil. It contains living mycorrhizal fungi that enhance your plant’s ability to take up water through the roots.
What sets this organic potting soil aside from the others is that it comes ready to use right in the bag. Simply cut the top of the bag and plant your seeds. You can also dump the contents into a container garden.
You might, however, notice some fungus gnats, which are common with the composition this soil has.
- Promotes healthy plant growth.
- Enhances nutrient uptake ability.
- Comes ready-to-use in the bag.
- Retains a lot of water.
- Best for cannabis plants.
- May cause a fungus gnat problem.
#8. Brut Super Soil – 30 Lb
The Brut Super Soil is an organic soil concentrate designed for plants that require extra nutrients. It contains all the nutrients that your cannabis plant may be lacking.
For starters, it’s loaded with bacteria and enzymes that provide all the necessary nutrients your plant needs. On the organic side, it includes Brut worm castings, mycorrhizal fungi, composted cow manure, and kelp. These ingredients help enhance the nutrient uptake ability of your plant.
On the inorganic side, you get elements like magnesium, potassium, nitrogen, and phosphorus. These are required for healthy plant growth.
Keep in mind that this is only a soil concentrate. It is to be mixed with regular potting soil. What’s more, the Brut Super Soil contains peat moss which helps it retain more water. For cannabis plants, this is crucial as they require a lot of water.
What’s more, this soil concentrate is completely non-toxic and odor-free. So it won’t create an unpleasant and unhealthy environment in your garden.
- Enhances nutrient uptake.
- Provides all the essential elements.
- Perfect for cannabis and other plants.
- Retains a lot of water.
- Highly organic.
- Must be mixed with regular potting soil.
#9. Big Rootz All Purpose Potting Soil
Big Rootz is an all-purpose potting soil ideal for growing cannabis and other plants. It has been carefully formulated so that it offers maximum plant growth and helps in nutrient uptake.
This formulation is backed by research and increases plant vigor to lend it strength and sturdiness. This is a blend of peat and triple-washed coir. The peat-based formula indicates that it retains more water and doesn’t need to be watered very often. This is more than ideal for cannabis, a plant that needs a lot of water.
In addition to that, the Big Rootz All-Purpose Potting Soil contains worm castings and compost. Both of these provide essential nutrients such as Nitrogen to the roots of the plant.
This potting soil has been pH-adjusted to provide maximum results and increase the water uptake. However, you may run into a fungus gnat infestation.
- Backed by research.
- Retains a lot of water.
- Provides essential nutrients to roots.
- A balanced pH for maximum growth.
- Helps in water and nutrient uptake.
- May lead to a fungus gnat infestation.
#10. Mother Earth Terracraft Potting Soil
If you want potting soil that is recommended for all types of plants, then Mother Earth Terracraft is the way to go.
This soil consists of Sphagnum peat moss as well as processed forest fertilizer. These ingredients help the soil to retain more water than regular potting soil. In the long run, this means you waste less water and also less time watering your cannabis.
In addition to that, the Mother Earth Terracraft Potting Soil has moderate aeration which further helps it retain water. The blend is made from 8 ingredients, some of which include seabird and bat guano, and earthworm castings.
The Mother Earth Terracraft potting soil has a balanced pH with a traditional buffer. So adding new soils won’t change the pH much. This helps it retain more nutrients and helps the plant take up more water.
However, it’s not meant for autoflower cannabis.
- Retains more water.
- Doesn’t need to be watered frequently.
- Enhances nutrient uptake.
- Balanced pH with buffer.
- A unique blend of 8 ingredients.
- Not for autoflower cannabis.
Buying Guide of Best Soil for Cannabis
Stand-Alone Or Supplement-Based?
Stand-alone soils do not require to be mixed with other ingredients such as fertilizers or amendments. But supplement base soil can be adjusted with fertilizers and amendments accordingly.
Organic Or Inorganic?
Organic soils are best for cannabis as they are safe for the environment and many times include living organisms. Inorganic soils are cheaper and may be useful in some cases. Inorganic soils are usually better if you want to keep track of what and how much nutrients your plant is getting. They state explicitly what minerals they use and in what proportions.
Living Soil or Not?
Living soil contains microorganisms like bacteria and mycorrhizal fungi. So, living soil is ideal as it forms a symbiotic relationship with your plant. The bacteria and fungi allow your plant’s roots to take up more nutrients and water. However, they can give rise to fungus gnats and other insects.
The Number of Plants
Lastly, consider how many plants you have and buy the right size of potting soil accordingly.
General Features of The Best Soil for Cannabis
Nutrients And Amendments
The most commonly used amendments for growing cannabis are:
- Bat guano.
- Bone meal.
- Soft rock phosphate.
- Shrimp meal.
- Crab meal.
- Seabird guano.
- Fishbone meal.
In addition to that, cannabis plants require a lot of Potassium, Nitrogen, and Phosphorus.
Drainage & Water Retention
Most cannabis plants require a lot of water. Hence, you should look for soils that have a lot of water retention. These don’t need to be watered often.
The pH should stay between 6 and 7. You should look for soil that acts as a pH buffer, meaning it resists changes in its pH to some extent.
What is the Best Soil for Growing Cannabis?
Four basic types of soil can be used for marijuana growth. These include loam, silt, clay, and sand. And each of these has its pros and cons when it comes to gardening marijuana.
Sand is more root growth permeable, but it doesn’t hold fertilizer or water that well. Whereas clay is just the opposite to that. It can become pretty hard when dry and hot, and roots find it tough to penetrate it.
During this time, clay doesn’t drain very well and becomes hard to cultivate. However, it is rich in natural nutrients and minerals.
On the other hand, Silt has plenty of minerals and can also retain moisture pretty well. But it becomes too compacted and tough in various conditions.
It also tends to form a crust that makes it difficult for nutrients and water to get to the roots of marijuana plants.
Loam For Growing Cannabis & Other Crops
Loam is the best option of all four types for growing marijuana and many other types of crops. It is a mix of silt, clay, and sand, and it brings the best qualities of all types of soils while reducing their negative traits.
The pest composition is to go for 20 percent clay, 40 percent silt, and 40 percent sand. Most people think that the pH of 6.0 is ideally suitable for cannabis plants.
However, the acceptable range is between 5.8 to 6.3. as pH levels remain close to neutral, loam is the best option to consider when growing cannabis plants.
There are different test kits available for measuring acidity in your soil. You can also take a sample of your solid to your local extension agent.
If it doesn’t feature proper acidity levels, you can use various soil amendments to increase or decrease the pH levels. Your local extension agent, garden store, or nursery can help you make the correct AdSense according to your requirements.
Loam is the best option for containers, and you can use it for outdoor growing. However, it is also the most expensive soil available on the market.
Nevertheless, if you are interested in growing the best possible plants, quality loam can reward you long-term.
You can even make your loam mixture and add some organic matter. Then, if you have your separate compost bin, you can use it to improve your soil. It might take a lot of your time, but it can also produce magnificent results.
What is a good potting soil for cannabis?
The best potting soil for cannabis plants is loam, as it is for various other plants. It is a mix of silt (40 percent), clay (20 percent), and sand (40 percent). Its pH level remains between 5.8 to 6.3, and it can retain moisture and nutrients pretty well. This soil is also the most expensive type.
Can you plant cannabis in any soil?
You can plant cannabis in any soil, but there will be different implications, and each soil type has its pros and cons. Therefore, the best option to go for is loam soil, as it is a mix of all other soil types while amplifying their advantages and diminishing their drawbacks.
What kind of soil do Autoflowers need?
Autoflowering strains are similar to those photoperiod variations as they also prefer morse acidic soil slightly. You should go for the soil with pH levels between 6.2 to 6.5. But make sure that the soil is suitable based on its acidity.
How To Make Your Own Organic Super Soil?
You can make your organic super soil by using 8 large bags of coco fiber and mycorrhizae-rich cannabis soil. Add 25 to 50 pounds of earthworm castings to it. Now, take:
- 5 lbs. steamed bone meal.
- ¾ cups Epson salt.
- ½ cup sweet lime.
- 3 lbs. rock phosphate.
- 5 lbs. Bloom bat guano.
- 5 lbs. blood meal.
- ½ cup azomite.
- 2 tbsp powdered humic acid.
Add all these together and you have your very own organic super soil!
How To Grow Cannabis in Soil?
The first thing you gotta do is fill up ¾ of your container with potting soil. After that, gently place the plant and carefully add more soil to cover up the roots.
The rule of thumb here is to not fill it too compact. These roots tend to thrive from the nutrients within the cannabis soil and from the air pockets within the soil. the tiny roots will prevent the roots from rotting.
Therefore, it is important to refrain from pressing down too much on the soil mix. If you are using soil that already has its pH level adjusted, you can simply add water. Let the plant satisfy its thirst before you add more water to prevent overwatering symptoms.
All the soils on the review list are top quality, and Fox Farm Ocean Forest Soil Mix is the overall best soil for cannabis. Not only because it has sandy loam and hints of clay and silt, but also it has good water drainage and pH value.
Whichever option you choose, make sure it suits your plants’ needs and your budget.
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Hey there! My name is Umer, and I am a garden enthusiast. I discovered the power of the gardening in my 30s. Now five years later, that critical connection with nature continues to improve my life. My goal is to empower you with the advice you need to grow your home garden.
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.
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
- 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 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 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.
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!
The Best Soil for Growing Marijuana Outdoors
Growing cannabis outdoors offers many benefits. Firstly, it can be very affordable. You do not need to provide a structure like a greenhouse or high tunnel. In addition, artificial light is not necessary if you place it in the right spot in your yard, because your plants can benefit from the sun’s abundant and free energy.
In addition, you do not necessarily have to provide costly soil for your plants outside. But for the best results, you want good marijuana soil that will help your plants grow healthy and happy. DripWorks is here to offer you a few simple tips for finding and creating the best soil for growing marijuana outdoors.
Four basic soil types exist: sand, clay, silt, and loam. Each has its pros and cons for gardening.
Sand is easily permeable for root growth, for instance, but it does not hold on to water or fertilizer well.
Clay is just the opposite. When it’s hot and dry, clay can become hard as a rock, making it difficult for roots to penetrate. Clay drains poorly and is hard to cultivate. On the plus side, it is rich in minerals and natural nutrients.
Silt soils have lots of minerals and retain moisture well. Like clay, however, this type of soil can become compacted and hard in certain conditions. It can also form a crust, making it difficult for moisture and nutrients to reach plants’ roots.
Loam for Growing Marijuana & Other Crops
Of these types, loam is by far the best soil mix for growing marijuana plants and many other types of crops. Loam is a mixture of clay, sand, and silt, bringing forth the best qualities of these disparate types of soil while minimizing their worst attributes.
The optimal ratio for loam is 20% clay, 40% silt and 40% sand. Most folks think a pH of 6.0 is best for cannabis, with a range of 5.8 to 6.3 being acceptable. With a pH close to neutral, loam is typically in that zone or close to it.
Test kits are available to measure your soil’s acidity, or you can take a sample to your friendly local extension agent. If your dirt does not have the proper acidity, soil amendments are available to lower or raise the pH level in your soil. Your local nursery, garden store or extension agent can make some suggestions.
Loam is ideal for containers as well as for outdoor growing. Unfortunately, it is usually the most expensive soil to buy. But if you are interested in growing the best plants possible, it can pay big dividends in the long run.
You can also build up your own loam soil by adding organic matter to it. If you have a compost bin, you can use the compost to improve your soil. This will be a time-consuming and ongoing process but with grit and persistence will pay off in the long run.
Water, Light and Nutrients
You will want to provide the proper amount of light and water to your plants, of course. A drip irrigation system can cut your water bills while improving the health of your plants. Kits are available that give you everything you need to get started. If you prefer, you can start from scratch and obtain separate components to put them all together.
Just like humans, plants need the right nutrients. The most important ones for your cannabis plants are nitrogen (N), potassium (K) and phosphate (P). These make up the ratios you will typically see on fertilizer labels.
The right balance is essential for healthy growth. Many pre-mixed marijuana fertilizers are available, making your job easier. But if you prefer, you can also formulate your own.