It is important to begin growing cannabis with the right soil. Otherwise, your marijuana plants may not be healthy and productive. Want to know more about best soil for cannabis? Check out our guide to get started with expert recommendations. Additives that will help you improve soil quality, resulting in better growth cannabis. What to consider when it comes to growing weed in organic soil.
What is the Best Soil for Cannabis, Weed, and Marijuana?
Everyone has heard about people just growing cannabis in their backyard or out in the woods. Yet as with any crop, growing cannabis in regular soil really is not ideal. If you have ever grown fruits or vegetables, you know that different types of plants need different nutritional content. Even growing something as simple as grass requires specific soil acidity levels and fertilizers.
In this article, we will cover why growing cannabis in regular soil is not ideal, what the best type of soil really is, and tips for getting the best grow.
Why Regular Soil Is Not Ideal for Growing Marijuana?
When starting a traditional garden, many gardeners have to spend months enriching their soil. But even enriching soil is not always ideal for growing marijuana. If you have been to a garden center, you may have noticed that there are different blends of soil for things like succulents, flowers, vegetables, and fruits. Different types of plants need different levels of nutrients. Soils tend to differ in five major ways: drainage, nutrients, texture, pH level, and water retention.
What is the Best Soil for Cannabis?
There are dozens upon dozens of different brands of soil. What you will need to look for is soil that has the right blend of attributes for your marijuana plants. Here is what you need to know:
- Drainage. Some plants will rot readily if their roots are allowed to remain moist. High drainage soils are frequently used for plants such as succulents, in order to make sure that their roots dry out quickly. The addition of things like “perlite” improve drainage. Cannabis does not need high drainage. Moderate to low drainage is fine.
- Water retention. This controls how long water will be retained in the soil. If you have soil with low water retention, you will need to water your plants more frequently. Cannabis plants like water, which means you want soil with high water retention. Soils that include peat moss are a good choice, as this keeps the soil moist.
- Nutrients. If you are growing cannabis, it is very likely that you are going to be adding a nutrient base of fertilizer to your soil regardless. That means that in terms of nutrients, you really just want a high quality, general purpose soil. Many prefer organic soils, to ensure that the cannabis that they receive will be organic. Organic soils do not have added chemicals that could be harmful.
- Texture. The texture of your soil can range from a coarse soil to a very silt-like soil. In reality, this does not matter so much for cannabis: you can choose a soil texture that makes the most sense in your setup. If you are growing in pots, you may want a potting soil that holds together better. If you are planting outside in raised garden beds, you may want a heavier, more clay-filled soil. pH level. This is the acidity or basicness of the soil. Cannabis tends to prefer its environment to be slightly acidic. In general, the best soil for cannabis is going to be between 6 to 6.8 pH.
These are all the attributes of the soil itself. You can alter these attributes through the use of fertilizers. For instance, frequently you may add nutrients such as nitrogen to the soil through a fertilizer. Because of this, getting the right blend for your marijuana plants is actually a bit complex. You may need to fine-tune your soil and fertilizer combination over time, and if there are any issues you see in your plants (such as wilting) they may be directly related to soil, drainage, light, or any other number of factors. Consider taking the guesswork out of having to mix fertilizers or nutrients by utilizing a fully amended living soil, such as SoHum Living Soil®.
Tips for Growing in Higher Quality Soil
Contact us today, and you will be on your way to high-quality marijuana plants.
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.
Best Soil For Cannabis – What is Good Soil For Growing Weed?
Signs of good and bad soil quality, other additives that help to improve soil quality and what to consider when it comes to planting this year.
- 1. The benefits of organic soil
- 1. a. Organic soil additives
- 2. Other additives that improve soil quality
- 2. a. Coco
- 2. b. Biochar
- 2. c. Perlite
- 2. d. Vermiculite
- 3. Signs of good soil
- 4. Signs of bad soil
- 5. How to make your own soil
- 5. a. Best nutrients for soil
- 5. b. Cheap mix for diy soil
- 5. c. Best soil for beginners
- 5. d. Ph too high or ph too low
- 5. e. Best soil for marijuana
- 6. In conclusion
When growing autoflowering Cannabis plants, it is very important to keep them supplied with nutrients in the form of hard foods, or liquid feeds. The best soil for autoflowers will depend on your environment, fertilizers, and ability to control the pH, so keep this in mind if this is your first grow cycle, knowing the best option in your case can really set you on your way to bountiful harvests.
So if you’re wondering what soil is best for growing weed, below we’ll explain what to know, the signs of good and bad soil quality, as well as what you should consider when it comes to planting this year.
1. The Benefits of Organic Soil
Soil for autoflowers or for any other type of cannabis plant consists of organic material that is in a permanent state of decomposition. Teaming with beneficial microorganisms that are responsible for converting nutrients to the plant’s roots, living soil is Mother Nature’s way of allowing autoflowering plants to work in a symbiotic relationship. As the tiny microorganisms decomposing the organic matter, they make the nutrients available for the roots, which are now able to access all the available nutrients and minerals found within the soil web. Once this symbiosis occurs, then the only real requirement is for the soil to be adequately watered. This is basically the most simple form of organic growing that is perfect for those new to growing, it requires very little maintenance, and labor, as well as allowing the grower to work with a slow buffering organic process, so if you were wondering what is the best soil for growing weed, read along.
Organic Soil Additives
Using organic soil additives or amendments will help increase the number of beneficial microorganisms, improve moisture retention, and help you control the health of your soil. In general, you should be looking at adding these amendments before planting. They will help you create the best organic environment for the root system to thrive, which will result in amazing growth and the full terpene profile maturing.
Bat guano is one of the most widely used additives in cannabis cultivation. It is a fast-acting, highly bio-available organic fertilizer with high rates of nitrogen and phosphorus making it perfect for the vegetative growth stage. It also helps improve the drainage and oxygenation of the soil mix, helps boost the natural immunity against pests, fungal infestations, and disease, and can ensure the best possible terpene production (although there is little scientific evidence to back up this claim).
Be careful with the amount you introduce to the substrate, as bat guano is pretty strong stuff. A little goes a very long way.
It can be used in both its fresh or dry form and is typically sourced in either powder or pellet form. It can be used in many ways other than as a direct additive to the soil. Many cultivators used bat guano as a fertilizing tea, or as a foliar spray. It can also be used as a top dressing by sprinkling it directly around the base of the plant and then watered in. To make a super effective bat guano tea all you need is 15 grams of bat guano, 1 liter of lukewarm water, and an air pump. Mix the guano and the water together well, and make sure the water is only lukewarm. Hot water will kill the microbial life that you are trying to introduce to the mix. Give it all a good mix, throw the pump in and let it aerate for at least 24 hours. This tea can be supplied twice a week throughout the entire lifecycle of the crop.
Worm casting, or worm poo, is literally the most bio-available organic fertilizer with ridiculous levels of both nutrients and minerals. Also referred to as vermicast, this top-shelf additive is perfect for any organic cannabis garden. It not only provides long-lasting, slow-release nutrition to the crop but also increases the aeration of the soil and provides excellent drainage.
You can swap out any potting mix you may use for 100% worm castings, and you do not have to worry about nutrient burn issues at all. Creating your own worm farm at home is super simple and can provide you with an unlimited supply of castings, ready to use at a moments notice, and provide your crop with almost everything it needs to provide you with bumper harvests.
Cow manure makes a perfect slow-release fertilizer. It usually contains a very well-balanced mix of the three main macronutrients that plants need for healthy and vigorous growth, plus manure works as a very efficient soil conditioner and helps increase the amount of microbial life in the soil, while also boosting moisture retention. Keep in mind that some manures may have herbicide contamination, so always check the packaging to ensure it is fully organic. If you live near a farm and can get it directly from the source then even better!
You want to mix the manure in before planting, and make sure there is no heavy rain forecast for the next week or so to prevent the chances of all the goodness being washed away. Chicken manure, on the other hand, is considered to be “hot” manure, meaning it can easily burn the plants if not allowed to sit and mature. In general, we do not recommend using chicken manure for your cannabis crop.
Bone Meal and Blood Meal
Bone meal is made from the ground-up bones of beef cattle and is a fantastic source of both phosphorus and calcium. It is used pretty extensively with outdoor cannabis cultivation but is not recommended for indoor growers. It does come with quite an acidic pH level which needs to be balanced, so keep that in mind. Blood meal is made from, you guessed it, the blood of beef cattle. It is very rich in bio-available nitrogen, but can also easily burn the plants if overused.
It too comes with quite an acidic pH level which must be balanced. Both of these additives can attract the attention of wild animals which can easily wreck the crop, so make sure any plants that use these amendments are well fenced off. It goes without saying that these additives are anything but vegan, so if that is important for you then choose other fertilizing options.
Kelp meal is one of the most desirable additives for cannabis crops, as it is packed full of over 65 different essential elements and minerals, and also contains a very healthy dose of potassium. Many growers are of the thinking that kelp meal provides a huge boost to the flavor and color range of cannabis, which we agree with.
Every single cannabis crop, no matter the method or techniques applied, should have mycorrhizal fungi added. This type of fungi plays a very important role in helping the plant feed on the nutrients by turning them into a more bio-available source. They also help protect the root system from attack by pests, disease, and harmful fungi.
2. Other Additives That Improve Soil Quality
One of the downsides to using soil found in the ground is that it can be very dense once watered. Restricting root growth during the early stages of a Cannabis plant’s life is never advised, so adding other substrates into your living soil can be very advantageous.
By simply adding a 25-50% ratio of coco coir to your cannabis soil, the quality of the mix will become very airy and lightweight. Adding coco will enhance the air pockets present, the wicking action of the medium, as well as encourage a mass expansion in the rhizosphere. Coco is very user-friendly and is well associated with large yields. The best thing about adding coco is the fact it is an inert growing medium, so does not have any nutritional value in terms of Nitrogen, Phosphorus, or Potassium, including trace elements.
- Increases aeration and holds water better: Due to its characteristics, coco fiber can increase aeration in the soil and can absorb up to 10x its own weight in water, making it vital for growers living in dry weather.
- Cheap: Coco fiber is relatively cheap and comes in various forms. You can find it compressed into a brick or already washed and ready to use out the bag, the price may change a bit depending on your preference but it won’t be absurdly expensive.
- Easy to use: Coco is a sterile medium so fungus and other bugs avoid it, making it perfect for growing cannabis. Also, because of its neutral pH, you can use it with soil amendments without worrying.
- Sterile: Because this type of medium is sterile, it won’t contain any of the nutrients your plant needs, even though you can mix it with soil or even amend it, you will have to provide all the nutrients your plant needs if you’re only using coco.
- Needs to be washed: The quality can vary from brand to brand, so depending on the brand, you will have to soak it and wash it a couple of times to remove impurities before using it.
- Hard to find good quality: Even though it’s relatively easy to find coco coir, it can be hard to find good quality coco fiber. This doesn’t mean you can’t use it but you will have to wash it thoroughly and experiment with a couple of brands before you’re 100% satisfied.
An incredible organic addictive that has amazing water-holding capabilities, an enormous surface area, and is a source of pure carbon. Biochar is made by heating wood to such temperatures that the end result is a tiny, charcoal-black crystalline substrate. Due to the fact it is 100% carbon and has a shelf life of thousands of years, organic farmers use biochar with their soil to improve water retention allowing for less watering times, feeding the beneficial microorganisms a rich source of carbon, and helping save the planet.
Organic additives like Coco Coir and Biochar can drastically improve the quality of your soil, improve water retention and not to mention help you to save the planet.
- Increases soil fertility: Biochar can boost soil fertility when used in combination with amended soil because it prevents nutrients from leaking out and provides carbon which increases the availability of nutrients in the medium.
- Holds nutrients and moisture: Thanks to its porous surface, biochar can absorb a lot of water and draws in minerals which are essential for plant development.
- Reduces the need for fertilizers: Because biochar is carbon-rich, it accelerates the decomposition of organic matter which results in more nutrients being available in the medium, a perfect choice for organic growers.
- Can affect yields: Due to the porous characteristic, biochar can absorb too much water and nutrients when used in excess and can end up stressing your autoflowering plants which will show signs of deficiencies.
- Can be contaminated: The quality of biochar is influenced by the material it is made of, so it can come contaminated with heavy metals or harmful compounds that are bad for your autoflowering plants.
- Harmful to humans: If not dealt with caution, you can end up breathing ash which is a concern if exposed to daily, also, it can irritate you if it comes in contact with your eyes or skin for a long period of time.
Perlite is usually used in soil mixes to increase aeration and improve the soil’s texture, by using perlite in the proper amounts you will not only improve drainage but also avoid compaction, making it a better medium for the roots to grow in. Usually, perlite is used in combination with coco fiber and soil to provide the best medium for the roots, while perlite improves aeration, coco fiber absorbs water, balancing those two elements in the best ratio possible.
Perlite can also be used to plant clones in, when you place your cuttings in perlite, the roots usually grow stronger and faster because they need oxygen to thrive and perlite helps provide it.
- Increased aeration: Perlite creates small air pockets in the soil so if used properly, it can improve the growth rate.
- Sterile medium: Because it’s a sterile medium, perlite won’t affect the pH of your medium or increase the amount of minerals in it.
- Avoids soil compaction: Perlite needs to be thoroughly mixed in the soil before using, this will create several air pockets that make the soil fluffier, avoiding compaction.
- Can dry the medium faster: You will need to check your autoflowering plants closely because with more oxygen in the soil you will have to water more often.
- Needs to be washed first: If the brand you’re using does not pre-wash the perlite, it may come with a fine dust that can be harmful if inhaled so we recommend washing your perlite before using.
- Needs to be watered more often: Because the medium will dry faster, you will need to water more and this means you will need to check on your autoflowering plants at least 2 times per day to make sure everything goes accordingly.
Vermiculite can be used to improve the quality of your soil, just like perlite, vermiculite has several qualities that will make your autoflowering plants grow better and faster. This mineral helps aerate the soil, holds water and nutrients while not being toxic or changing the pH.
If your soil is compact or does not drain water properly, you can add vermiculite to provide the roots a better medium to grow in, just make sure you’re using the proper ratio because too much can hold a lot of nutrients and water and end up harming your autoflowering plants.
- Neutral pH: Because it’s a sterile medium, vermiculite will not alter your soil’s pH so there’s no need to worry about checking the runoff every day.
- Can prevent mold: When used in the proper ratio, vermiculite will absorb the excess water, preventing mold and fungus in the soil.
- Improves soil quality: Just like perlite, vermiculite improves the soil’s texture and makes it fluffier, preventing soil compaction.
- Can be expensive: Depending on where you live, vermiculite can be relatively hard to find and a bit expensive because it’s not usually found in regular grow shops.
- Can affect autoflowering plants if used in excess: Because perlite holds nutrients and water, using it in excess can ultimately result in overwatering and overfeeding.
- It’s said to be harmful: When buying low-quality vermiculite, it can contain asbestos and can cause lung problems. Inhaling these tiny fibers can cause asbestosis, mesothelioma, and lung cancer if exposed for a long time so it’s essential to buy the best quality possible and wash it before using it.
3. Signs of Good Soil
Due to the process in which soil is naturally produced, there are a few factors to consider if you are going to prepare your own. If buying soil from a well-known brand, or your local garden center’s cheap and cheerful products then there are some things to consider.
- Check the packaging to see the nutritional value of the soil. A good brand will take the time to display a soil nutrient analysis displaying-N-P-K values, amount of perlite, vermiculite, compost, trace elements, and the bacterial and fungi count present.
- Worms aerate the soil as they crawl through eating up organic matter. If you see your soil full of worms then do not worry. Not only will these little helpers aerate the soil but will release beneficial bacteria from their gut as they do.
- Good store-bought soil will have perlite or coco added allowing for the ideal balance of air to water retention. Avoid soils that do not have any perlite unless you are purposely buying pure worm castings.
4. Signs of Bad Soil
- Bad soil will have an unpleasant smell which is a red flag bad bacteria are present, causing the medium to be in an unfavorable acidic state.
- Drainage will be poor, causing the soil to become dense and heavy. This weight can restrict root growth and slow plant development down dramatically. The ratio of water retention, drainage, and wicking capabilities will all be out of balance.
5. How to make your own soil
To make your own soil mix you need to have in mind the conditions that you will have during your growing cycle, things like temperature and humidity may have an influence in the best mix, so make sure you know the conditions before mixing your soil.
Best nutrients for soil
We recommend always using organic nutrients when growing in soil because soil it’s organic matter and contains microorganisms that can greatly benefit your autoflowering plants if taken care of properly. We cannot recommend a certain brand or organic nutrients line but as long as you’re using high-quality organic nutrients and use them appropriately, you’ll be fine. Just make sure the nutrients are 100% organic and keep an eye on the pH level because a drastic increase or decrease can ultimately kill the microorganisms present in your soil.
Benefits of good quality soil and what to keep in mind when you’re looking for the best soil for cannabis possible.
Cheap mix for DIY soil
Even though you can find organic nutrients in your local grow shops, they can be quite expensive so if you’re on a budget there are good alternatives that are relatively cheap.
There are several other methods to make your own organic nutrients such as KNF and Bokashi.
Depending on the space you have available, you can try composting or vermicomposting, these methods allow you to make your own tailored organic soil that will provide everything you need without spending too much.
Best soil for beginners
If you’re a beginner grower and don’t know exactly how things work, here is a general soil recipe that will work fantastically in almost all types of weathers, just remember that as time passes and you get more experienced, it’s ideal you adjust it to your specific needs.
General DIY soil recipe mix:
- 80% organic soil
- 10% perlite
- 10% coco fiber
Remember that you can and should tweak it to your needs, but as long as you maintain a similar ratio your autoflowering plants will grow exceptionally.
PH too high or pH too low
If the pH of your medium is too high or too low, you should check the nutrient solution you’re feeding, have in mind that most additives are sterile and neutral so if you’re experiencing pH problems you should check the water source and nutrient solution.
Best soil for marijuana
The best soil mix for autoflowers or best marijuana soil, in general, will depend on the weather you have throughout your grow cycle, by following the table you can easily choose the one that better suits you.
|Advantages of soil additives when growing autoflowering plants|
|Additive||When to use||Advantages|
|Coco fiber||Use in dry environments or to improve soil quality.||Holds water and helps avoid soil compaction.|
|Biochar||Use in dry climates or when growing in organic soil.||Improve water retention and helps decompose nutrients faster.|
|Perlite||Used to help aerate the soil in humid environments.||Helps dry the soil faster and increases aeration.|
|Vermiculite||Used in dry environments, helps keep the soil moist.||Improves soil quality and helps keep it moist.|
As a general rule, you should always use 70-80% of organic soil mixed with the additive of your choice, always have in mind to use additives with different properties, for example, vermiculite shouldn’t be used with coco fiber because both absorb a lot of water and can cause overwatering.
- 70% organic soil
- 15% perlite
- 15% coco fiber or 15% biochar or 15% vermiculite
For the best soil for autoflower plants, we recommend using 70-80% organic soil mixed with 15% perlite and 15% coco fiber, or substituting coco for vermiculite or biochar, always respecting their properties to avoid having oxygen or water in excess. Remember that for the best growing medium for autoflowers, you should be on the lookout for the tips your plants give you and adjust the ratio if needed.
6. In conclusion
There isn’t a best soil for weed, in general, having all of the nutrients covered is one-half of a top-quality soil for marijuana, however, it should also have the ideal ratio of drainage, air pockets, and wicking action so we recommend looking into super soil for autoflowers.
Once you have found the ultimate balance, you can now confidently re-use your organic growing medium for multiple crops with the understanding the more time the living soil food web has to develop, the greater the results in terms of plant performance and yields.