(Last Updated: April, 2023)
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7 Best Soils for Growing Cannabis
As your growing medium, the nutrient balance of your soil shapes how your cannabis plants grow, how abundantly they flower, and the number of buds they yield. Although the marijuana plant grows like a literal weed, growing it optimally in a way that enables it to produce trichome-rich flowers and express its best traits demands good care, attention to detail, and most importantly, the best soil for growing weed outdoors or in stealthy grow boxes for your home.
That's where pre-made cannabis potting soil comes in. Potting soils allow beginners and pros alike to grow marijuana plants quickly and efficiently. You're sure to find everything your weed plants require in these soil mixes like beneficial microbes, earthworm castings, macronutrients, bacteria, vitamins, and more.
Plus, cannabis-specific soil mixes offer a more natural form of plant growth than the hyper-accelerated growth of aeroponics or hydroponics. We've gone through various soil brands and mixes to help you find the best way to grow cannabis in soil and the best soil for maximum production.
Whether you need an all-in-one soil mix or a viable organic soil, we've got your marijuana plants covered. Without further ado, here's our list of the seven best soils for growing cannabis.
How Do You Choose Soil for Growing Cannabis Plants?
Contrary to popular belief, not every soil is fit for growing cannabis plants, and not all weed plants need the same type of soil. Remember, picking the best cannabis soil depends on;
- Type of marijuana plants you're growing
- Climate
- Whether you're growing weed outdoors or in grow tent setups in the house
In addition to the factors mentioned above, you'll find common characteristics among all cannabis soils. They include;
Drainage ability
Cannabis soil should typically have excellent drainage. Waterlogged soil causes poor root development and subsequent slow growth. If you notice soil surface water forming in pools while watering your marijuana plants, your cannabis soil may have poor drainage.
Texture
Cannabis plants don't perform well in heavily compacted soils. The best soil mix for marijuana plants tends to be light, airy, and loose in texture. Besides promoting root development, a light texture ensures more oxygen reaches your plant roots for optimum growth. You can combine your cannabis soil with porous fabric root sacks or air-pots for maximum growth and health.
Water retention
Although the best cannabis soil for growing weed should have excellent drainage qualities, it should also retain moisture for your plant roots to absorb. In simple terms, your cannabis soil should come with a perfect balance of drainage and water retention.
pH Value
pH value is a chemical scale that shows how alkaline or acidic your cannabis soil is. This is essential as the best soil for growing cannabis plants only performs within a small pH range. That said, ensure your soil for cannabis has a pH value of about six. Some cannabis growers often wonder how they can test their soil pH for cannabis. Well, it's pretty simple. You can purchase specialist kits that are designed to measure cannabis soil pH.
Nutrients
Nutrients play a pivotal role in cannabis plant growth. Luckily, nearly all cannabis soils you can purchase already feature them. But the problem is, their nutrient level becomes depleted with time, requiring you to use bloom nutrients as your young cannabis plants start to flower. These nutrients will often last for about 3-4 weeks.
If you're growing cannabis plants your indoor growing tents without additional nutrients, your soil must contain organic substances like forest humus, worm castings, compost and guano. With the help of beneficial microorganisms in the soil, these organic substances will turn into essential nutrients.
Some cannabis growers don't like feeding a bloom nutrient to their cannabis plants. Instead, they try making the right soil (best organic soil) for weed which can feed the plants for their entire growth.
Related content: Grow box vs grow tent
More About FoxFarm Happy Frog Potting Soil
FoxFarm Happy Frog is the best potting soil for young cannabis plants specially designed for outdoor and indoor cultivation. If you're beginning your cannabis cultivation journey from the ground up, this potting soil is an excellent option to nurture your seeds and seedlings.
Its nutrient source stems from earthworm castings, composted forest humus, and bat guano. There's more than enough nutrients that can last an entire weed plant cycle, from preparing the seedbeds to harvesting. Happy frog potting soil also boasts other essential features like pH level.
Pros:
- Comes loaded with soil microbes and worm castings
- Ideal soil composition that doesn't drain too fast
- Perfect for seedlings to mature into the cannabis plant
- Insect free
Cons:
- Doesn't offer enough P & K for the flowering phase
Related Products | |
|---|---|
Fox Farm Liquid Nutrient Trio Soil  | FoxFarm GLCMBX0006  |
The Andersons BioChar DG Organic Soil  | Nature's Care Organic Potting  |
More About Nature's Living Soil Organic Super Soil
From planting, to pruning cannabis plants and harvesting buds, Nature's Living Soil has got your back. If you're digging through the internet on growing weed, you might have heard of the term super soil. Coined by the legendary seed producer, Subcool, super soil describes a neutral organic plant soil base enhanced with nutrients and microorganisms.
Using super soil removes the urgency for liquid nutrients as your weed grows. Nature's Living Soil Organic Super Soil features all the nutrients your plant deserves with only regular watering. Their concentrates have specifically selected and cultured microbes that enhance symbiotic relationships with your plant's root system to feed your plant and protect it.
This organic soil mix offers excellent yields and excellent flavors and potencies, boosting your plant's genetic potential. Plus, it's effortless to use, making it one of the favorite options for first-timers and experienced growers alike.
Pros:
- Premium soil blend
- Comes with beneficial microorganisms
- Natural and organic soil option
- Ideal for both professionals and beginner articles
Cons:
- Costly
Related Products | |
|---|---|
Fox Farm Liquid Nutrient Trio Soil | FoxFarm GLCMBX0006 |
The Andersons BioChar DG Organic Soil | Nature's Care Organic Potting |
More About Fox Farms Ocean Potting Soil Mix
Fox Farm Ocean Forest is undoubtedly the best organic potting soil to grow plants lush and healthy. It's a tried and tested soil mix that's easy to use for all the phases of plant growth. A massive benefit for using Ocean Forest is that it's ready to use the moment you unpack it for outdoor and indoor plants of every type.
Unlike ordinary soil, this organic potting soil generates superior quality and produce tasty buds. You can either use it as mulch for your farm if you're growing weed outdoors or combine it with native soil. You also have the opportunity to grow your cannabis plants in a container or a pot, not to mention other potted plants such as herbs, plants and veggies.
The Fox Farms Ocean consist of natural minerals such as earthworm castings composted, fish and crab meal, sphagnum peat moss, forest humus, and much more. Thanks to the nutrient-rich elements, Fox Farm Ocean organic potting soil can protect your plant roots and help them resist pests and diseases.
These organic soil ingredients bring forth great nutritional value to your marijuana plants without causing a significant impact on the environment, humans, or even pets. Adding them to your potting soil in the container or pot holds the water in your soil much longer. So, consider doing less watering per day.
Pros:
- pH adjusted
- Resist pest and diseases
- Better crop yield
- No pesticides
Cons:
- Not enough perlite for aeration
Related Products | |
|---|---|
Fox Farm Liquid Nutrient Trio Soil | FoxFarm GLCMBX0006 |
The Andersons BioChar DG Organic Soil | Nature's Care Organic Potting |
More About Big Rootz All Purpose Potting Soil
As an all-purpose potting soil blend, Big Rootz has all the inputs and nutrients needed to enable your plant to maintain its healthiness through its entire growth life and into bloom. Big Rootz is well-known for award-winning potting soils, and this model is no exception. You can use it outdoors and indoors. It comes thoroughly mixed, ready to use right out of the bag.
This means you won't waste time mixing ingredients yourself, making it a perfect option for first-time growers, too. With Big Rootz All Purpose Potting Soil, you can always rest assured that you're using a clean and safe product because they test each batch for heavy metals, pesticides, and GMO's.
That way, they're able to minimize or prevent inconsistency in their project. This super potting soil features an excellent grade of natural ingredients that can make up a base. Here, you may want to use peat moss, which can retain about 20 times its weight. In addition, peat moss assists in improving water retention and hydrates marijuana as necessary.
Pros:
- Contains water-retaining peat
- Formulated with mycorrhizae fungi for enhanced root growth
- Easy to use
- Features pre-washed coco coir to minimize nutrient lockout
Cons:
- High chances of pests in the soil
Related Products | |
|---|---|
Fox Farm Liquid Nutrient Trio Soil | FoxFarm GLCMBX0006 |
The Andersons BioChar DG Organic Soil | Nature's Care Organic Potting |
More About Sungro Black Gold All-Organic Potting Mix Plus
Generally, the best soil for growing marijuana doesn't have to be cannabis-specific. Sometimes, all you need is the right organic potting soil, and Sungro Black is a viable alternative. It features all the vital traits of the perfect soil for growing weed. And you won't even have to break the bank to own it. Its loamy mixture has an optimal blend of perlite and pumice for microorganism development and hydration.
Besides, its balanced nutrient blend is suitable for young marijuana plants. Every ingredient in Sungro Black Gold is organic and fit for a broad range of environments, ranging from indoor hanging baskets to patio containers. Black Gold is a high-performance base soil for marijuana that's sure to give you the high yields you crave.
Pros:
- High- performance base soil versatile
Cons:
- Gnat problems
Related Products | |
|---|---|
Fox Farm Liquid Nutrient Trio Soil | FoxFarm GLCMBX0006 |
The Andersons BioChar DG Organic Soil | Nature's Care Organic Potting |
More About Mother Earth Coco plus Perlite Mix
As a reputable US-based company, Mother Earth offers a wide range of top-rated amendments and growing media for all purposes, and the Coco plus Perlite Mix is no exception. It has been designed as both an outdoor and indoor alternative to potting soil that minimizes the risk of worrying about overwatering.
As the name suggests, one of the vital ingredients used to create Mother Earth Coco plus Perlite Mix is coco coir. Coco coir allows nutrients to be absorbed easily by the plant roots, thus improving aeration and overall drainage. Although it's relatively recent, Coco plus Perlite Mix is increasingly becoming popular as many growers are now using it instead of peat moss.
Pros:
- Last longer in potting containers
- Contains enough nutrients
- Offers powerful drainage
- Appropriate for both outdoor and indoor
Cons:
- Can invite fungal gnats
Related Products | |
|---|---|
Fox Farm Liquid Nutrient Trio Soil | FoxFarm GLCMBX0006 |
The Andersons BioChar DG Organic Soil | Nature's Care Organic Potting |
More About Coast of Maine Stonington Blend Grower's Mix
Coast of Maine Stonington Blend Grower's Mix is a complex super soil designed explicitly for top-performance container growing. This organic soil incorporates kelp meal, alfalfa meal, mycorrhizae fungi, coco coir, worm castings, and fishbone. This complex super soil was entirely designed with marijuana plants in mind. Formulated with amendments and rich in nutrients, Stonington Blend boosts budding, blooming, and plant root development. Plus, it offers the best balance between soil texture, water retention, aeration, and drainage in consistent cannabis growing medium.
Pros:
- No need to adjust the pH
- You don't require supplements
- Top-notch organic and natural soil blend
Cons:
- Doesn't have perlite that fosters proper drainage
Related Products | |
|---|---|
Fox Farm Liquid Nutrient Trio Soil | FoxFarm GLCMBX0006 |
The Andersons BioChar DG Organic Soil | Nature's Care Organic Potting |
Characteristics of the Best Soil for Cannabis
For cannabis growers who tend to use store-bought potting soil mixes, they're already optimally tuned, perfect for growing cannabis plants. However, it's a different story if you grow cannabis organically, with soil rich in organic matter. Natural soil typically comes in four varieties: clay, silty, sandy, and loam soil.
Clay
Clay soil features fine mineral particles. In addition to being high in pH, it's rich in minerals and nutrients, making it an ideal option to add to organic grows. However, this type of soil is heavy, hence not easy to work with. Plus, it has good water retention but poor drainage.
Silty
This is a medium-coarse type of soil that comes packed with minerals and organic particles. Although it has good water retention, its drainage is a bit adequate. Unlike clay soil, working with silty soil is very easy. The organic matter and minerals within makes silty soil rank among the most fertile soil types.
Sandy
Sandy soil is course and has good drainage. However, it has poor water retention. So, when watering your cannabis plants, essential nutrients like nitrogen will quickly get washed away. But some cannabis growers still use it as it's easy to work with.
Loamy
Loamy soil features the traits of clay, silt, and sand soils with added organic soil compounds. It offers optimal drainage and water retention, thus making it one of the best soils for growing weed. What's more, it's rich in oxygen and nutrients. But remember, this soil type can be a bit expensive.
Soil Amendments for Healthy Growth
If you're growing weed in natural soil, the outcome might not be perfect, especially during the first stages of growth. For instance, your soil may have poor drainage or less optimal soil texture. Fortunately, you can improve just about any soil for growing weed by adding amendments.
Some of the common soil amendments include;
Perlite
This is the most widely used cannabis soil amendment. Perlite features light, bright-white rocks that can help improve your soil's drainage and airiness. Add about 10-15% of perlite to amend your soil for cannabis with it. Otherwise, adding more may make your soil too light, leaving room for nutrients to leach out.
Clay Pebbles
Most cannabis growers tend to include clay pebbles in their hydroponic setup. But have you ever thought of using them to improve soil structure? Adding pebbles to the bottom-most part of your raised beds assist with drainage. Additionally, it prevents water from pooling around the base, leading to plant root rot.
You can also use clay pebbles on top of beds and containers to serve as a mulch. At this mulching stage, the pebbles prevent excess evaporation, trapping moisture in the process. These clay pebbles also cast shade over soil top layers suppressing weeds and sheltering beneficial microbes from the hot sun rays.
Coco Coir
Also known as coco fiber, coco coir is made from coconut husks. Besides lightening compact soil, these light fibers offer excellent water retention. Some growers use pure coco substrate and add a specific amount of particular nutrients in growing weed. But if you want to amend existing soil, it's wise to add about 30% coco coir to your cannabis soil, based on the soil composition of the base soil.
Vermiculite
Just like perlite, vermiculite is a heat-treated mineral most growers use to make their cannabis soils lighter. It also helps in water retaining. Although both vermiculite and perlite come with the same traits, they have opposite uses. Go for perlite to increase drainage and airiness, while vermiculite is perfect for increasing water retention. Fortunately, you can apply both to your cannabis soil as they work well together. Approximately 10% vermiculite is sufficient.
Worm Castings
Worm castings are often viewed as natural soil amendments as they feature countless beneficial microorganisms for healthy growth. Worm castings can also improve the drainage and texture of your soil, not to mention water retention. Use approximately 25-30% worm castings to amend your soil.
Nutrients
If your DIY soil for cannabis is rich in organic materials, chances are you won't add nutrients to it. Don't make the mistake of vegetable scraps and cow manure to your soil to fertilize it. Your soil will end up becoming too hot for your weeds, hurting their development in turn.
So, if you want to reuse your vegetable scraps effectively in your garden, consider decomposing them first. And if you opt for nutrients as an ideal amendment to improve soil quality, purchase bottled solutions specially tailored to your cannabis plant's phase of growth.
Best Soil for Growing Marijuana: Buyers Guide
Buying the best soil for your marijuana plants is one of the significant deciding factors in terms of your plant health and general relief. These factors will help you find the perfect potting soil mix for cannabis.
Number of Cannabis Plants
Before you start thinking about how you'll spend your money, how many cannabis plants will you grow? By answering this question, you'll be able to know how much cannabis soil you need for your project. For instance, if you're growing weed in small containers, there's no need to purchase a bale of cannabis soil to get the job done.
Photoperiod Vs Autoflowering
Another essential factor to consider when searching for the best soil for your weed is the type of cannabis plants you'll b growing. Autoflowers prefer a light soil mix with few added nutrients. The most commonly used substrates when growing autoflowering plants are peat-based soil mixes, coco coir, and additional perlite for drainage.
Note that when dealing with autoflowers, stay away from ready-made stand-alone amended soils and heavily fertilized soils. This is because they can sometimes deliver too many nutrients to your plants, especially seedlings, causing nutrient burn. The same applies to specific amendments, such as guano, as they can overload your plants with nutrients.
For photoperiod plants, it's beneficial to start them out in seedling pots with a soil mix that contains little to no nutrients. You can then replant your seedlings after a few weeks in more suitable soil. In the later growth stages, mature marijuana plants are much better at tolerating higher nutrient levels than seedlings.
Living Soil or Not?
Next, you need to know whether you're on the hunt for a soil mix with beneficial microbes or not. Many growers often question this idea at first. However, fungi and bacteria play a pivotal role in disintegrating nutrients for your plants. Simply put, these microbes facilitate improved nutrient absorption, enhance root growth, and protect your plant against harmful fungi and bacteria.
Grow Your Weed Like a Pro
Generally, all plants need the right type of soil with appropriate nutrients, drainage, and aeration. With this quick buying guide, you can now comfortably find the best soil for growing weed and avoid trial and error techniques. Overall, Fox Farm's Happy Frog organic soil is the best soil mix for cannabis. Whether you're a small-scale grower or a commercial cultivator, Happy Frog is a high-quality, inexpensive, bug-free potting mix for all kinds of cannabis strains.