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Best Soil for Cannabis

Cannabis, like all other plants, thrives from an ample supply of water, oxygen, and nutrients. These three base components are responsible for your crops’ overall health, growth rate, and final yield.

Of these three factors, cannabis soil composition is one of the most easily modified to suit the needs of cannabis crops. Due to this, marijuana soil mixtures are a booming industry. With this being the case you’re probably wondering is there an overall best soil for cannabis?

Although the nutrients in cannabis soils themselves aren’t altered, they are added in specific amounts that promote healthy growth, and most importantly, healthy soil for growing marijuana. Without this pre-made soil for weed, cultivators would be left to compose their own soil for marijuana.

Pre-made cannabis potting soil allows beginners and professionals alike to jump into the fast lane for growing marijuana plants. You’ll find everything your plants need in these marijuana soil mixes, such as beneficial bacteria, fungi, macronutrients, micronutrients, vitamins, and more.

Furthermore, using the best organic soil for cannabis will provide a more natural form of growth, as compared to the hyper-accelerated growth of hydroponics or aeroponics.

We’ve sifted through the best soil brand for weed to find you the very best soil for growing cannabis. Whether you’re searching for the best organic soil for cannabis or the best soil for indoor cannabis – we’ve got your cannabis plants covered so they can grow on cruise control.

FoxFarm Ocean Forest Potting Soil

FoxFarm Happy Frog Potting Soil

Coast of Maine – Platinum Grower’s Mix, Super Soil

FoxFarm Strawberry Fields Potting Soil

Fox Farm Salamander Soil Mix

Organic Super Soil Concentrated Strength

Purple Cow IndiCanja Organic Living Soil

Super Soil Autoflower Concentrate

Canna Terra Professional Soil Mix

Brut Super Soil

Mother Earth Terracraft All Purpose Potting Soil

Roots Organics Original Potting Soil

SoHum Living Soil

Fox Farm Original Soil Mix

BioBizz Soil


KIS Organics

Kryptonite Soil

Big Rootz Soil

Royal Gold Tupur

Gaia Green Living Soil

FoxFarm Ocean Forest Potting Soil

FoxFarm Ocean Forest Potting Soil is a tried-and-true soil mix for much of the cannabis community. It’s one of the easiest soil mixes to use for all stages of plant growth, whether from seedling to harvest.

A massive benefit for FoxFarm Ocean Forest is the fact that it’s already set to the ideal pH range. 6.3 to 6.8 pH is the ideal range for plants growing in soil for nutrient uptake. This makes Fox Farm Ocean Forest soil incredibly efficient, and your cannabis plants will likely show it with vigorous growth.

FoxFarm went above and beyond by offering a two-pack, which enables cultivators with additional potting soil. However, the price comes to around $30 per bag, which is still on the high-end for an organic potting soil.

Although you’ll spend a substantial amount of money for FoxFarm Ocean Forest, it will pay for itself, considering you won’t need a pH pen. If you’re looking for an easy-to-use potting soil mix – this is it.

  • Simple to use soil mix
  • Two-for-one deal saves money in the long run
  • pH adjusted
  • Ideal soil mix for seedlings to mature plants
  • Expensive if only growing a couple plants
  • Not enough perlite for aeration
  • May require supplemental nutrients for the flowering phase

FoxFarm Happy Frog Potting Soil

FoxFarm Happy Frog Potting Soil is one of the best and highly rated organic soil for cannabis plants. It’s perfect for seedlings and young plants because It contains mycorrhizal fungi and other beneficial microbes.

The nutrient source of Happy Frog soil stems from bat guano, earthworm castings, and forest products, such as wood chips. There are enough nutrients to last an entire cycle, from seedling to harvest.

Fox Farm didn’t overdo the nutrient content for a very specific reason, which was not to burn your plants. Many other soil brands create “hot” soil mixes by placing an overly-high nutrient content, but this is not the case with FoxFarm Happy Frog Potting Mix.

This is one of the best potting soil mixes for cannabis, especially for beginners. This is also the best soil for cannabis seedlings because they don’t require a high level of nutrients. If you’ve been looking for a gentle cannabis-specific nutrient mix – this is it.

  • An ideal composition that doesn’t drain too fast
  • Perfect soil for seedlings to mature cannabis plants
  • Comes loaded with worm castings and soil microbes
  • Insect free
  • Doesn’t provide enough P & K for the flowering phase
  • Contains a large number of wood chips
  • Similar to standard garden soil mixes

Coast of Maine – Platinum Grower’s Mix, Super Soil

Coast of Maine soil is a boutique soil mix brand. Their Platinum Grower’s Mix is intended for growers that don’t want to spend additional money on pH monitors and associated products.

Coast of Maine Platinum Grower’s Mix is a stand-alone organic soil mixture that contains mycorrhizae, kelp meal, fishbone meal, lobster compost, alfalfa meal, and worm castings. This organic soil mix is jam-packed with everything your plants need to thrive.

However, all of these high-quality ingredients come in at a hefty price. If you’re willing to stomach the bill, you’ll find a hearty harvest of aromatic and cannabinoid-rich flowers come harvest time if you choose to incorporate Coast of Maine soil.

Although Coast of Maine Platinum Grower’s Mix is expensive, it performs exceptionally well. This is one of the best soil mixes for cannabis we’ve seen, and it’s highly suitable for both beginners and professionals alike.

  • High-quality organic ingredients
  • No need to pH adjust
  • No supplements needed
  • Grows cannabis plants from seedling to harvest
  • Great for plants in large pots & containers
  • One of the most expensive brands on the market

FoxFarm Strawberry Fields Potting Soil

FoxFarm Strawberry Fields Potting Soil is a coir-based mix, which means it will have better drainage and hold less water than peat mixes. Some cannabis growers prefer fast-draining soils to avoid overwatering their plants; however, they may need to water more often with FoxFarm Strawberry Fields compared with growing in a peat-based soil mix.

FoxFarm Strawberry Fields Potting Soil and Ocean Forest by FoxFarm have a lot in common. They’re both made from similar ingredients: worm castings, bat guano, oyster shell, aged forest product, peat moss are the same between both soils. Strawberry fields soil has dolomite lime while ocean forest has granite dust instead. In addition to this, they also contain coco fiber and crab meal shrimp meal kelp meals fish emulsion respectively.

FoxFarm Strawberry fields is a great potting soil that will produce luscious and flavorful buds. You’ll be pleased with the overall cost, appearance, ease of use as well as its beneficial Mycorrhizae bacteria.

  • Fox Farm Quality
  • Priced Competitively
  • Highly rated
  • Buy from reputable seller and check date on product upon arrival

Fox Farm Salamander Soil Mix

Cannabis plants grown in hot climates love to be hydrated during growth phases, and under optimal moisture conditions, beneficial microorganisms will flourish while nutrient uptake will also increase. In the Fox Farm Salamander Soil Mix, we have an ideal soil for rooted cuttings and young cannabis plants that’s also great for both indoor & outdoor cannabis cultivation.

This salamander soil is rich in nutrients, holds water extremely well, and feels almost perfect in texture when it is wet. It’s the best choice for cannabis plants that love moisture as the quality of this soil is top-notch. If you have cannabis plants that require less moisture then this soil can still be used by mixing with a substrate like vermiculite, perlite or pumice stone.

  • Excellent at retaining moisture
  • Another Fox Farm Favorite
  • Quality ingredients
  • Again, as with all soil bought online only buy from reputable sellers and check contents on arrival

Organic Super Soil Concentrated Strength

The Organic Super Soil Concentrated Strength is formulated to create the perfect growing environment for your cannabis plants. They contain a wide variety of beneficial microorganisms and organic nutrients, all of which work synergistically to provide rapid growth and bountiful yields.

Although Organic Super Soil Concentrated Strength is one of the best organic soils for cannabis, it’s still relatively expensive compared to other products with similar ingredients.

A single bag will not fill an entire 5-gallon pot, which makes this an expensive product if you’re growing more than one cannabis plant. Although the instructions recommend cutting this product with a standard potting mix, it won’t last very long.

Furthermore, the Organic Super Soil Concentrated Strength has a strong odor, which is a significant downside if you must be discreet.

Although Organic Super Soil Concentrated Strength is a premier potting mix for cannabis plants, it’s not recommended if you grow more than a handful of plants at once.

  • Organic
  • Contains a wide range of beneficial microorganisms
  • Simple to use
  • Perfect for all stages of growth
  • Very expensive for its small size
  • Will not fill a single 5-gallon pot
  • May contain pests

Purple Cow IndiCanja Organic Living Soil

Purple Cow IndiCanja is the new kid on block in terms of cannabis soil. Purple Cow Organics produce a whole host of different organic products, including seed starter mix, BIOActive vegetable Supercharger, right up to their Purple Cow IndiCanja Organic Soil.

This plant-based, natural organic soil mix contains the necessary minerals and nutrients to start your seedlings on their journey. Having been scientifically formulated and tested Purple Cow IndiCanja is lauded by the people at IndiCanja as good for all stages of plant growth, from young seedlings all the way through to flowering.

IndiCanja bills their soil as developed by growers, for growers as well as being ideal for beginners or pro’s, an all-in-one soil perfect for every stage of growth.

We already know about the qualities of someone like FoxFarm Soil, but the big question is, is there room for another organic soil? And ultimately does the Purple Cow IndiCanja made by Purple Cow Organics have what it takes to sit among the top manufacturers?

Whilst a small number of consumers have experienced fungus gnats, the top-rated reviews from users so far would suggest they do, but the proof is in the pudding, or should we say the harvest…

  • Certified by the Organic Materials Review Institute
  • All-in-one Super Soil
  • Good for Different Stages
  • Expensive
  • Some Bags May Be Infested With Fungus Gnats

Super Soil Autoflower Concentrate

Here we have a fantastic but pricey soil in the Organic Super Soil Autoflower Concentrate mix, which is a specially formulated version of the original “organic super soil”.

What makes Natures Living Soil so good is the microorganisms they include, everything from Glomus Aggregatum, Glomus Etunicatum, Glomus Intraradices, Glomus Mosseae, Pisolithus Tinctorius, Scleroderma Cepa, Scleroderma Citrinum, Trichoderma Harzianum and so much more!

This enables the cannabis cultivator to take their plants all the way from seed, straight through to harvest.

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Natures Living Soil as always deliver a great organic Autoflower mix with some fantastic ingredients:

  • Organic Earthworm Castings
  • Azomite
  • Epsom Salt
  • Coconut Water Powder
  • Aloe Vera The Microorganisms
  • High Quality Bat Guano
  • Blood Meal, Bone Meal
  • Fish Bone Meal, Alfalfa Meal
  • Kelp Meal
  • Dolomite Lime

Yes, the Super Soil Autoflower Concentrate is expensive, and the quantities may not be the best, but when you’re after a premium autoflower soil and can stomach paying that little bit extra, then Natures Living Soil is always a safe bet.

  • All-In-One
  • Top Rated
  • Established Soil Brand
  • Price Could be Better

Canna Terra Professional Soil Mix

CANNA Terra Professional soil is probably better known to cultivators that reside in the UK, as it’s not widely available in the USA or Canada.

This nitrogen-rich potting mix is not only highly rated but also very reasonably priced. With thousands of happy customers across the UK, Canna Terra has been in the soil business for a long time and knows it like the back of their hand. They make everything from potting soil to nutrients for plant cultivation.

What makes CANNA Terra Professional potting mix different from your everyday soil is the organic rich ingredients. Sphagnum moss peat, compost, worm castings, perlite, and a special ‘natural plant booster’ to name a few.

Canna Terra bills their potting mix as the ideal soil mix for indoor and outdoor cultivation.

The high value organic ingredients CANNA Terra uses such as airy peat moss helps to prevent diseases and promote exceptional root development whilst delivering formations of thicker stems and higher yields. Low sickness rates and faster metabolism helps to ensure increased production.

Because of the above characteristics, CANNA Terra Professional Soil Mix is preferred by many UK growers for growing a wide variety of plants.

CANNA Terra Professional Mix makes an excellent bed improver that delivers a complex water/air system ideal for virtually every form of cultivation.

  • Highly Rated
  • Great Price
  • Popular in UK Cultivation
  • Well-known Established Brand
  • Availability
  • Purchase from official store and look out for infestations

Brut Super Soil

If you’re after a premium all-purpose soil packed full of nutrients and beneficial microbial life then this super soil by Brut may be the one for you.

We’ve previously featured their highly rated and popular worm castings in our best worm casting review. Well, Brut has now released this fantastic new all-in-one soil to compete with the more established well-known brands.

Brut super soil features some superb natural ingredients including –

  • Worm Castings
  • Mycorrhizal Fungi
  • Azomite
  • Kelp

Developed by experienced professionals, this super soil has all the good bacteria and microbes you want, and need. The included ingredients have the most robust, beneficial microbial life alongside the perfect mineral balance.

If you’re looking to experiment with a different soil for your next cannabis grow, then why not give Brut super soil a try? You never know, your plants may just find their new best friend.

  • Great price
  • Good company
  • Top rated
  • None

Mother Earth Terracraft All Purpose Potting Soil

Developed by experienced horticulturists, chemists, and biologists, Mother Earth Terracraft All Purpose Potting Soil is another highly rated, and popular soil for cannabis cultivators to consider at a very reasonable price!

Featuring an abundance of healthy ingredients, this all-in-one offering can help to nourish your cannabis plants all the way from seed to harvest!

Mother Earth all-purpose potting soil creates the perfect conditions for your plants, whether you’re growing indoors or outdoors. Aeration is moderate and the NPK is 0.19-0.08-0.11.

This well-blended soil mix includes ingredients such as;

  • Peat moss
  • Perlite
  • Forest products
  • Earthworm castings
  • Yucca
  • Very good price
  • Highly rated
  • Established brand
  • None

Roots Organics Original Potting Soil

Roots Organics Original Potting Soil is an ideal choice for fast-growing, heavy-feeding plants. It has a balanced air to water ratio of porosity and water retention that allows you to frequently feed your prized possessions without worrying about their roots rotting or drying out too quickly. Roots Organics soil bags double as pots – just cut the top off, drop in your plant/seedling (or sapling) with ease!

This Original Potting Soil from Roots Organics contains many ingredients which work together to provide your plant with the nutrients it needs. It has beneficial mycorrhizal fungi, Funneliformis mosseae, and Rhizophagus intraradices that enhance uptake of plant nutrients as well as increase root biomass.

  • Highly rated
  • Good ingredients
  • All-purpose great for beginners
  • Check sizing
  • Buy from a reputable seller and check for fungus knats
  • Bags are plastic

SoHum Living Soil

SoHum Living Soil is designed by growers for growers, helping to make the cannabis cultivation process an easy one. It contains potassium, phosphorus, nitrogen, calcium, sulfur, and magnesium – all essential nutrients required by plants to grow healthy crops with a strong flavor.

Sohum Living Soil Mix comes with a specially blended mix of ingredients that includes kelp, meal, crab meal, bone meal, and alfalfa. The soil also contains perlite which helps with water retention and peat moss. Lastly, worm castings are added as they contain beneficial microbes for healthy plant growth making this mixture perfect for indoor or outdoor cultivation.

Sohum Soil has been purposely created to deliver rapid development of your plant’s root system and eliminates the need to flush, alongside increasing yields and producing trichome-covered buds full of flavor and aroma.

  • OMRI certified
  • Fully amended living soil
  • No synthetic chemicals
  • Highly rated
  • Made by growers for growers
  • Ready to use
  • May not be the best option for all stages

Fox Farm Original Soil Mix

Fox Farm Original Soil Mix is made up of aged forest products, sphagnum peat moss, and earthworm castings. All these ingredients are used to make the soil more effective at holding moisture around plant roots which in turn makes for glorious cannabis buds!

Fox Farm Original Mix is an exceptional mix for raised bed planting. Ready to use straight out of the bag, it can be used to amend existing garden beds as well. This mix contains earthworm castings and beneficial micronutrients that work perfectly together in supporting healthy crops with strong root systems throughout all stages.

Fox Farm has carefully considered each aspect for optimal plant development when making their planting mix so it can provide all the elements needed at any stage throughout your cannabis plant’s life cycle.

  • Good all-round soil
  • Highly rated
  • Holds moisture
  • Pricey

BioBizz Soil

Many growers will have already heard and know about some of the fantastic grow products BioBizz produce but for those that don’t BioBizz is a well established name within the growing community, especially for many UK growers.

Two of their best rated and most popular products are their BioBizz All-Mix Soil and BioBizz Light-Mix soil.

BioBizz soil includes everything your plants require from seed to harvest. Their All-Mix is a fantastic all round potting mix that features ingredients such as worm humus, perlite, sphagnum peat moss, garden peat and BioBizz very own pre-mix recipe.

It’s a great heavily fertilized mixture that provides a full micro-active ecosystem. Nutrient filled to provide a rich soil ideal for long term plant health and full lush growth.

BioBizz Light-Mix Soil is just as, if not more popular amongst growers than their All-Mix soil and is the ideal mix for young seedlings and to develop rapid root growth for organic growers.

Containing only natural organic elements, Light-Mix is very highly rated and recommended for beginners and more experienced growers alike.

Available in the United Kingdom and the United States, alongside being competitively priced, most cultivators should have no problem sourcing BioBizz Soil for their next grow.

With a host of beneficial ingredients BioBizz Light-Mix has been specifically formulated to encourage vigorous growth in, seedlings, cuttings, and young plants. It’s 100% certified for organic use and features the very best sourced Baltic peat.

All in all, BioBizz Soil is another contender in our list of cannabis soil.

  • Available In 20L & 50L Bags
  • Popular Amongst UK Growers
  • Also Available In The United States
  • Well-Known Established Brand
  • Highly Rated By Growers
  • All-Mix & Light-Mix Variations
  • Check Contents On Delivery & Buy From A Reputable Seller


BuildASoil’s 3.0 Recipe is an excellent potting soil that can be used for cannabis plants and that provides the perfect balance of nutrients to give your marijuana plants everything they need, without any dirty ingredients!

This potting soil from BuildASoil is one of their heaviest amended soil recipes to date and a firm favorite in the growing community and is available in sizes of half a cubic foot, one cubic foot, one cubic yard tote, pallet size, and truckload!

BuildASoil Super Soil is a high-quality all-in-one potting soil mix that will provide your plants with everything they need for successful growth from seed to harvest, the only thing that needs adding is water!

This formula has been the cannabis growers favorite because of the quality and testing that has gone into the making of it alongside being ready to go as soon as you open the bag.

  • Good for all stages of growth
  • Respected well-known soil brand
  • Highly rated
  • Pricey

KIS Organics

KIS Organics Biochar Soil Mix is a revolutionary “water only” soil mix registered for organic use with CDFA. Ingredients are composed of natural and organic minerals, so you can be sure that your plants will grow from seed to harvest without nutrient burn.

KIS soil is ready to use right out of the bag and has all the beneficial biology, nutrients, minerals your plant needs. You’ll never have a need for bottled supplements ever again and this biochar soil will make your plants happier and healthier for up to 6 months with all the nutrients they need. All you have to do is add water!!

KIS Organics uses 8% Black Owl’s biochar and inoculates this soil mix with additional microorganisms to further increase microbial life and nutrient cycling, KIS soil is 100% natural without any synthetic chemicals and can be used indoors or outdoors to achieve a healthy cannabis crop.

  • Lab tested
  • Respected cannabis brand
  • Multiple sizes available
  • Pricey

Kryptonite Soil

For our Canadian readers we have a great all-natural fully amended synthetic free water only living soil in the form of Kryptonite Soil created by a husband and wife team over at Next Gen Soil. A Canadian based family run soil brand started in 2011.

Kryptonite Soil has been specifically formulated for cannabis cultivation and features an abundance of beneficial ingredients to help your cannabis plants flourish.

If you’re after a locally sourced Canadian cannabis soil, then look no further than Kryptonite soil, it’s great for seed germination and for all stages of growth, alongside featuring the very best worm castings all produced locally on site, ensuring the highest standards possible.

Kryptonite Soil is available in three sizes, 1.5 C.U FT, 30 C.U FT, and 60 C.U FT bulk bags respectively and is priced competitively compared to other water only and living soil brands.

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Next Gen Kryptonite Soil is extremely versatile and can be utilized all year round both indoors or outdoors, in pots and containers, alongside working well with existing soils and as a top dressing. It also requires no flushing as it’s completely natural, working in natural harmony to continually feed and protect your cannabis plants from pests and diseases.

  • Made In Canada
  • Added Ingredients Sourced & Produced Locally
  • Cannabis Specific Soil
  • Great For All Stages
  • Multiple Sizes Available
  • All-Natural Living Soil
  • Not Widely Available in The USA

Big Rootz Soil

When it comes to the best cannabis soil, there’s not many growers that haven’t heard of Big Rootz soil or it’s creator “The Soil King”.

With a considerable online following, the self proclaimed Soil King claims Big Rootz potting soil is built by growers for growers. It’s hard to dispute this claim having looked deeper into the considerable ingredients list Big Rootz soil mix features compared to other competitors in the market.

Their ingredient list, lists pre-washed coco-coir, peat, and compost as their base materials alongside worm castings, pumice, seabird guano, langbeinite, amongst many others.

If you plan to utilize Big Rootz in your soil recipe, then just like Royal Gold soil, it’s likely that you’ll need to supplement your cannabis plants during the flowering phase.

Another plus for Big Rootz soil is that it’s tested pesticide free and non-GMO alongside being certified green by the CGC.

All in all, Big Rootz soil is an easy to use soil amendment that’s ideal for indoors, outdoors, in greenhouses and as a soil builder to your existing soil mix. Available from big online retailers as well as The Soil King website, most growers should have no problem sourcing Big Rootz Soil for their next grow.

  • Formulated With Mycorrhizae For Enhanced Root Growth
  • Contains Water-Retaining Peat
  • Contains Pre-Washed Coco-Coir To Reduce Nutrient Lockout
  • Easy-To-Use Out Of The Bag
  • Expensive Depending On The Retailer You Buy From

Royal Gold Tupur

Our next pick may be a surprise for many growers, as it’s not an out and out soil but more of a soilless mix that was originally designed for drip to waste systems.

Having said that, one of the reasons we’ve included it our list of cannabis soils is its versatility factor and the fact if you want to achieve the best soil for cannabis you’ll need to amend your existing cannabis soil recipe at some point, and when that need arises, Royal Gold Tupur should be at the top of your list.

Growers have experienced some amazing results using Royal Gold Tupur in conventional gardens as well as hydroponic systems.

If you were to search for Royal Gold soil you’d find a host of results but the truth is, many if not all the products Royal Gold produce are either coco fiber based mixtures, fertilizers, and such. As mentioned above, they don’t currently produce an out and out soil.

What they do produce though are extremely high quality grow media products that use 100% organic materials and can be added to your existing setup and/or your current soil to make a soil recipe your cannabis plants will thrive within.

All Royal Gold products go through rigorous testing and are produced in Humboldt. Royal Gold Tupur is no exception to this, before being released it must meet Royal Golds and Humboldt’s high standards.

Great as an amendment to existing soil or as a standalone grow media, Royal Gold Tupur is a high porosity mix that features coco fiber, basalt, perlite, and aged forest products, that when used correctly delivers all the necessary NPK your cannabis plants need.

As stated though, this is a essentially a soilless medium that will need to be amended in most cases especially with calcium and magnesium to see best results.

Such is the versatility of Royal Gold Tupur it can be used in drip to waste systems, ebb and flow systems, deep water culture systems and even aquaponic systems, this is all alongside your traditional potting soil mixes. A truly great little medium that provides the required oxygen to your root systems thanks to the included perlite.

  • Versatile
  • Highly Rated
  • Organic
  • Produced In Humboldt
  • Available From Multiple Retailers
  • Will Need Amending To See Best Results

Gaia Green Living Soil

Gaia Green Living Soil is a premium potting mix that provides plants with the optimal root environment. Gaia Green soil is enriched with glacial rock dust, dolomite, feather meal, alfalfa meal, bone meal, rock phosphate, blood meal, fishbone meal, mineralized phosphate, insect frass, and mined potassium sulphate to ensure that your plants get the nutrients they need.

The high porosity and moisture retention of Gaia Green Living Soil creates an ideal rooting environment for potted plants.

Made in Canada, and available in 30L bags and with an NPK of 01 – 0 – 0, this top-rated Gaia Green soil is packed with peat moss, perlite, coconut coir, fir bark, composted porcine litter, African nightcrawlers, and worm castings – all of which work together to support and promote healthy beneficial microbial activity.

Additionally, Gaia Green Living Soil is pre-charged with Gaia Greens very own proprietary slow-release organic fertilizers to provide your plants with everything they need to grow big and strong throughout every stage of growth.

  • Peat Moss
  • Perlite
  • Coconut Coir
  • Fir Bark
  • Composted Porcine Litter
  • African Nightcrawler
  • Worm Castings
  • Expensive Shipping Costs If Outside Of Canada

Best Soil For Cannabis: Buyers Guide

Buying the best cannabis soil for your cannabis plants might not seem important, but it’s one of the biggest deciding factors when it comes to plant health and overall yield.

Cannabis plants take anywhere from 4-6 months from seed to harvest. Clones may take upwards of 3 months to complete their life cycle. Not only is this a significant investment in time, but also the energy needed to fuel their growth.

This is why we’ve compiled this buyer’s guide to help you find the best potting soil to grow cannabis.

Qualities to Look for in a Good Cannabis Soil?

Many ready mixed store-bought cannabis soils are already amended within the correct ratios so should be ready to go in many cases. Of course, you can always amend the soil further if needed and as previously mentioned, many companies also produce cannabis soils for specific stages of growth, so research as much as possible and buy a potting soil that is correct for your individual situation.

  • Loamy Soil

Loamy soil is a mix of organic compounds and various ratios of clay, silt, and sand. Loam soil mixes are a popular choice among cannabis growers and should be near the top of your list when searching for the best soil for cannabis as they offer excellent drainage alongside ideal water retention. A quality organic loam soil will be rich in nutrients and provide plenty of oxygen.

  • Silty Soil

More of a coarse soil, silty soil mixes are abundant with beneficial organic minerals. Compared to loamy soil, a silty soil mix can be regarded as having fair-good water retention, with drainage that is about average. Silty soils mixes are very often extremely fertile alongside being very malleable, and easy to amend.

  • Sandy Soil

Another coarse soil mix is sandy soil, not the best kind of soil for many cannabis growers as water retention is poor-fair but sandy soil does have the benefit of good drainage! Although a common downfall to sandy soils is the washing away of vital nutrients. Again, just like silty soil, sandy soils are fairly easy to work with and amend.

  • Clay Soil

A heavy soil compared to other soil mixes, clay soils are another soil option for growers wanting a soil mix rich in nutrients and essential minerals, they’re made up of fine minerals. A very good option for organic cannabis grows. Clay soils have very good water retention but perform poorly drainage wise.

Is Growing in Soil Easy?

This is the main question that beginners ask. In fact, growing cannabis in the best potting soil for cannabis is one of the easiest methods because it’s by far the most natural.

The vast majority of cannabis soil brands offer “plug-and-play” soil for indoor marijuana. This means that you don’t need to do anything – except water them.

In these cases, you’ll need to look for the best soil for marijuana plants that are already within the optimal pH range. By finding a pH-balanced cannabis soil mix, you won’t need to worry about complicating matters with a pH pen.

The Number of Plants

Before you give your hard-earned money away, how many cannabis plants will you grow? This is one of the first questions you must ask yourself because it’ll paint a clear picture of how much soil for weed you’ll need.

If you’re growing a single plant or 6-plants in small containers, you won’t require a bale of soil for marijuana plants to fit your needs. Instead, you can get away with purchasing a single bag of soil for growing marijuana to keep your costs to a minimum.

However, if you’re growing multiple plants in large containers, then you’ll need to purchase multiple bags of the best marijuana soil or a large bale-size bag of cannabis potting soil.

Whether you’re growing a warehouse full of cannabis plants or a single plant in your closet, knowing how much cannabis soil you need is the very first step you must take.

Stand-Alone or Supplement-Based?

This is the next important factor that you must consider. Do you want the best soil for growing weed that’s filled with all the necessary nutrition for your plants, or are you seeking a mild soil for marijuana that can be amended with additional supplements?

If you choose the best potting soil for marijuana, then it might not be suitable for seedlings due to the overall strength. If you decide to go with a milder soil for marijuana, then you’ll need to purchase additional nutrients.

Some growers find more freedom in purchasing marijuana soil mixes that contain fewer nutrients so they can fine-tune their overall nutrient content.

However, this method is only recommended for cultivators with experience. If you’re a beginner, fine-tuning soil for weed may prove to do more harm than good.

Beginners will benefit from utilizing stand-alone soil for cannabis because it contains everything your crop needs to thrive from seed to harvest.

Although these products are not packed to the brim with nutrients, they will allow you to grow vigorous and high-yielding crops without the worry of nutrient burn.

Organic or Inorganic?

This is another essential question you need to ask yourself. Organic marijuana soil contains ingredients that are from organic sources (worm castings), which are scientifically proven to be better for the environment and your overall well-being.

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Inorganic cannabis potting soil tends to be cheaper in cost, but the price difference isn’t as large as in the past. Ultimately, this is a very personal question that only you can answer.

Living Soil Or Not?

Next, you’ll need to understand if you’re looking for the best soil for growing marijuana that contains beneficial microbes or not.

You may question this idea at first, but fungi (mycorrhizae) and bacteria play an integral role in breaking down nutrients for your prized cannabis plants.

In other words, beneficial microbes facilitate enhanced nutrient absorption, promote root growth, and provides a protective barrier against harmful bacteria and fungi.

Although you’ll likely see an increased price tag on the best soil for weed that contains beneficial microbes, it’s well worth it when you consider the effort it takes to grow high-quality cannabis flowers.

Photoperiod or Autoflowering Plants?

Another important factor to consider when looking for the best soil for marijuana is the type of plants you will be growing, by this, we mean will your grow room be filled with autoflowering plants or photoperiod?

This is definitely something that should be taken into consideration as if you’re growing autoflower plants, then they will likely prefer a cannabis soil mix that is light with few nutrients.

One of the more commonly used substrates growers use when growing autoflowering plants are carefully balanced peat based cannabis soil mixes with coco coir and additional perlite to achieve the required aeration and drainage.

An important reminder regarding soil mixes for weed, especially if you’re considering growing autoflower plants, is heavily fertilized cannabis soils or ready-made stand-alone amended marijuana soils can/will sometimes deliver too many nutrients for young seedlings resulting in nutrient burn (so bear this in mind!).

Additionally, when growing photoperiod plants, it may be more beneficial to start them in a seedling pot with a cannabis soil mix specifically designed as a seed starter with fewer nutrients. You can then replant your precious seedlings when the time is right in a more suitable cannabis soil for the next growth stage. It’s important to remember that mature cannabis plants in the later stages are much better at tolerating much higher nutrient levels than seedlings.

Do You Need Additional Aeration?

Just like animals, your cannabis plants rely on oxygen to thrive. Alongside water and nutrients, air is a necessity when growing cannabis plants in soil.

Perlite is a primary material that cannabis growers use to increase the amount of air inside a cannabis potting soil mixes. Not all cannabis soil brands contain perlite, so it’s essential to understand if your soil for marijuana is too heavy.

Air pockets within your cannabis potting soil mix not only provide oxygen for the roots, but they also allow the root system to expand rapidly.

Furthermore, consistent air pockets within the potting soil mix enhance drainage, which will reduce the possibility of fungus and bacterial rot.

How To Grow Cannabis in Soil

Growing cannabis in the best cannabis soil is incredibly straightforward, especially when it’s already pH adjusted. Here are a few tips on getting your potting soil ready for your marijuana plants.

The first thing you need to do is fill your container 3/4 full with potting soil. Gently place your plant, and carefully add additional potting soil to cover the roots.

The cardinal rule is never to compact your cannabis soil. Cannabis roots not only thrive from the nutrients within the cannabis soil mix, but also from the air pockets.

These tiny pores keep roots from rotting, so it’s essential that you refrain from pressing down on your cannabis potting soil mix.

If your marijuana soil mix is already pH adjusted, then you simply add water. Always allow your plant to satisfy its thirst before adding more water to avoid overwatering symptoms.

Grow Medium Guide For Indoor Growers

Are you a novice cannabis cultivator looking for a guide to grow mediums for indoor marijuana growing? Well, you’re in luck. High Times Cultivation Editor Nico Escondido answers all of your grow questions in his weekly Nico’s Nuggets column, and this week, he’s focusing on grow mediums for indoor growers.

The Question: What Grow Medium Is Best For New Indoor Growers?

Long-time reader, first-time grower here! As my wife and I begin our journey in growing, I wanted to get your take on the abundance of indoor grow mediums currently available on the market. As first time growers, we are leaning towards using soil and hand-watering the plants, as I have seen you recommend this approach for beginners several times over the years. However, we are open to doing a hydro system if the medium and system are easy enough to handle. Any advice is much appreciated!

— Carlos & Melinda, via the mailbag at [email protected]

The Answer: The Most Popular Grow Mediums For Indoor Growing

Thanks for writing in Carlos & Melinda—and congratulations on starting your first grow! That is music to our ears here at High Times!

To start, whenever discussing indoor grow mediums, I think it is important to differentiate between “soil” and “soilless” mediums. When we, as growers, talk about using soil indoors, we are actually talking about what is commonly known as “soilless” mediums.

Correct medium choices help genetics reach their potential as seen with this pink Jah Goo.

Actual mineral soil or topsoil is rarely, if ever, used indoors anymore (excluding greenhouse grows). This is simply because there are now better options that can do the same thing as mineral soil. These “soilless” mixtures are peat- or sphagnum-based. When one considers that real earth soil is generally not sold as a sterilized medium and may contain pests, molds or possible diseases/viruses embedded in it, the risk of bringing that into an indoor garden is not worth it—especially when these moss-based mediums look, feel and act very similar to actual soil.

That being said, let’s take a quick look at a few of the most popular mediums for indoor gardens:

There are three types of peat used in agriculture: peat moss, reed sedge and peat humus. Peat moss is the most widely used and is derived from sphagnum and other mosses, varying in color from tan to dark brown. Peat has a high moisture-retaining capacity, being able to hold 15 times its dry weight in H2O, and contains small amounts of nitrogen. However, it has high acidity with a pH range of 3.2 to 4.5. Peat is almost always used in soilless mixtures, rather than as a stand-alone medium, with sphagnum, perlite, wood chips and coco being its primary partners.


Very similar to peat moss, sphagnum is a moss composed of dehydrated acid-bog plants. Being perhaps the most desired moss for agricultural use, it is expensive to produce and as such, it is often used in soilless mixtures alongside peat moss. Sphagnum has very high water-absorbing properties and can absorb 10 to 20 times its dry weight in moisture. Sphagnum moss has a pH between 3.5 and 4.0. Much like peat, sphagnum offers excellent buffering qualities for the root structure, helping to prevent nutrient burn and making it very forgiving for beginner growers.

A soilless, peat-based mixture with perlite mixed in.


Chemically speaking, vermiculite is hydrated magnesium-aluminum-iron silicate. It expands quite a bit when heated, and once expanded, it is extremely lightweight. It is insoluble in water, inert and can absorb huge amounts of water, which is why it is often a key ingredient in soilless mixes. Furthermore, its high cation exchange capacity makes it very good for buffering and use with heavy nutrient programs.


A gray-white mineral mined from volcanic lava flows, perlite is also heated and expanded into small, sponge-like kernels that are extremely lightweight with decent water-retention properties of three to four times its dry weight. Its best feature is that it is very neutral with a pH of 6.0 to 8.0. Unlike vermiculite, perlite has no cation exchange capacity and therefore is poor in buffering. This is why perlite is often used as a spread on top of soilless mediums to help keep moisture locked in below.

Hardened Expanded Clay (HEC)

Similar to vermiculite and perlite, clay can be heated and expanded. However, with clay, the medium becomes much harder after heating. Still, the clay aggregate is porous enough to give it some decent water-holding ability, though not enough for systems using a single daily watering. Rather, this medium is better suited for continuous-flow or multiple-watering hydroponic systems. Inert and sterile with neutral pH, HEC offers little to no buffering properties, but it is highly stable and capable of holding seedling or clone plugs in active hydro systems. HEC can also be used as a bottom layer for drainage in plant containers or as a mixed-in additive for soilless mixtures.

Hardened expanded clay (HEC) being used in a flood-and-drain hydro table.

Mineral Wool

Most commonly known as Rockwool (a brand name), mineral wool is an extremely popular medium for rooting and growing plants, especially in heavy hydroponic systems. Spun from fibers created by melting various rock types, the “wool” is then pressed into various plugs, squares and slabs for growing plants. Mineral wool will hold a considerable amount of water while also allowing for good air permeation. Mineral wool is sterile and inert with a neutral pH, however, it has poor buffering and is generally regarded as a medium for advanced growers.

Coconut Fiber/Coir

Often referred to simply as “coco,” coconut fiber can come in a variety of forms including shredded fibers, small cubes or a finer, more granular medium. Coco is often mixed into soilless mixtures with peat and vermiculite, but it can also be used as a stand-alone medium for potted plants. Derived from coconut husks, coco is sterile and has good water-retention and buffering properties.

Obviously, choosing one of the above mediums hinges a lot on the type of grow system being used in the garden. In terms of the question posed, I would concur that for a first-time grower, using a soilless mix (such as Sunshine #4 or Pro-Mix) and utilizing a daily hand-watering regiment is the best option.

For those with previous experience looking to use a hydroponic system, soilless mixtures are still good for top-feed or drip-irrigation systems. Once you move into the more advanced hydro setups, such as flood-and-drain tables, deep-water culture (DWC) or nutrient film technique (NFT), mineral wool and HEC become better choices.

Remember, whichever way you go, be sure your root zone is easily permeated by air so that roots can get the oxygen they love so much. And when it comes to buffering and choosing your nutrient program remember—less is more, as you can always up your dosages, but correcting a nutrient overload is much more difficult.