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What Is The Best Growing Medium For Cannabis?

What is the best medium to use for your cannabis grow operation? Find out the pros and cons of growing cannabis in soil, coco, rockwool, and hydroponics.

Cannabis cultivators can choose from various growing media and techniques to achieve a successful harvest. Do you want to grow in soil, coco, or go with an elaborate hydroponic setup? What are the pros and cons of each, and which one should you choose? Since choosing the right growing medium is an important step on the path to growing great cannabis, we thought we’d provide a guide to make the process easier.

HOW TO CHOOSE THE RIGHT GROWING MEDIUM FOR CANNABIS

A growing medium is where your cannabis plants develop their root system. Many growers keep it simple with pots of soil, but you can also use coco coir, perlite, rockwool, or go for a fully fledged hydroponic setup.

What’s important to know is that there really is no “best” way to grow. Each medium has its pros and cons, though you may prefer one over the other based on your preferences and resources. As long as the roots of your plants can access water, nutrients, and oxygen, they will grow.

Now, let’s take a look at the differences between each growing medium.

SOIL/COMPOST

Difficulty: Easy
Cost: Low

Growing in soil is the simplest way to get some nice weed plants going, but don’t think that means soil produces poorer results than other methods. Far from it! Many growers say that soil enriched with high-quality compost grows them the best-tasting weed, even if yields aren’t quite as good as in coco or hydro.

The main advantage of soil is that it is forgiving and beginner-friendly, and you can still crop cannabis of top-notch quality. Soil is also widely available and relatively inexpensive.

ADVANTAGES DISADVANTAGES
Seeds, a pot, some soil, and some love are all you need. Good for beginners! Comparatively higher risk of pest infestations, mould, and fungus.
pH fluctuations are typically less severe or problematic. Plants produce lower yields compared to other growing methods.
Many commercial soils contain enough nutrients for 3–4 weeks of growth. Plants grow slower, so it can take longer to spot growing problems.
Soil is the method of choice when you want to grow naturally and organically. Not all soils are optimal for cannabis.
Growing in soil can give you the best-tasting cannabis.
ADVANTAGES DISADVANTAGES
Seeds, a pot, some soil, and some love are all you need. Good for beginners! Comparatively higher risk of pest infestations, mould, and fungus.
pH fluctuations are typically less severe or problematic. Plants produce lower yields compared to other growing methods.
Many commercial soils contain enough nutrients for 3–4 weeks of growth. Plants grow slower, so it can take longer to spot growing problems.
Soil is the method of choice when you want to grow naturally and organically. Not all soils are optimal for cannabis.
Growing in soil can give you the best-tasting cannabis.

COCO/PERLITE

Difficulty: Medium
Cost: Low to medium

Growing in a mix of coco and perlite provides the advantages of a hydroponic grow and the ease of a soil grow.

As a coco/perlite mix does not contain any nutrients, you are responsible for giving hydroponic nutrients from the start. The big advantage here is that you have full control, and your plants will grow as fast as in hydro. Downside: Just as with hydroponics, you will have to closely watch your pH levels. It’s also less forgiving of mistakes than soil.

ADVANTAGES DISADVANTAGES
You can grow big plants with very good yields! You need to administer nutrients from the start.
You have full control over nutrient and pH levels. You need to watch pH and EC levels carefully: A small mistake can quickly lead to problems.
No special equipment needed. Not as widely available as soil. You may need to order coco online.
Coco is a renewable resource.
Coco/perlite is (almost) as easy as growing in soil.
ADVANTAGES DISADVANTAGES
You can grow big plants with very good yields! You need to administer nutrients from the start.
You have full control over nutrient and pH levels. You need to watch pH and EC levels carefully: A small mistake can quickly lead to problems.
No special equipment needed. Not as widely available as soil. You may need to order coco online.
Coco is a renewable resource.
Coco/perlite is (almost) as easy as growing in soil.

ROCKWOOL

Difficulty: Medium/high
Cost: Medium

Previously used only in construction, where it experiences widespread use as insulation material, rockwool has become a top medium for horticulture. Just like perlite and coco, it is a so-called “inert” growing medium that doesn’t have any nutrients in it. Rockwool is made from cotton candy-like fibre spun from basalt rock and has excellent moisture-retention abilities. You can find rockwool for growing in a variety of shapes and sizes, from smaller blocks and cubes to large slabs.

Rockwool is most often used in hydroponics. The roots of the plants receive support from the rockwool as drippers provide water and nutrients.

ADVANTAGES DISADVANTAGES
Rockwool supports a sterile grow with little risk of pests, disease, and infestation. You need to give nutrients from the start.
Like hydroponics or coco, you have full control over pH and nutrient levels. You need to watch pH and nutrient levels.
You can germinate cannabis seeds in rockwool cubes. When transplanting, you can just keep the seedling safely in its cube. You can’t grow organically.
You need to soak rockwool in low-pH water before use.
Rockwool is not natural and doesn’t biodegrade. Reusing rockwool is not recommended.
ADVANTAGES DISADVANTAGES
Rockwool supports a sterile grow with little risk of pests, disease, and infestation. You need to give nutrients from the start.
Like hydroponics or coco, you have full control over pH and nutrient levels. You need to watch pH and nutrient levels.
You can germinate cannabis seeds in rockwool cubes. When transplanting, you can just keep the seedling safely in its cube. You can’t grow organically.
You need to soak rockwool in low-pH water before use.
Rockwool is not natural and doesn’t biodegrade. Reusing rockwool is not recommended.

HYDROPONICS

Difficulty: Medium/high
Cost: High

There are various types of hydroponic setups used for growing cannabis. Some systems hold plants in pots filled with a hydroponic growing medium such as clay pebbles, perlite, or rockwool, with drippers dispensing water and nutrients to your cannabis.

You can also find setups that do not use a solid growing medium at all. In these systems, plants are suspended above a tank, with the roots reaching down into the water/nutrient solution. Some systems may use a combination of these, with the plants in a solid medium and the roots suspended in a tank. Simple dripper setups are relatively affordable, while more elaborate systems that make use of pumps and other equipment can be quite expensive.

ADVANTAGES DISADVANTAGES
Your plants will grow large and fast for maximum yields. You need to maintain the correct pH and nutrient levels.
You have control over the pH and nutrient levels of your cannabis. You need to empty your tank and clean your system once in a while.
You don’t need to feed as much (if you have a recirculating system). You need to give hydroponic nutrients from the start.
Low risk of pests and soil-based diseases. A hydroponic setup will cost more than some pots and a bag of soil.
Your weed may not taste as “natural”.
ADVANTAGES DISADVANTAGES
Your plants will grow large and fast for maximum yields. You need to maintain the correct pH and nutrient levels.
You have control over the pH and nutrient levels of your cannabis. You need to empty your tank and clean your system once in a while.
You don’t need to feed as much (if you have a recirculating system). You need to give hydroponic nutrients from the start.
Low risk of pests and soil-based diseases. A hydroponic setup will cost more than some pots and a bag of soil.
Your weed may not taste as “natural”.

WHAT IS THE BEST GROWING MEDIUM?

In conclusion, there is really no “best” growing medium for your cannabis—each has its own strengths and weaknesses. Many times, it will come down to cost, in which case soil is still the reigning champion.

  • Consider growing in soil/compost if you’re just starting out or simply want to go the most natural route.
  • Consider growing in coco/perlite if you’re already confident growing in soil and feel that you want to upgrade. Growing in coco has the advantage of providing almost all the benefits of hydro, but it’s still essentially as easy as growing in soil.
  • Consider using a hydroponic system if you want the fastest growth, biggest yields, and full control over most aspects of your grow. With many hydroponic setups, you are free to use an inert growing medium of your choice (clay pebbles, perlite, rockwool, etc.), so there is plenty of room for some horticultural experimentation.

HOW TO GROW CANNABIS USING SOIL, COCO, HYDRO, OR ROCKWOOL: FURTHER READING

Are you still on the fence about which growing medium to choose? Here are some articles we recommend reading:

• The Home Grower’s Guide To The Best Soil For Cannabis Choosing The Best Soil For Cannabis: A Home Grower’s Guide.

• Growing Cannabis With Coco Coir Growing marijuana in coco coir is a fantastic alternative cultivation style.

• Hydroponic Cannabis Growing Guide Hydroponics is a method of cultivating plants, specifically cannabis in this case, in a solution of water and nutrients.

• Rockwool For Hydroponic Marijuana Growing Rockwool is a great medium for growing marijuana.

What's the best growing medium for cannabis? Find out the differences between growing cannabis in soil, coco, rockwool, and hydroponics here.

What’s the Best Growing Medium: Soil, Coco or Hydro?

Table of Contents

  • Soil or Compost
  • Soilless Mix (Especially Coco & Perlite)
  • Hydroponics

Introduction to Cannabis Grow Mediums

When talking about growing marijuana, what is a “grow medium”?

A growing medium or grow medium is what you’re growing your cannabis roots in, whether that substance is soil, perlite, coco coir, Rockwool, vermiculite, water, etc. Your marijuana plant will thrive as long as the roots have room to grow and have consistent access to fresh water, oxygen, and the proper nutrients in proper levels. There are a variety of ways to satisfy all these needs of a cannabis plant while growing, and each has its own pros and cons!

Every Grow Medium Must Help Roots Get What They Need: Water, Oxygen and the right Nutrients

Best Growing Mediums for Marijuana

The three main types of grow mediums for marijuana plants are soil mixes, soilless mixes and hydroponics (water). Let’s do a quick breakdown of each one, along with the pros and cons for marijuana growers!

  • Soil or Compost
  • Soilless Mix (Especially Coco & Perlite)
  • Hydroponics

Soil or Compost

Soil or compost is one of the most popular growing mediums for marijuana plants because it is natural, easy to use, and available everywhere.

Good cannabis soil naturally contains at least some amount of nutrients, which means it will provide the nutrients your plants need for at least the first few weeks of life.

Example of Great Cannabis Soil

If you decide to grow cannabis with soil, try using sterilized, loose, non-peat based potting compost. Often these are listed as an “organic potting mix.” I recommend soil mixes with at least 20-30% of a soil conditioner like perlite (little white rocks in the soil). This will provide drainage and keep higher amounts of air/oxygen in the soil, which causes cannabis plants to grow faster.

Plants in soil grow a little slower than in coco or hydro, but soil-grown buds tend to have a stronger smell/taste. Although using a standard soil potting mix and giving nutrients in the water gets results similar to coco, using amended and composted living soil tends to produce buds with a powerful and complex scent/taste profile.

Example of Amended and Composted Living Soil – Just add water!

With living soil, a colony of microorganisms in the soil creates an ecosystem that mimics the best-of-the-best soil in nature. The nutrients are slowly broken down from organic sources and delivered directly to your plant roots. For some reason, plants grown in this type of root environment tend to produce very strong-smelling buds. One thing that’s really great about living soil is you usually don’t need to use any added nutrients.

The result is strong-scented buds grown only with natural processes and all you have to do is just add water and let the soil do the magic! The biggest downside to living soil is that plants tend to grow a little slower than with other grow mediums, and some people don’t like the smell of the composted soil, especially in the house.

Common Cannabis-Friendly Soil Mixes in the US:

  • Composted and Amended “Hot” Soil (great)
  • Fox Farms Ocean Forest Soil (great)
  • Black Gold All Organic Potting Soil (good)
  • Espoma Organic Potting Mix (okay)

Example of Great Soil – Fox Farm Ocean Forest is rich and light, plus it’s packed with nutrients in the right ratio for growing cannabis!

Soilless Mediums (Coco Coir & Perlite)

Soilless potting mixtures that are composed of inert (non-soil) ingredients like coco coir, perlite, peat moss, Rockwool, and vermiculite can be a great choice for growing marijuana.

When growing in a soilless medium, you can treat your plants almost the same as if growing in soil. The main difference is you feed all their nutrients in the water. As a result of your plants getting nutrients delivered directly to their roots, you will often get quicker growth and higher yields than growing in soil (where the roots have to seek out nutrition).

Another advantage of growing in a soilless mix over soil is that you are less likely to run into problems with overwatering or bugs.

Although there are many different possible soilless ingredients, the most popular potting mixes for cannabis contain significant amounts of coco coir and perlite. This combination seems to work especially well for growing cannabis. As a result of coco’s growing popularity, other types of soilless mixes (especially the peat-based ones) have become far less common in cannabis grow rooms over the years.

Even when it comes to soil mixes, you still often see both coco and perlite in the ingredient list, because they help improve the overall properties of the soil.

In fact, I strongly recommend beginner growers start out their plants in a coco-based soilless potting mixture, and I have written a detailed tutorial on how to grow 4-7 oz. of marijuana using coco coir for first-time growers. I’ve also grown a pound of weed in a 2×4 tent using coco coir and a 315W LEC light!

I have personally found coco/perlite to be the most straightforward and forgiving growing medium for indoor cannabis, and over the years I’ve also seen that coco growers seem to be the least likely to run into problems during their first grow!

Coco coir is how I started growing, and I recommend it to anyone 🙂 Here’s me during my first grow with my coco-grown plants:

Learn how to grow cannabis with coco coir or view the Step-By-Step 250W Coco Tutorial to produce 4-7oz on your first grow with coco using auto-flowering strains. I highly recommend this tutorial for beginner growers looking to get started with their first grow!

Common Cannabis-Friendly Coco Coir Mixes in the US:

  • Mother Earth Coco + Perlite Mix (recommended)
  • Fox Farms Coco Loco (great)
  • Roots Organics Soilless Hydroponic Coco Media (great)
  • Make it yourself with our “Coco Coir Rehydration Tutorial (low cost!)

Hydroponics

When people are talking about hydroponics, they’re usually referring to growing your cannabis with the roots sitting directly in water. The most popular style of hydroponics for cannabis plants is known as Deep Water Culture (a.k.a. DWC), and it has a very popular variant known as “bubbleponics” or a top-fed Deep Water Culture (DWC) system.

DWC is one of the few types of hydroponics that can support larger plants. Other types of hydroponics (for example NFT or Aeroponics) have a difficult time growing plants as big and nutrient-hungry as cannabis.

Example of cannabis roots growing directly in a solution of nutrient water

Two hydroponic cannabis plants in the vegetative stage

Example of flowering DWC cannabis plants. They grow so quickly that they can quickly take over your grow room!

Hydroponics can be really scary, but I’ve seen so many first-time growers get great results with hydroponics. The most important thing to remember is to follow the instructions and always get a root supplement like Hydroguard. I love hydro. After growing for several years, I think it may be my favorite grow style. You get the fastest growth and most control over nutrients of any grow medium!

What exactly is hydroponics and is it good for growing marijuana?

By the end of a hydro grow, you may find yourself with huge masses of roots!

Conclusion: What’s the Best Grow Medium for Growing Cannabis?

  • Soil or Compost – Grow in organic composted living soil for the most complex-smelling buds and a “just add water” growing experience. Or start with a cannabis-friendly soil mix such as the popular Fox Farms Ocean Forest soil mix (FFOF already contains enough nutrients to last the first month of your young plant’s life) and give nutrients in the water as plants get older.
  • Soilless Mix – Although this technically includes any grow mix that doesn’t include soil, with ingredients such as coco coir, perlite, vermiculite, etc., most cannabis growers use a mix that’s primarily made out of coco coir and perlite. All soilless mixes are technically considered hydroponic growing since there’s no soil, but most growers think of them as somewhere in between soil and hydro, and you get a lot of the best parts of both. I highly recommend a coco/perlite mix for your first cannabis grow!
  • Directly in Water / Hydroponics – Get some of the fastest growth possible, especially when combined with HID grow lights such as HPS or LECs. I’ve had many of successful grows using a top-fed DWC system, and I think it may be my favorite style of growing.

About Less Common Types of Hydro: Some people grow with plant roots suspended in misted air (aeroponics), in an assembly line (NFT), or in a tank with fish (aquaponics), but these are better suited to smaller plants, and not commonly used to grow cannabis.

So what’s REALLY the best medium? Alright, I’ll stop dancing around what you’re really here for. I’ll rank the popular mediums for different aspects, then I’ll tell you which one I think is the best overall…

Note: The contenders are Soil, Living Soil (composted), Coco Coir (soilless), Hydro (DWC – roots suspended in water)

  1. Hydro
  2. Coco Coir
  3. Soil
  4. Living Soil

Best Smell/Taste Profile:

  1. Living Soil
  2. Everything Else
  1. Living Soil
  2. Coco Coir
  3. Soil
  4. Hydro
  1. Hydro
  2. Coco Coir
  3. Soil
  4. Living Soil

Least Chance of Bugs/Pests:

  1. Hydro
  2. Coco Coir
  3. Soil
  4. Living Soil

BEST CANNABIS MEDIUM OVERALL:

Believe it or not, the best overall medium – in my opinion – is coco coir!

Allow me to explain…

Check out the rankings above; in this case, the medium with the lowest number ranks the best. If you add it all up, Coco Coir ends up being the winner and it’s clear why. Coco coir isn’t the best at anything, but it’s the second-best at pretty much everything: it grows almost as fast as hydro, it’s easier to use than soil, yields second best to hydro and gets fewer bugs than living soil. Coco coir is kind of a jack-of-all-trades and a master of none.

Another cool thing about coco coir is that it’s renewable, so it’s easier on the environment. Most soils use peat which is a finite resource, and hydro can add nutrient water to the water supply. Properly used coco coir doesn’t have any of these problems so you can feel good about using it. Unfortunately, perlite – which is almost always used with coco coir – isn’t renewable, so in a sense, coco coir isn’t renewable because of its dependence on perlite.

Each growing medium that you can use has different care and watering requirements.

Best of the Best: Grow Medium Roundup

We declared coco coir the winner of this little contest, but all the mediums are the best at one thing. Get the best brand of cannabis grow medium to match your preference and grow style.

Common Cannabis-Friendly Coco Coir Mixes in the US:

  • Mother Earth Coco + Perlite Mix (recommended)
  • Fox Farms Coco Loco (great)
  • Roots Organics Soilless Hydroponic Coco Media (great)
  • Make it yourself with our “Coco Coir Rehydration Tutorial (low cost!)

Common Cannabis-Friendly “Living” Soil Mixes in the US:

  • Composted and Amended Living “Super” Soil by Kind Soil (recommended)
  • Super Soil Grower’s Mix by Coast of Maine (good)

Common Cannabis-Friendly Soil Mixes in the US:

  • Fox Farms Ocean Forest Soil (great)
  • Black Gold All Organic Potting Soil (good)
  • Espoma Organic Potting Mix (okay)

Give Roots Room to Breathe!

When growing cannabis in containers, for example with soil or coco, it’s important to give your plant roots enough room to grow. If they run out of space, it will limit the size of your plant, and often causes nutrient deficiencies and other problems like persistent droopiness. If your roots have circled around the edges of the container, it is rootbound and should be transplanted to a bigger container immediately!

Plants don’t really get “rootbound” in hydroponics because the roots are being constantly bathed in a nutrient water solution that provides both nutrients and oxygen to all parts of the roots. However, if the reservoir is too small your plants will drink all the water before you can replace it!

Your cannabis plants need a grow medium! Hopefully, today’s tutorial will help you pick the perfect one for your needs!

You Might Enjoy the Following Growing Tutorials…

More About Various Grow Mediums

  • Yields
  • Bud Quality
  • THC Levels
  • CBD Levels
  • Smell/Taste
  • Density
  • Bud Color (How to Grow Pink or Purple Buds)
  • Glitter (Make Buds Sparkle with More Trichomes)
  • Bonus: What Determines Yields?

What medium makes the best home for your cannabis plants? Is it soil? Hydro? Coco? We'll tell you all about your options and which is the best all around!