Which Grow Media Are Best for Growing Cannabis?
You’re here for an answer, and you’ve come with a great question, but the answer is, unfortunately, not so simple! Like most things, our best quick response to such a question is “it depends!” In this article we’ll break down the pros and cons of every grow medium we have used throughout our years of growing. We think you’ll find this a useful, quick guide to selecting the perfect growing media for your indoor grow. First, we’ll define all the media we’ll speak about and then we’ll give a pros and cons list.
Potting Soil
You’re probably familiar with potting soil. It is mainly made from a mixture of peat moss, bark (usually a deciduous tree), and some type of aerating substance like perlite or vermiculite. You’ll be able to find potting mix pretty much anywhere you shop for gardening supplies and it is a tried-and-true way of getting good results.
Coco Coir
We covered coco coir in detail in another article so we’ll briefly touch on it here. Essentially, coco coir is a soilless medium that is totally inert and retains water very well. Coco coir is extremely sustainable because it is a biproduct of coconut processing – when factories extract juice and meat from coconut they also have a lot of coconut waste left over, but this waste, the fibrous substrate of coconuts called coir, is extremely useful for both hydroponics and traditional growing.
Perlite
Perlite is a mineral that comes from volcanoes, a silicate that is processed at high temperatures to it turns into a light substance that takes up space in soil and allows for water to pass through, ensuring that your soil doesn’t retain too much moisture, which can cause some problems with bacteria, etc.
Peat Moss
Peat moss is essentially decayed plant material that retains water very well. It has naturally low pH levels so adding nutrients to it won’t have a bad impact on plant growth.
Vermiculite
Like perlite, vermiculite is a substance that helps improve drainage yet it also retains water well. It is a great addition to either coco coir or potting soil but shouldn’t be used by itself.
Outdoor Soil
Easy to get but really bad for growing plants indoors because outdoor soil contains a lot of bacteria and fungus. It’s important to not use soil from outside to grow indoors because plants that are delicate may die from pathogens.
Pros and Cons of Different Media
Type Pros Cons
Potting soil · Easy, familiar to use
· Good drainage
· Contains nutrients
· Contains elements for drainage
· Will need to watch TDS levels as adding nutrients can cause pH levels to rise uncontrollably
· Will need to flush the soil occasionally
Coco coir · Inert medium
· Excellent water retention
· Great growing results
· Can be recycled and used multiple times
· Very sustainable
· Very cheap compared to other media
· Works with hydroponics
· You may need to clean it when you buy it because it may be treated in salt water
· You’ll need to add nutrients
· You’ll need to add drainage materials like vermiculite or perlite
Perlite · Great addition to any media
· Helps improve drainage
· Cannot be used independently
· Can be expensive
Peat moss · A great addition to most media
· Naturally low pH levels so its great for tomatoes, strawberries, and other acid-loving plants
· Not suitable for all plants
· Retains a lot of water so it needs help with drainage
Vermiculite · Great addition to soil
· Helps drain and retain water
· Cannot be used independently
Outdoor soil · Essentially free
· Perfect for plants that grow outdoors
· Carries pathogens
· Can be dangerous to plants that are not native to a region or that are fragile
· May contain toxins
· Not a good choice for indoor growing!
If you have any questions, please don’t hesitate to reach out to us!
And be sure to check out our other blog posts for useful tips on becoming a great grower!