Growing Media: How to Pick

Growing Media: How to Pick

Keith
Keith
08 Mar 2019

Your growing media is very important. It impacts plant growth and governs the other purchases you will make.

To pick a growing media, you need to think about:

  • Your growing system
  • Drainage vs. water retention
  • Inert vs. nutritional content
  • Results vs. ease of use

In general, you’ll need to choose between soil, coco & hydro medias. Then you just pick a propagation media that suits your final choice.

1. Pick a Media to suit your Growing System

First, your media needs to suit your system.

In hydro systems, you need a media that drains well so you’re not water-logging plants. One that won’t cause blockages in your system. Stay away from anything that can travel through your system and cause blockages.

However, if you’re hand-watering, you want a media that holds onto water. That way you can feed less often.

Media to suit your system Media to suit your system
  • Soil medias: hand-watering, drip irrigation, AutoPots, RhizoSystems
  • Coco medias: hand-watering, drip irrigation, AutoPots, RhizoWilmas, RhizoSystems
  • Rockwool: NFT, drip irrigation
  • Pebbles: Oxypots, Flood & Drain, Ebb & Flood, DWC, NFT

2. Drainage vs water retention: get your media structure right

Some growing medias drain better than others.

The one you want depends on your irrigation strategy. In flood & drain systems, for instance, you irrigate often, so want a nice, porous media that drains well.  

Drainage vs. Water Retention Drainage vs. Water Retention
  • Holds water: Coco, soil, rockwool
  • Drains well: Clay pebbles, perlite

Don’t be afraid to mix medias together. Lots of people mix pebbles or perlite in with their coco or soil to increase drainage.

  

3. Do you want a media with nutritional content?

If your media contains nutrients, you don't have to feed as often. If your media is inert (no nutritional content) then you have more control over what plants consume. 

Nutritional Content Nutritional Content

Soil

Soil naturally contains nutrients and beneficial microbes. These help keep plants healthy and ward-off pathogens. If you’re growing organically, soil is a great choice! Most organic nutrients work with the beneficial microbes already in your soil – like Ecothrive ChargeBiosys, Mykos & more. BioBizz is a great soil nutrient.

Nutritional Content Nutritional Content

Coco

Coco is an awesome media with some very unique properties.

100% coco

Like hydro medias, it’s inert, giving you greater control of your feed.

Coco also has a calcium draw. This is where it holds on to calcium, making it unavailable to plants. To counter this, coco nutrients are higher in calcium. To be safe, use a good CalMag supplement.

Coco Media Mixes

If you want some nutritional content, try a pre-fertilised coco mix. For instance, Ecothrive Coco and TropicMix 70/30 contain Ecothrive Charge. Both mixes contains bacteria and microbes that keep plants healthy. You’ll notice root grow sooner, are more resistant to diseases. You won’t have to feed as often, either.

You can also get some interesting coco/clay mixes, which improve drainage!

Pick a Quality Coco

Make sure you buy a quality coco, like the ones we sell. Inferior coco may contain salts, due to the way the coco is washed and treated. These salts can affect the way plants absorb nutrients – they can cause nutrient lockout and even be toxic to plants. 

Nutritional Content Nutritional Content

Hydro medias

Hydro medias are always completely inert. They have no nutritional content whatsoever. This way you have total control over what nutrients your plant is getting. Commercial growers, who need consistent and predictable results, love this method.

4. Do you need a forgiving media or better results?

If you’re a beginner, start with a more forgiving media, like soil or coco. For better potential results, pick a hydroponic media.

Do you need a forgiving media or better results? Do you need a forgiving media or better results?

Soil

Soil is the most forgiving media. It buffers your pH and already contains nutrients. The microbes in soil help fight of pathogens, so root rot is less of a risk. Since roots are insulated by media, you don’t have to worry as much about temperature changes affecting roots.

Do you need a forgiving media or better results? Do you need a forgiving media or better results?

Coco

Like in soil, roots are insulated to offset temperature changes. Coco is inert and is known for having a light, airy structure which is great root growth. It doesn’t compact like soil sometimes does. With a media like this, you can get excellent results. If you want it to be a bit more forgiving, opt for a pre-fertilised mix.

Do you need a forgiving media or better results? Do you need a forgiving media or better results?

Hydro medias (pebbles, perlite, rockwool)

The difference between each hydro media can be huge.

Hydroponic growing medias aren’t very forgiving.  They don’t hold as much water as soil or coco – this means you need to irrigate often. But something like rockwool holds more water than clay pebbles.

In DWC or NFT systems, your hydro media is used more to keep plants upright – they don’t actually insulate roots at all. You get crazy results in hydro though. You get bigger roots in less time. There’s no media to restrict nutrient uptake or slow root growth. Results are incredible.

5. What propagation media do you need?

Your propagation media needs to suit your final media.  Most growers use jiffy plugs, root riot or rockwool blocks.

Propagation media Propagation media

Jiffy plugs + root riot

best in: soil or coco

They are soft, so can break apart. In soil and coco, this is fine.  In hydro medias, it’s not good. They don’t offer enough support to plants. And you don’t want bits of jiffy pellet clogging up your system.

Propagation media Propagation media

Rockwool blocks

best in: hydro

Like in soil, roots are insulated to offset temperature changes. Coco is inert and is known for having a light, airy structure which is great root growth. It doesn’t compact like soil sometimes does. With a media like this, you can get excellent results. If you want it to be a bit more forgiving, opt for a pre-fertilised mix.

Picking a media isn’t straightforward. There are a lot of pros and cons to each one. Visit a shop or get in touch if you want us to work out which media is best for you.

Keith
Keith
About the author

Keith looks after our stock and staff. He's a bit of a hippie and has the hots for chillies. If you want to grow them, ask Keith how it's done.

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