There are so many options for growth medium out there and so many different opinions about which one is best that it can be bewildering. The bottom line is – and let’s get this out of the way right from the start – if it works for you: go with it. This approach does involve some trial and error, so to get you off on the right foot we have prepared this little guide to the top three. Please note that this does not include growth mediums for aeroponic systems, this information will be published in a different article.


Rockwool is one of easiest growth mediums to start with; it is cheap and simple to prepare. Rockwool is made by superheating rock and steam blasting in to create a network of fibres once the material has cooled. This structure creates an absorbent and aerated material that your new roots will travel through.

You will need to soak your Rockwool in water that has been adjusted to a Ph of 5.5. This is done because Rockwool is slightly acidic and if used without adjustment will kill your cutting roots.

6-Inch Large-Hole (1") Hugo Block Rockwool Cube
Root ot Grodans 36/77 cube

Starter Cells

Rooting plugs are similar to Rockwool, but instead of being made of superheated stone, they are made of organic material and will come pre-soaked. They are a far more natural material and will hold plenty of water whilst providing enough aeration to promote healthy root growth in your cuttings.

Root plugs are easier to manage than Rockwool as they are designed for the job, where as Rockwool has been adapted from the construction industry. However, rooting plugs can be more prone to disease and because they are designed to retain nutrients, over feeding will have devastating effects.

Also, starting your cuttings in starter plugs will get you plants used to an organic base, so you might want to think about planting out in a soil based medium.

Alternatively, cuttings rooted in Rockwool will be more used to a mineral environment so planting out into clay or pebbles makes the most sense.

Root-It Fleximix Plugs - Tray of 24

Clay Pebbles & Coco Mix.

Clay pebbles have a rough surface which is good for roots to bind onto, and their porous structure means that they will hold water effectively. They are pH neutral and provide a stable growing environment. However, for best results, we recommend a clay pebble and coco mix to create and environment that will generate the best root growth whilst minimising the risk of root rot by providing good drainage.

Coco Coir is a new addition to the growing scene and is basically the fibre from coconut husks. By mixing it with clay pebbles, your plants will generate a stronger initial root structure which will generate more vibrant and higher yielding mature plants.

Canna Coco Natural
Canna Clay Pebbles

Getting the growth medium right is going to give you stronger plants. We have covered three basics here for standard growing, but there are always other options. Different brands will produce different results and the the of system you are using will also have an effect.

We hope you’ve found this blog useful.

Drop us a message or call through on 01924 492298  and we can help you!

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Happy Growing.