Grodan

Grodan is the world's leading manufacturer of stone wool (rockwool) growing media for professional and home hydroponic cultivation. Made from volcanic rock spun into fibres, Grodan substrates provide optimal air-to-water ratios for explosive root development, and are sterile and pH-stable from the bag, with no soil-borne pests or pathogens to manage.

For seed germination and taking cuttings, Grodan 40mm Rockwool Cubes are the most widely used starter plug format in commercial hydroponics globally. Once cuttings or seedlings have outgrown a starter cube, Grodan 75mm Cubes (No Hole) give a genuine step up in root zone volume, with full control over cutting placement and seed depth. For consistent, repeatable results across every plant in a tray, Grodan 75mm Cubes (With Hole) come with a pre-formed hole for standardised placement and insertion depth.

Suitable for NFT, DWC, drip, and media-based hydroponic systems. Trusted by commercial greenhouse growers worldwide. Fast shipping across Australia.

Frequently Asked Questions

Do I need to soak Grodan rockwool cubes before use?
Yes. Pre-soak cubes in pH-adjusted water (around 5.5) before sowing seeds or inserting cuttings, since dry rockwool has a naturally high pH that can affect early root development.

What's the difference between the 40mm and 75mm cubes?
The 40mm cube is the standard starter size for seeds and fresh cuttings. The 75mm cubes provide more root zone volume for plants that have outgrown a starter cube and need room to develop further before transplanting.

Is Grodan rockwool reusable?
Rockwool is generally treated as single-use per plant, since root structure and any residual salts remain in the cube after harvest, but the material itself is inert and won't introduce disease if properly sourced.

Does Grodan ship fast within Australia?
Yes. All products ship from our Australian warehouse with fast tracked delivery Australia-wide.