Grodan Rockwool Propagation Cubes: Versatile Growing Medium for Seeds and Cuttings

These 40mm Grodan Rockwool Propagation Cubes provide an excellent growing medium for raising seeds and growing cuttings. Each cube features a dual-sided design, with a small indent on one side for cuttings or large seeds and a flat surface on the other for small seeds. Rockwool cubes promote healthy root growth and moisture retention in your plants, ensuring they grow strong and robust.

Features and Benefits

  • Uniform size and shape: Each 40mm x 40mm x 40mm Rockwool cube ensures equal distribution of water and air, supporting consistent plant growth.
  • Dual-sided design: Large seeds and cuttings fit perfectly into the small indent on one side, while small seeds can be easily placed on the flat side.
  • Excellent water retention: Rockwool cubes effectively absorb water and maintain a consistent moisture level, reducing the risk of over-watering or dehydration.
  • Optimal root growth: The porous structure of Rockwool promotes strong root development and reduces the chance of root rot or mould growth.
  • Reusable and eco-friendly: Properly sanitized, Rockwool cubes can be reused, limiting waste and promoting sustainable gardening practices.

How to Use

  1. Soak the Grodan Rockwool Propagation Cubes in water for a few minutes to ensure they are fully saturated.
  2. Allow excess water to drain from the cubes by placing them on a clean surface or in a tray.
  3. Choose the appropriate side of the cube for your seeds or cuttings: small indent for large seeds and cuttings, or flat side for small seeds.
  4. Insert the seed or cutting into the cube, ensuring good contact with the Rockwool material.
  5. Place the prepared Rockwool cubes in a humidity dome, propagator, or other suitable growing environment with adequate moisture and temperature controls.
  6. Monitor the moisture levels of the Rockwool cubes and water as needed to maintain optimal growth conditions for your plants.

Aqua Gardening Suggests These are Best For

Grodan Rockwool Propagation Cubes are suitable for various types of gardeners, including those with limited space or resources, hydroponic growers, and users looking for an eco-friendly alternative to traditional soil. These cubes are ideal for growing a wide range of plants, from vegetables and herbs to ornamental flowers and shrubs.

Click here to read our handy guide on germinating seeds with rockwool.


What are some benefits of using Grodan Rockwool Propagation Cubes for seed germination and cuttings?

Grodan Rockwool Cubes are known for their excellent water retention, air circulation, and sterility. They provide an optimal growing environment for seeds and cuttings, promoting faster, healthier root development and plant establishment.

How do I prepare the Rockwool Cubes before use?

Before using Grodan Rockwool Propagation Cubes, soak them in water for approximately 30 minutes to completely saturate the cubes. You may also want to adjust the pH level of the water to between 5.5 and 6.5, which is ideal for most plants.

Is it necessary to insert seeds or cuttings in a specific side of the Rockwool Cube?

Yes, it's important to use the correct side of the cube for a better result. One side has a small indent, designed for larger seeds and cuttings, while the other flat side is intended for smaller seeds.

How do I maintain optimum moisture levels in the Grodan Rockwool Cubes during propagation?

To maintain appropriate moisture levels, ensure that the cubes are kept slightly damp but not soaking wet. Monitor their moisture content regularly and water them as needed. Avoid overwatering, as excessive moisture can lead to rot and inhibit root growth.

Can I transplant the Rockwool Cube directly into soil or a hydroponic system after the seedling or cutting is established?

Yes, Grodan Rockwool Propagation Cubes can be planted directly into soil or a hydroponic system without removing the seedling or cutting from the cube. This reduces transplant shock and ensures a smoother transition for the plant.

Are Grodan Rockwool Propagation Cubes reusable or biodegradable?

Rockwool cubes are not biodegradable and typically are not reused for growing new plants. The fibrous nature of Rockwool makes it challenging to clean and reuse. However, they can be repurposed for other uses, such as insulation or soundproofing.

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