Premium Starter Rockwool Cubes for Seedlings & Cuttings

The BLOCK-Start 7.5cm² x 6.5cmH Rockwool cube is purpose-designed for reliable seedling propagation and early-stage rooting. Each cube comes with a centrally drilled 38mm wide by 35mm deep hole, ideal for accommodating seeds, plugs, or freshly rooted cuttings with minimal transplant shock.

Made from high-density, horticultural-grade Rockwool, these cubes provide the perfect balance of moisture retention and oxygen availability, encouraging rapid root development. This bulk case of 224 units is ideal for commercial operations or serious hobby growers running large-scale propagation cycles.

Key Features:

• Cube Dimensions: 7.5cm x 7.5cm x 6.5cm high

• Pre-Drilled Hole Size: 38mm diameter / 35mm depth – fits most propagation plugs

• Material: Clean, inert Rockwool – sterile and pH-neutral

• Optimised for Propagation: Promotes fast rooting and healthy early growth

• System Compatibility: Suitable for hydroponics, NFT, flood & drain, and more

• Bulk Pack: CASE of 224 blocks – ideal for scaling up propagation efforts

• 224 x BLOCK-Start Rockwool Cubes (7.5cm² x 6.5cmH) with 38×35mm holes

• Protective carton packaging for easy handling and hygienic storage

How to Use the Product & Best Usage Recommendations:

Before planting, soak the cubes in pH-adjusted water (ideally pH 5.5–6.0) for several hours to flush and stabilise the Rockwool. Once prepared, place seeds or rooted cuttings into the pre-drilled holes. For best results, maintain a humid environment using a propagation dome and gentle warmth to stimulate early root formation.

When roots emerge from the bottom or sides of the cubes, transplant into larger Rockwool blocks (such as Block-BIG 15x15x15cm) or directly into your chosen hydroponic system. Avoid oversaturation—Rockwool should be moist, not soaked.

Store unused cubes in a clean, dry place to maintain their sterile condition.