VIVOSUN Rockwool Cubes 1.6" Seedling Plugs, 8 Sheets (224 Plugs) — High Porosity, Sterile Starter Medium

VIVOSUN 1.6" Rockwool Cubes are sterile, high-porosity stonewool starter plugs sold as 8 perforated sheets (28 plugs each) designed for seed starting, propagation, and hydroponic cloning.

These rockwool cubes provide a consistent, inert medium engineered to promote quick root development and reliable moisture retention. Each 1.6-inch cube is formed from spun basalt- and limestone-based fibers, compressed into reusable sheets that are easy to split, insert seeds or cuttings into, and transfer to larger media or net pots as roots establish. The pack contains 8 sheets, totaling 224 plugs—suitable for hobbyists, small growers, and commercial propagation setups.

How do these cubes help seedlings and cuttings get established?

The open fiber structure and 95% porosity let roots access oxygen while holding water evenly around the plug. This balance reduces transplant shock and supports uniform root branching, making early-stage growth more predictable.

• High porosity for oxygenated root zones
• Even moisture retention to prevent drying and overwatering
• Pre-formed holes sized for seeds and typical stem cuttings
• Uniform plugs improve germination and clone success rates

What are these rockwool cubes made of and are they safe to use?

These plugs are manufactured from natural mineral inputs—roughly basalt, coke, and limestone—melted and spun into fine fibers, then compressed into solid cubes. The final product is inorganic and sterile, so it won’t introduce soil-borne pests or pathogens to young plants.

• Composition: basalt, coke, limestone, trace iron slag
• High-temperature manufacturing for consistent fiber structure
• Inorganic, sterile medium—no soil-borne microbes included
• Suitable for organic systems when used per local guidelines

How do I use and handle the sheets during propagation?

Each sheet is light and easy to work with: separate or cut cubes to size, place seed or cutting into the pre-made hole, then keep humid and watered until roots fill the plug. When roots are visible and strong, you can transplant the entire plug into larger media or a hydroponic net pot without disturbing roots.

• Cut or split cubes to fit trays or net pots
• Insert seeds/cuttings into molded holes for stable positioning
• Keep in humidity dome or mist frequently for best rooting
• Transplant plug whole to reduce shock once roots appear

Will these plugs work in hydroponic systems and soil transfers?

Yes—rockwool excels in hydroponic reservoirs, ebb-and-flow, and NFT, and it also simplifies transfer to soil or coco once roots are established. Its water retention and sterility make it a versatile bridge medium between propagation and production systems.

• Compatible with most hydroponic setups and grow trays
• Works as a plug for net pots and cloners
• Eases transplant into soil or larger containers with minimal root disturbance
• Pack size supports multiple propagation cycles

Who is this for? Growers who want fast, predictable propagation—whether you run a small home grow, a hobby greenhouse, or a larger hydroponic bench—will value the consistency and sterility of VIVOSUN 1.6" Rockwool Cubes. The 224-plug kit is especially handy for anyone scaling up cuttings or starting many seeds, and for growers who prefer an inert, oxygen-rich medium that’s simple to handle and transplant.