Grodan IMPROVED Gro-Blocks 4″X4″X2.5″

a { text-decoration: none; color: #464feb; } tr th, tr td { border: 1px solid #e6e6e6; } tr th { background-color: #f5f5f5; } Grodan Stonewool (Rockwool) Growing Blocks What is Grodan? Grodan Stonewool is a premium hydroponic growing medium made by melting natural rock and spinning it into fine fibers, similar to cotton candy, before forming it into cubes, blocks, and slabs. Unlike many rockwool products, Grodan designs different fiber structures for different plant growth stages, helping maintain the ideal balance of moisture and oxygen around the roots. Why Growers Love Grodan Excellent water-holding capacity. Maintains high oxygen levels around roots. Encourages rapid root development. Clean, sterile growing medium. Consistent results from crop to crop. Ideal for hydroponic and drip irrigation systems. Easy transplanting from cube to block to slab. Suitable for vegetables, herbs, ornamentals, tropicals, and cannabis. What Do You Do With It? Starting Seeds Soak cubes in properly pH-adjusted water. Place seeds in the pre-made hole. Keep warm and moist. Roots develop quickly thanks to the ideal air-to-water ratio. Rooting Cuttings & Clones Insert fresh cuttings into Grodan cubes. Place under humidity domes or clone lighting. Maintain humidity and proper temperatures. Watch for rapid root development. Growing Larger Plants Place small cubes into larger Grodan blocks. Blocks can sit directly on Grodan slabs for expanded root volume. Feed using hydroponic nutrients through drip irrigation or hand watering. Grodan Delta Blocks Grodan Delta Blocks feature: Uniform structure for consistent growth. Grooved bottoms for improved drainage. Various sizes for different crops. Compatibility with AO plugs and starter cubes. Suitable for direct seeding and transplanting. Grodan Hugo Blocks The largest Grodan growing block available. Benefits: Supports larger plants. Provides substantial root volume. Often eliminates the need for a slab underneath. Popular for high-value crops and large fruiting plants. Great For Cannabis Tomatoes Peppers Cucumbers Lettuce Herbs Houseplants Tropical plants Cloning Seed starting Commercial greenhouse production