Grodan Stonewool Delta Starter Blocks

No, the white plastic wrapping is designed to stay on the block during the entire propagation process. It helps maintain the block's structure and prevents algae growth, so you can transplant the entire unit directly into your larger medium.

Yes, Grodan Delta Mini-Blocks are specifically engineered to support both seed germination and the rooting of cuttings. Their structure provides an ideal balance of moisture and aeration for early root development.

Because the blocks are individually wrapped and come in tear-away strips, you can easily separate them once roots have established. You can then place the entire block directly into loose potting media or nestle it into a larger Grodan Gro-block.

The 1.5-inch blocks are ideal for smaller seeds or quick-rooting cuttings, while the 2-inch blocks offer more volume for plants that need a slightly longer stay in the propagation phase. Choose based on the size of your plant and how long you intend to keep it in the starter block before the final transplant.

Stonewool is naturally inert, so it is best practice to soak the blocks in a pH-adjusted nutrient solution before inserting your seeds or cuttings. This ensures the medium is properly hydrated and at the correct pH level for immediate root uptake.