Stonewool is recognized the world over as an ideal hydroponics growing
medium. Seeds or cuttings are started in these larger Grodan Gro-Blocks
and, once rooted, the blocks are transferred to a larger stonewool
slab. Gro-Blocks can also be planted directly into containers for soil
gardening. This is a strip of six 4"x4"x2.5" Gro-Blocks, each with
pre-formed holes. Grodan stonewool is known for its quality,
consistency and performance.