Recommended for long-term crops such as tomatoes and cucumbers and for direct seeding baby salad greens and herbs. Special Features: • Slabs are encased in a plastic sleeve which blocks algae, prevents heat build-up and reduces evaporation. • Seedlings and cuttings an be started in STG™ Grow Cubes and Blocks and transplanted into Slabs or can be started directly in STG™ Grow Slabs. • Compatible with STG Flood and Drain Mats.