Grodan Delta Gro-BlocksThe Foundation for uniform and perfectly controllable propagation of plants. Details Grodan Delta is the basis for an easy to steer propagation process, that results in uniform, good quality plants. Each block guarantees uniform water and nutrient distribution. Grodan Delta scores high in saturation and firmness, which means it always performs well in highly mechanized propagation processes. Application Grodan Delta is a reliable propagation block for