GRODAN STRIP of 8 X 3″ CUBES (LARGE HOLE 36MM)

Description

GRODAN STRIP OF 8 X 3″ CUBES (LARGE HOLE 36MM) is the connected propagation rockwool block strip from Grodan featuring the large 36mm centre hole that accommodates chunky cuttings, established seedlings, and larger seed germination directly into the cube format. We have been recommending Grodan propagation products to UK growers since 2017 as the industry-standard stonewool substrate for professional propagation and early plant development.

Why Grodan Stonewool Is the Propagation Medium of Choice for Professional Growers

Grodan’s stonewool propagation cubes provide a growing environment that closely replicates the conditions plant roots thrive in during early development — high air porosity, consistent moisture distribution, and a chemically inert matrix that places no limitations on root development direction. The manufactured fibre structure creates a network of pores that holds moisture while retaining approximately 20% air by volume — the balance that prevents both overwatering and dessication while maintaining the oxygen levels that developing root tips require. The consistent, manufactured quality of Grodan stonewool means that every cube in the strip behaves identically, producing predictable propagation results across the full batch. The large 36mm hole in these cubes accommodates chunky stem cuttings that would be difficult to fit into standard-aperture cubes, as well as pre-germinated seeds and larger seedling plugs being transplanted into the cube format.

Preparation, Use, and Transplanting into Larger Growing Systems

Soak Grodan propagation cubes in pH-adjusted water (pH 5.5) or dilute rooting nutrient solution before use to displace the air in the pores and establish the correct moisture distribution. Do not squeeze or compress the cube — allow it to drain to the natural moisture level after soaking. Insert cuttings or seeds into the large 36mm hole and maintain in a humid propagation environment at 22–26°C. When roots emerge from the cube’s base and sides, the cutting is ready to transplant into a larger Grodan block, coco substrate, or hydroponic system. The strip format keeps cubes cleanly organised and prevents edge drying during propagation. Browse our full Grodan propagation range for cubes, blocks, slabs, and the complete stonewool growing system.