Grodan Transplanting Cubes

Step rooted plugs up without stalling growth

Grodan Transplanting Cubes are dibbled stonewool blocks sized to sit between a small propagation plug and a full slab, pot or hydroponic system. Available as 3 inch (7.5 x 7.5 x 10 cm) or 4 inch (10 x 10 x 10 cm) cubes with a small or large planting hole, they give a rooted cutting or seedling more root volume to grow into before its final move. Dropping a young plug straight into a full slab leaves roots swimming in more water and medium than they can use, and growth pauses right when it should accelerate; a transplanting cube keeps root volume matched to demand so plants keep motoring on.

Key Benefits

• Sized step-up - bridges the gap between starter plugs and full-size slabs or 15L pots, cutting transplant shock
• Two hole options - small or large pre-cut hole to seat 1.5 inch or larger propagation plugs snugly with no air gaps
• Engineered air-to-water balance - Grodan stonewool holds roughly 80% air porosity when drained, keeping oxygen at the root zone
• Uniform structure - consistent density makes watering and feeding predictable and repeatable across a whole batch
• Clean, inert medium - pH-neutral stonewool with no pests, weed seeds or nutrient content, so you control the feed entirely
• Grow-through convenience - transplant the whole cube on once roots emerge, with zero root disturbance

Beat transplant shock and stalled root development

The main cause of a growth check after potting up is a mismatch between root mass and medium volume - too much wet substrate around too few roots. Stepping through a transplanting cube keeps root development in step with the medium on offer, so plants grow on steadily instead of pausing to recover.

How to Use

• Soak before use: submerge cubes in pH 5.5 to 6.0 water for at least an hour to condition the stonewool and remove excess alkalinity
• Seat the plug: push the rooted cutting or seedling firmly into the pre-cut hole, matching hole size to your plug for full contact
• Water in: feed gently with a mild nutrient solution at EC 1.2 to 1.5 and keep the cube moist but not saturated
• Grow on: once white roots show through the base and sides, transplant the whole cube into its final slab, pot or system
• Tip: never let cubes dry out fully, and avoid overwatering early - the stonewool should feel damp, not swimming