Grodan Grow-Cubes | 2cu ft - Large

Loose Stone Wool Fill Media, 2cu ft Retail Bag

Some growers need a loose stonewool material rather than pre-formed blocks, whether for filling odd-shaped containers or blending into another substrate. Grodan Grow-Cubes are loose stone wool pieces manufactured from the same engineered fiber as Grodan's block lines, meant to be used on their own or mixed into another growing medium.

This 2cu ft size ships in a retail-friendly bag, sized for smaller jobs or garden centers stocking Grow-Cubes alongside other growing media.

Key Features & Benefits

• Loose Stone Wool Format — individual cubes rather than pre-formed blocks, for flexible fill or blending use.
• Same Engineered Fiber — manufactured from Grodan's hydrophilic stonewool, matching the water and air behavior of its block products.
• Use Alone or Blended — works as a standalone growing medium or mixed into another substrate for added aeration.
• Retail or Bulk Packaging — available in a smaller retail-friendly bag or a larger loose-cube format for bigger jobs.

Who Should Use Grow-Cubes

Growers who want a loose stone wool fill material, either as a standalone medium or blended into soil or coco for added aeration, are the fit for Grow-Cubes rather than a pre-formed Gro-Block.

About Grodan

Grodan has manufactured stonewool growing media since pioneering the process in 1969 and, as part of ROCKWOOL Group, extends that same engineered fiber into loose formats like Grow-Cubes alongside its pre-formed blocks and slabs.

Frequently Asked Questions

What are Grow-Cubes used for?

Grow-Cubes are loose stone wool pieces meant to be used on their own as a growing medium or blended into another substrate for added aeration and moisture retention. Growers pick the format based on whether they want a standalone medium or a soil amendment.

Can Grow-Cubes replace a Gro-Block?

They serve a different purpose — Grow-Cubes are a loose fill material rather than a pre-formed block, so they suit container fill and blending rather than the propagation-to-transplant sequence Gro-Blocks are built for. Growers who need that sequence should use the Gro-Block line instead.

How do I blend Grow-Cubes into another medium?

Mix loose cubes into soil, coco, or another substrate at the ratio your growing method calls for, then water the blend in to settle the mix before planting. Start with a modest ratio and adjust based on how the mix drains.

What's the difference between the 2cu ft and 5.07cu ft sizes?

Both are the same stone wool material. The 2cu ft size ships in a retail-friendly bag while the 5.07cu ft size ships as loose cubes in a box, suited to larger jobs.