Pargro Rockwool Blocks | Large - 4in x 4in x 4in with Hole - Carton

Full-Depth Value-Tier Rockwool Block for Vegetative Root Volume, 4x4x4in Carton

A young plant that has filled a small propagation cube still needs a full-depth block to keep building root volume before it ever reaches a slab, without paying premium-block pricing for that stage. Grodan's Pargro Rockwool Blocks in the 4in x 4in x 4in Large size ship dry to keep freight costs down, re-wet quickly once soaked, and arrive with a factory-cut hole ready for a rooted plug.

This Large block ships boxed in a carton of 144, a format suited to growers who want blocks pre-boxed rather than loose on a pallet.

Key Features & Benefits

• 4in x 4in x 4in Large Format — a full-depth block sized for vegetative root development after propagation.
• Pre-Cut Hole — sized to receive a rooted plug or smaller propagation cube.
• Dry-Shipped, Value-Tier Rockwool — ships dry to hold down freight costs, then rehydrates fully within a normal soak cycle.
• Loose Pallet or Carton Packaging — available in either format to match a grower's order size and handling preference.

Who Should Use Pargro Large Blocks

Growers who want a full-depth, value-priced rockwool block for the vegetative stage, without the per-unit cost of a premium engineered block, are the fit for Pargro Large Blocks.

About Pargro Rockwool

Pargro is Grodan's value-tier stone wool line, made in standard sizes for a range of growing setups and priced below the company's premium Improved Gro-Block series.

Frequently Asked Questions

What does 'value-tier' mean for the Pargro line?

Pargro ships dry rather than pre-soaked, which lowers freight weight and per-unit cost compared to Grodan's premium Improved Gro-Block series. Growers rehydrate the blocks on-site before transplanting rather than using them straight out of the box.

How do I prepare a Pargro Large Block before use?

Soak the block in pH-adjusted water until it's fully and evenly saturated, since it ships dry. Once rehydrated, set a rooted plug or smaller propagation cube into the pre-cut hole.

What's the difference between the loose pallet and carton packaging?

Both are the identical 4in x 4in x 4in block with the same pre-cut hole. The difference is only in how they ship — loose on a bulk pallet for larger orders, or boxed in a carton for smaller ones.

When should a plant move into a Large Pargro Block?

Move a plant into a Large block once it has outgrown a smaller propagation cube and needs more root volume for continued vegetative growth. It's a common step before a plant goes onto a full slab.