Grodan Gro-Block Improved

Grodan Gro-Block Improved


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Grodan Brand Product
$166.40 - $1,356.82

Lead time: Please select an option below


New and improved stone wool substrate with advanced wetting technology from Grodan

Introducing Grodan Gro-Blocks Improved, a product specifically engineered to deliver real results for your crops, developed by plant scientists, researchers, and top growers.

A core component of the "Precision Growing" philosophy, Grodan Gro-Blocks Improved with Advanced Wetting Technology allow you to cultivate more uniform and high-quality crops while using less water and nutrients.

The uniform distribution of water and nutrients throughout the block allows for more efficient use of the entire substrate volume. Full saturation of the blocks with no dry spots and improved EC control with less water is achieved in the rootzone due to the uniform, optimized wool resulting in a sustainable water and nutrient use. Improved “re-wettability” able to more easily increase water concentration in the substrate.

Gro-Blocks Improved

Real Improvement

These leading-edge blocks have the optimal fiber structure and physical properties for crop uniformity, more even Water Content (WC) and Electrical Conductivity (EC) distribution throughout the entire block, and the greatest steering capabilities available. Water distribution is more uniform throughout the entire block which is the basis for a well-defined root system with higher capacities for water and nutrient uptake to produce robust and vigorous crops.

Real Science

Grodan partnered with the Wageningen University and Research facility in The Netherlands and top growers through North America to identify the optimal stone wool substrate and irrigation strategies for specialty crops. The result of this scientific research and real-world trials is Grodan Gro-Blocks Improved

Real Results

The results of this scientific rigor is Grodan Gro-Blocks Improved with Advanced Wetting Agent. In the scientific, and local grower trials, plants grown in these new blocks has faster rooting-in, higher yields, improved quality, and less water usage throughout the entire crop cycle.

Options Available

  • Grodan Gro-Block Improved GR10 4 cu. inch - Pallet of 1,584 (Loose)

    Grodan GR-10 blocks are ideal for propagation of larger plants before transplanting onto a larger volume. The block is also a good choice for smaller plants or shorter crop cycles

  • Grodan Gro-Block Improved GR22 Jumbo 6"x6"x4" - Case of 64

    Perfectly designed to supposrt medium sized plants through to harvest. The Jumbo is also a great choice to transplant a smaller, well rooted Gro-Block

  • Grodan Gro-Block Improved GR32 Hugo 6"x6"x6" - Case of 64

    The ideal choice for most plants. The easy to use system was designed to accommodate the 1.5" Grodan A-OK Starter Plug and then support the plants growth through to harvest.

  • Grodan Gro-Block Improved GR32 Hugo 6"x6"x6" - Pallet of 512 (Loose)

Key Benefits of Grodan Gro-Blocks Improved

Excellent Control

Excellent Control

The improved initial saturation and improved water distribution throughout the height of the blocks results in improved root growth, enhanced water holding capabilities and more stable EC behavior in the root zone. This makes it is easier than ever before to control your crop, with even less inputs, from propagation through to harvest.

Greater Steering

Greater steering possibilities

Advanced technology used in Grodan Gro-Blocks Improved combined with the uniformity of WC and EC throughout the entire block provide better vegetative and generative steering. WC and EC can be adjusted more rapidly and efficiently. This offers additional assurances, such as in the case that the grower would need to adjust root zone WC or EC.

Improved Roots

Roots making better use of entire substrate volume

Both the rooting-in and rooting-through plant processes have improved. Trials have repeatedly shown that the initial rooting-in phase in Grodan Gro-Block Improved occurs several days faster, speeding up the vegetative phase and time to harvest. The more effective rooting-through of the entire substrate volume leads to a visible increase of roots and thus, better water and nutrient uptake. Naturally, this results in enhanced plant health and productivity from start to finish.

Improved Plant Development

Stronger, more vigorous plant development

Due to the better developed root system in Grodan Gro-Blocks Improved, the trial results showed improved plant growth, including larger plant size, greater stem thickness and bigger leaves. Ultimately, this can lead to higher yield, while at the same time the stronger, more vigorous plants show increased resistance to disease.

Usage Example

Saturate the blocks

Saturate Grodan Gro-Blocks in a nutrient solution of roughly 1.5 EC and 5.5 pH with a course spray or submerged in the solution for up to 2 minutes. Do not over saturate the blocks or leave soaking for extended periods of time.

Measure Weight

Measure wet weight
Measure the weight of the block at saturation. Compare this weight to the weight of the blocks throughout the growing cycle. When the WC of the block is 55% to 65% apply the first irrigation.


Insert the well rooted Grodan Starter Plug into the hole of the saturated Gro-Block


We recommend using a pressure compensated drip irrigation system.Grodan White GR-4 and Grodan White GR-10 Gro-Blocks – insert 1 drip stake per blockGrodan White Jumbo and Grodan White Hugo Gro-Blocks – insert 2 drip stakes per block.Volume of irrigation should be 3% to 6% of growing media volume (for example, Grodan White Hugo is 100 mL to 200 mL)Irrigation Volumes (suggested flow rate is 0.5 gph (2 lph):

Tech Specs