Grodan Improved Gro-Block

Grodan Improved Gro-Block

Grodan Improved Gro-Block

The new and improved stone wool substrate with advanced wetting technology from Grodan

Introducing Grodan Gro-Blocks Improved, a product specifically engineered to deliver actual 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 allows 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 root zone due to the uniform, optimized wool resulting in sustainable water and nutrient use. Improved “re-wettability” able to more easily increase water concentration in the substrate.

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 throughout 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 result 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.

Wrapped Vs Unwrapped: The blocks that are marked 'wrapped' in the product name indicate they come wrapped in the plastic covering shown in the image. Those marked 'unwrapped' come without any plastic wrapping (not shown)

Key Benefits of Grodan Gro-Blocks Improved
Excellent Control

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

Greater steering possibilities

The advanced technology used in Grodan Gro-Blocks Improved combined with the uniformity of WC and EC throughout the entire block providing 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.

Roots making better use of the 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 stage 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.

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.


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 them soaking for extended periods of time.

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 block Grodan White Jumbo and Grodan White Hugo Gro-Blocks – insert 2 drip stakes per block. The 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):

Weight (lbs)28.20
Length (in)24.3
Width (in)16.3
Height (in)24.2

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