Stone Wool Growing Trial

Zwaagdijk Research Center, a well known institute in the Netherlands, conducted a stone wool growing trial over several days, with several batches of tomatoes. The trial was run by an independent laboratory working with ISO 17025-accreditation. As a result of the trial the following conclusion was derived.

General Plant Quality

Throughout most of the crop growth, the plants grown in the SpeedGrow™ slab were better than the other two commonly known brands. The leaf color of the tomatoes were much greener and the leaves looked generally much healthier with Speedgrow™.

Yield Influence

While the Speedgrow™ Green slab produced the best plants out of the three, there was no significant difference in the yield.

Average Fruit Weight

At harvest, Speedgrow™ Green and one of the other slabs had a significantly higher fruit weight over the third slab. The result was consistent between the 3rd and 4th truss and the 5th and 6th truss.

Root Development

Between the three different slabs there were noticeable differences in the root development. Speedgrow™ Green had roots throughout the slab while the others mainly had roots confined to the top of the slab. At the end of the trial, Speedgrow™ Green’s roots were lighter in color and looked abundantly healthier than the others.

See for Yourself

Which one is the best rooted stone wall slab?

SpeedGrow roots compared to competitors. Speedgrow shown in the middle. Stone Wool Growing Results.
Speedgrow™ Green slab shown in the middle.
Speedgrow Green Soil Retention Curve - Stone Wool Growing Results.

Stone Wool Growing Trial

Zwaagdijk Research Center, a well known institute in the Netherlands, conducted a stone wool growing trial over several days, with several batches of tomatoes. The trial was run by an independent laboratory working with ISO 17025-accreditation. As a result of the trial the following conclusion was derived.

General Plant Quality

Throughout most of the crop growth, the plants grown in the SpeedGrow™ slab were better than the other two commonly known brands. The leaf color of the tomatoes were much greener and the leaves looked generally much healthier with Speedgrow™.

Yield Influence

While the Speedgrow™ Green slab produced the best plants out of the three, there was no significant difference in the yield.

Average Fruit Weight

At harvest, Speedgrow™ Green and one of the other slabs had a significantly higher fruit weight over the third slab. The result was consistent between the 3rd and 4th truss and the 5th and 6th truss.

Root Development

Between the three different slabs there were noticeable differences in the root development. Speedgrow™ Green had roots throughout the slab while the others mainly had roots confined to the top of the slab. At the end of the trial, Speedgrow™ Green’s roots were lighter in color and looked abundantly healthier than the others.

See for Yourself

Which one is the best rooted stone wall slab?

SpeedGrow roots compared to competitors. Speedgrow shown in the middle. Stone Wool Growing Results.
Speedgrow™ Green slab shown in the middle.
Speedgrow Green Soil Retention Curve - Stone Wool Growing Results.