Research & Field Trials

Growstone produces earth-friendly, high productivity horticultural products made from recycled glass. Understanding how valuable your plants are to you, we have teamed up with renowned Universities and Institutions to conduct research comparing Growstones with the most used substrates in the industry today. As such, Growstone is certain it is providing you with the right products. Below you will find technical bulletins from such research and field trials.


Technical Bulletins from University Trials


The Use of Growstones Recycled Glass as a Green Roof Media

Summary: Growstones revealed to be highly suitable for green roofs with the added advantage of being considerably lighter than any other green roof media tested so far. At field capacity, Growstones based media average bulk density was 0.50 g/cc, less than half that of commonly used green roof media today. Regarding resistance to freeze thaw cycles, drainage, water holding capacity, and plant growth Growstone based media was similar to all other media evaluated for green roofs.

The Pennsylvania State University, Department of Horticulture, Center for Green Roof Research, 2012


Summary of Hydroponic Greenhouse Trials

Summary: Growstone hydroponic medium produced yields similar to Rockwool in three greenhouse trials with tomato and cucumber in the US and The Netherlands. Tomato yields in Growstones and Rockwool reached 40 kg/m2 in a 5-month production period in Arizona, with no CO2 enrichment. In The Netherlands, tomato yields in Growstones outperformed Rockwool by 4% due to a higher incidence of blossom end rot.


Greenhouse Cucumber Cultivation on Growstone Grow Bags
Summary: Growstones are an effective sustainable alternative to Rockwool regarding yields, resistance to fungal diseases, and enhanced generative plant growth. Dutch cucumber growers that visited the trial preferred Growstones over Rockwool due to its drier nature, high steer-ability, ability to be steam sterilized, and its ease of use in various container systems.

Wageningen University Research Center (WUR). The Netherlands, 2006


Greenhouse Tomato Cultivation on Growstones Grow Bags                                                                                Summary: Growstones grown plants respond faster to environmental and EC changes compared with Rockwool. Because of its drier nature, Growstones are easily steerable, have shown as much as twice as lower susceptibility to BER and slowly releases silica into the root zone in a form plants can uptake.

Wageningen University Research Center (WUR). The Netherlands, 2007


Greenhouse Cultivation of Tomatoes on Growstone Bags (Arid Climates)
Summary: Total yields were above industry levels in all substrates with the added advantage of Growstones higher fruit quality with respect to Brix and eco-friendly disposal over Rockwool.

The University of Arizona, Controlled Environment Agriculture Center, Tucson, 2007


Efficacy of Growstone as a Filter Medium in Aquaculture Applications
Summary: As a recycled glass and having a large surface area to volume ratio, Growstone is a relatively better and more cost effective option compared to other bio-filers used in Aquaculture systems.

The University of Arizona, Environmental Research Laboratory, Tucson AZ, 2009


Growstone Research Partners
Growstone has teamed up with the following renowned Universities and Institutions.


Wageningen UR Greenhouse Horticulture, The Netherlands

The University of Arizona, Controlled Environment Agriculture Center, Tucson, AZ

University of Arkansas, Department of Horticulture, Fayetteville, AR

The University of Arizona, Environmental Research Laboratory, Aquaculture, Tucson, AZ

Department at Pennsylvania State University, University Park, PA

NYC Science Barge, New York, NY