Eco-preneurs, Andrew Ungerleider and Gay Dillingham

History of Growstone

In response to the destructive pumice strip-mining they saw taking place in Northern New Mexico’s Jemez Mountains, eco-preneurs Andrew Ungerleider and wife, Gay Dillingham, researched and brought foamed glass technology to the US. Together they saw an opportunity for replacing these strip-mined products across many industries. Their work resulted in a number of alternative products to the commonly used, strip-mined hydroton and perlite by creating foamed glass from recycled bottle glass.

Working with Dr. Gene Giacomelli, Director of the Controlled Environment Agriculture Center at the University of Arizona, and then graduate student, Paula Costa (now Dr. Paula Costa, our Director of Research and Development at Growstone), they explored the potential of a “rigid foam glass” as a new substrate for hydroponic production.

Commercial growers - Paula- GS vs. stonewool_Tomato trial at WUR_Holland_2007

Dr. Paula Costa, Director of R&D at Growstone and Chris Blok, Project Manager at Wageningen University Research, Greenhouse Horticulture, checking Growstone greenhouse trial comparing tomato plant growth and yields between Growstones and rockwool in 2007, Netherlands.

What they discovered was nothing less than revolutionary. A sustainable growing medium that wicked water fast, retained a relatively large amount of water after readily draining the excess, was easy to rewet after being dry, and had a very high air filled porosity even after irrigation. This new and highly steerable aggregate base substrate became known as Growstone.

Between 2006-2009, Growstone’s were used in multiple commercial-like greenhouse trials. All trials confirmed the high performance capacity of Growstone for hydroponic crop production. 

Along with a founding group of investors, Andrew then approached the City of Albuquerque to take the discarded bottles in New Mexico’s landfills for Growstone production. “We like to say that instead of mining the Earth, we mine the landfill,” says Andrew. Today, Growstone takes over 250 tons of discarded glass bottles out of New Mexican landfills each month and turns them into high-performance horticulture products for the hydroponic and garden markets.

We’re growing a revolution!