G-Star Raw’s Greenhouse-Grown Cotton: Study Results and Next Steps
Does the answer to greener cotton cultivation lie in greenhouses? A study by G-Star Raw along with Wageningen University Research and Dutch Cotton put this hypothesis to the test.
The Sustainable Greenhouse-Grown Cotton research project explored the efficacy and impact of growing cotton indoors, including yield and environmental footprint. Researchers developed greenhouse facilities that are well-suited to cotton growing, including climate control and irrigation systems. They then planted and grew cotton using sustainable practices such as protecting biodiversity and soil health.
While this approach to cotton production is unconventional, the industry needs out-of-the-box thinking to tackle some of the toughest environmental concerns. “Innovation and sustainability are themes that are so deeply embedded in our DNA, and the beauty about this research is that the two come together, so we didn’t have to think for a second,” said Rebecka Sancho, head of sustainability at G-Star. “Research like this really allows us to rethink the entire way the industry is set up which is exactly what we need to do in order to truly improve our impact together.”
Growing cotton indoors offers plants more protection than they would receive in a field—including shielding crops from inclement weather. It also keeps harmful pests away without the use of pesticides. “We introduced beneficial insects on the plants, along with banker plants, as biological pesticides in the greenhouse environment to naturally control pests and promote plant health,” said Rebecka.
There is also more climate control, allowing for the most ideal growing temperatures and allowing for year-round planting. The result is a greater yield and therefore more efficient land use. The most successful plants in the study produced 1.2 kilograms of cotton per square meter, a figure up to 23 times greater than average conventionally grown plants.
When it came time to harvest the plants, the researchers turned to purpose-built solutions. “We used specialized, smaller-scale harvesting equipment designed for greenhouse use to pick the cotton and electrical vehicles for working with high wire plants, ensuring efficient and careful collection without damaging the plants,” Rebecka explained.
While a field-grown cotton plant would be uprooted during harvesting, the methods used in the greenhouse environment allow the plants to remain for multiple seasons. The oldest plants in the study were initially planted four years ago.
A key pillar of the project is measurement, including life cycle assessments and an evaluation of the economic ROI of greenhouse growing. Cutting down on emissions, greenhouse production allows for localized growing and minimal transportation. Meanwhile, irrigation systems allowed for more efficient water use, including recycling 35 percent of water used.
Not only is the cotton plentiful, but it has also met the quality standards set by G-Star Raw and its partners. The average fiber length is 30 millimeters, and Rebecka noted the crop’s “exceptional whiteness.” “We are confident that we can continue to maintain this quality,” she said.
This cotton was put into production as proof of concept. “With greenhouse-grown cotton in place, we joined forces with local suppliers to create the first-ever fully locally sourced and manufactured jean,” said Rebecka. “Every aspect of cotton processing and production of the garment was completed in the Netherlands from ginning to spinning, weaving, sewing, dyeing and finishing.
“It is a bit too soon to predict when exactly this cotton will be part of our collection since this first research was really the very first step, but by investing in the next phase we definitely aim for this to be part of not only our collections but of denim brands worldwide,” she added.
With the “promising” results in hand, G-Star Raw is moving on to the next phase of greenhouse cotton exploration focused on scaling production. A new crop is being grown in the greenhouse with returning collaborators Wageningen University and Research and Dutch Cotton, as well as new partners Inno Growers and Grodan. “In addition to optimizing growing methods, the primary goal here is to enhance cotton yield per square meter, aiming to increase it from 1.2 kilograms to 2.2-2.5 kilograms,” said Rebecka.
“With the right investment and expertise, greenhouse-grown cotton has the potential to scale to a commercial level,” she said. “The benefits of controlled growing conditions, resource efficiency and alignment with sustainability goals make it a promising avenue for the future of cotton production.”