29 May 2024


Homegrown Denim

A black and white picture of cotton cartoons that are smiling with a home

At G-Star, we’re dedicated to pushing the limits of how denim is made, used and worn. As the base material for denim, cotton means everything to us. ‘Homegrown Denim’ is a pioneering experiment that explores the use of greenhouse-grown cotton to reduce the environmental footprint of cotton farming worldwide. It's all part of our mission to make the best denim possible. This starts with where and how cotton is grown, and follows right through the supply chain to the final product: G-Star denim jeans.


On our journey towards more sustainable denim we asked ourselves: what if we could grow cotton better, anywhere? Could we make denim with greenhouse cotton that is homegrown and processed, reducing or even eliminating the impact from growing, manufacturing and transporting cotton – and along the way optimize the entire cotton growing process? We teamed up with Dutch Cotton, a company that grows cotton in sustainable greenhouses, and Wageningen University & Research to find out.


For six months, we studied a crop of greenhouse-grown cotton plants at a research facility in Bleiswijk, the Netherlands. We examined quality, yield, and fiber properties, comparing its environmental footprint to traditional methods. Strategies like precision irrigation and renewable energy were explored for reducing impact, with economic viability and market potential also analyzed.
a picture of a bunch of cartoon flowers
“Our curiosity and drive for innovation led us to this partnership to study the feasibility of growing cotton in a greenhouse. This groundbreaking experiment could revolutionize cotton cultivation by severely decreasing water consumption and land use, eliminating chemical pesticides.”
Rebecka Sancho - Head of Sustainability G-Star


Overall, we discovered that growing cotton in a greenhouse provides a controlled and protected environment that boosts crop productivity and sustainability, and lowers the risks that come with outdoor growing.

Here are the top 8 benefits that we found:

  1. Increased Yields: Greenhouses boost cotton yield potential, with plants growing up to 4 meters tall and producing 5 to 23 times more cotton.
  2. Extended Growing Season: Controlled environments in greenhouses enable cotton harvesting until for longer than usual.
  3. Weather Protection: Greenhouse-grown cotton is cleaner and whiter, with minimal contamination, and is shielded from weather damage.
  4. Pest and Disease Management: Enclosed environments naturally deter pests and diseases, eliminating the need for synthetic pesticides.
  5. Water Efficiency: Greenhouse systems can save up to approximately 95% of water per kilo of cotton by using recycled rainwater for irrigation.
  6. Soil Conservation: Substrate cultivation is soilless and therefore prevents soil erosion, preserving fertility and health without compromising quality.
  7. Localized Production: Greenhouses support local economies and sustainability by minimizing transportation needs and enhancing community resilience.
  8. Prolonged Plant Lifespan: Greenhouse environments enable multi-seasonal plant cultivation, improving sustainability and productivity.
a person with a blue shirt looking at a plant


Did you know that a regular pair of jeans can travel tens of thousands kilometers on its manufacturing journey? We joined forces with local suppliers to create the first locally sourced and manufactured jean – reducing the supply chain distance to just 644 km. Every aspect of cotton processing and production of the garment was completed within the country. From ginning (separating cotton from its seeds) and spinning to weaving, sewing, dyeing and finishing. Along the way, we used electric vehicles between local suppliers, creating the shortest possible supply chain with the least impact.
Cotton and Ginning Wageningen University & Research (Bleiswijk), Dutch Cotton B.V. (Amsterdam)
Cotton & Ginning Wageningen University & Research (Bleiswijk)
two men are working on a machine that is cutting cotton
Cotton & Ginning Dutch Cotton B.V. (Amsterdam)
a close up of a machine that is spinning a thread
Spinning Jenny (Nijverdal)
two people working on a machine in a factory
Weaving Enschede Textielstad (Enschede)
a woman holding up a piece of fabric in a factory
Sewing & Trims G-Star Headquarters (Amsterdam)
a woman in blue overalls hanging clothes on a clothesline
Dyeing Blueprint Amsterdam (Lijnden)
a person is sewing a label onto a pair of jeans
Trims & Labels Van Engelen & Evers B.V. (Heeze)


This is just the beginning of a promising journey towards more sustainable cotton growing. We are currently in phase two of our Homegrown Denim project exploring practical cotton cultivation and scale-up production. In addition to optimizing growing methods, the primary goal this year is to enhance cotton yield per square meter, aiming to increase it from 1.2 kg to 2.2-2.5 kg. After that, future steps would involve inviting other industry stakeholders to join forces, co-invest, and amplify our efforts – generating substantial impact and contributing to reshaping the fashion supply chain for the collective good.


Back to top