Hardly any seedbank has shaped the image of cannabis in the 21st century as much as Green House Seed Co. Founded in Amsterdam in 1985 by Arjan Roskam, the company has won more than 35 High Times Cannabis Cups. Behind this success lies a story shaped as much by marketing genius as by ethical debate.

1. The rise of the “King of Cannabis”

Arjan Roskam realised early on that a seedbank's success also depends on its brand. He styled himself the “King of Cannabis”, and his coffeeshops became a meeting place for international stars. But behind the glamour there was real substance: in the 1990s Green House created strains that changed the cannabis world – above all the legendary White Widow and the sativa masterpiece Super Silver Haze, both multiple cup winners.

2. The Strain Hunters era

Together with his charismatic head breeder Franco Loja, Arjan founded the Strain Hunters. Their mission: travel to remote regions of the world to find and secure endangered landraces – the original genetics of the plant. The expeditions were captured in documentaries that inspired millions.

Franco Loja became the heart of the brand. His death in January 2015 – he contracted malaria during an expedition in the Congo – shook the community worldwide. The strain Franco's Lemon Cheese was created in his honour.

3. The dark side – criticism of their approach

As great as the enthusiasm for the films was, the criticism from experts was just as clear. The Strain Hunters' approach was often perceived as neo-colonial: the local farmers who had preserved these genetics for generations often appeared as mere extras. Fair benefit-sharing with local communities was hardly visible.

4. The genetic paradox

The most serious accusation concerns botanical ethics. The videos showed modern hybrid seeds from Europe being handed out to local farmers as gifts.

• Genetic dilution: when Western hybrids reach regions with stable landraces, the original varieties can be irreversibly altered through cross-pollination – meaning the “rescuers” may have contributed to the loss of those landraces.
• Few visible results: the Green House catalogue contains hardly any pure landraces. Critics therefore see the expeditions mainly as a marketing tool, while the seeds sold remained mostly modern crosses.

Conclusion – marketing empire or conservation?

Green House remains an empire that brought cannabis out of the shadows and inspired generations of growers. Arjan Roskam is seen as the visionary, Franco Loja as the unforgettable soul of the brand. Yet the Strain Hunters story also shows the tension between the commercial hunt for the next hype and the quiet, genuine work of preserving genetic diversity.