Some call him The King of Cannabis, but Arjan Roskam doesn’t care much for titles—or expectations. “I have one philosophy in life,” he told us at Spannabis Barcelona 2025 with a half-smirk and a shrug. “I don’t really give a fuck, to be honest. Whatever happens, it’s fine. I don’t really care.”
That devil-may-care attitude has taken him from youth rehab clinics in Thailand to the summit of global cannabis breeding, where his brand Green House Seed Co. reigns as one of the most awarded and recognized names in the world. But behind the bravado is a story rooted in destiny, dirt, and seeds that were always meant to grow.
The Monk and the Seeds
Long before Amsterdam’s coffee shops became tourist staples, Roskam was just a 17-year-old kid traveling solo through Asia. Looking for a place to sleep one night in Thailand, he stumbled upon an unexpected haven: a rehabilitation center run by a 78-year-old man using traditional healing methods—including plant medicine.
“He was helping people puking and shit,” Roskam recalls bluntly. “I stayed there seven days. At the end, he gave me a bunch of seeds and said, ‘Take these back and start growing them.’”
The man wasn’t just handing over genetics—he was passing on a mission.
“He took my hand, put the seeds in it and said, ‘These seeds are going to overthrow governments.’”
That moment—part spiritual transfer, part prophetic vision—planted more than just plants. It marked the beginning of a decades-long legacy that would influence genetics, activism, and global agriculture.
Green House Rises in Amsterdam
In 1992, Roskam opened the first Green House Coffee Shop in Amsterdam. The timing was critical. While Amsterdam was already becoming synonymous with consumption, the market was still young and rough.
“There was no weed,” he says. “95% was hash—from Morocco, Nepal. Only 5% was what we called ‘Nigerian’ or ‘Jamaican swag,’ those brick-pressed blocks full of seeds.”
From that gritty landscape, Roskam and Green House began to elevate the standard. By chasing landrace strains—ancient varieties native to regions like Colombia, India, and Thailand—he preserved vital plant knowledge that would shape modern breeding.
“Landraces are varieties that have grown 40, 60, 80, even 200 years in a specific area. Colombia was amazing. A lot of what’s grown there now is from our seeds.”
Beyond business, Green House became a vehicle for social change. Through their Strain Hunters project, Roskam and his team traveled to remote corners of the world, documenting and protecting endangered genetics, empowering farmers to grow something better, and exploring the roots of cannabis culture on a human level.
“We wanted to convert some farmers from doing one crop to another—with our crop. And that went great.”
On Legalization and the Global Mess
Despite his global success and industry veteran status, Roskam doesn’t pull punches when it comes to current legalization models.
“Not a single country has done it right,” he says. “Stupid rules, politics, listed companies, a million issues.”
He’s especially critical of markets like the U.S. and Canada, where red tape and commercialization have stifled creativity and access.
“America? Really? What the hell. Canada? Overregulated, overtaxed.”
But Roskam believes the future of the industry is inevitable—and it's going to look a lot like wine.
“You’ll have big brands making supermarket weed. Then you’ll have craft guys like us with specialty lines. And then small growers—like winemakers with a few hectares—producing amazing flower.”
In other words, mass production may coexist with artisanal excellence, and there’s room for legacy to live alongside innovation—if the industry chooses to respect it.
The Herb That Heals the Brain
Even with a legacy cemented in trophies, trophies aren’t the point for Roskam. It’s always been about something deeper. The seeds he received as a teenager came with a calling, not just a crop.
“Cannabis is the most important herb on this planet for the healing process of the brain.”
He’s still chasing that healing—whether through genetics, education, or advocacy. For Roskam, the plant is both weapon and remedy: A tool to shake power structures and a medicine to soothe human pain.
And that’s why, after all these years, he’s still here. Still growing. Still showing up. Still holding seeds in his palm—ready to pass them on.
For more, visit https://shop.greenhouseseeds.nl; Instagram; Arjan Instagram; Strain Hunters
