Last verified: April 2026

Sensi Seeds & Ben Dronkers: The Foundation

Ben Dronkers founded Sensi Seeds in the mid-1980s, making it one of the oldest commercial cannabis seed banks in the world. Operating openly from Amsterdam during a period when most of the world treated cannabis seeds as contraband, Dronkers built a catalog of genetics that would become the foundation of modern cannabis breeding.

Key Sensi Seeds contributions:

• Northern Lights — Originally bred in the Pacific Northwest and refined in the Netherlands, Northern Lights became one of the most influential indica strains in history. Nearly every modern indica hybrid traces ancestry to Northern Lights genetics
• Skunk #1 — The original hybrid that bridged indica and sativa genetics. Won the first Cannabis Cup in 1988. Skunk #1 is a parent strain in hundreds of modern cultivars
• Jack Herer — Released in 1994 and named after the American cannabis activist and author of The Emperor Wears No Clothes. A sativa-dominant hybrid that won multiple Cannabis Cup awards and remains a benchmark strain decades later

Dronkers also founded the Hash Marihuana & Hemp Museum on Oudezijds Achterburgwal, housing over 12,000 objects related to cannabis history. His legacy is not just genetic — it is cultural.

Dutch Passion & Feminized Seeds: The Revolution

Henk van Dalen founded Dutch Passion in 1987, and the company’s single greatest contribution to cannabis history was the invention of feminized seeds. Before feminization, roughly half of all cannabis seeds produced male plants — which are useless for flower production and must be identified and removed before they pollinate females.

Feminized seeds produce female plants with near-100% reliability. This innovation:

• Eliminated the need to sex plants, saving growers weeks of labor
• Made home growing accessible to beginners worldwide
• Reduced waste (no more discarding half your seedlings)
• Became the industry standard — today, the vast majority of commercial cannabis seeds sold globally are feminized

Dutch Passion continues to operate from Amsterdam and remains one of the most respected seed banks in the world.

Greenhouse Seeds, Arjan Roskam & Shantibaba: The Cup Dynasty

No discussion of Amsterdam genetics is complete without the Greenhouse Seeds story — and the collaboration that produced some of the most famous strains ever created.

Arjan Roskam, the self-proclaimed “King of Cannabis,” founded Greenhouse Coffeeshop and its seed division. But the strains that built Greenhouse’s legendary reputation were created in partnership with Shantibaba (Scott Blakey), an Australian-born breeder:

• White Widow — A Brazilian sativa crossed with a South Indian indica. Released in the mid-1990s, White Widow became the most famous Dutch coffeeshop strain and a staple on menus worldwide. Frosty, potent, balanced
• Super Silver Haze — Won three consecutive Cannabis Cups (1997, 1998, 1999). A Skunk, Northern Lights, and Haze cross that set the standard for sativa-dominant hybrids

In 1998, Shantibaba left Greenhouse to co-found Mr. Nice Seeds with Nevil Schoenmakers (the pioneer of seed banking) and Howard Marks (the infamous Welsh cannabis smuggler). The split was acrimonious, and both parties claimed credit for strains they had created together. The dispute remains one of Amsterdam’s most well-known cannabis industry feuds.

Strain Hunters & Franco Loja

Greenhouse Seeds gained a second wave of fame through the Strain Hunters documentary series, which followed Arjan and breeder Franco Loja as they traveled the world collecting landrace cannabis genetics from remote regions of Colombia, India, Malawi, and elsewhere.

The project ended in tragedy. On January 2, 2017, Franco Loja died of cerebral malaria contracted during a Strain Hunters expedition in the Democratic Republic of the Congo. He was 42. Franco was widely respected in the Amsterdam cannabis community as a passionate, knowledgeable breeder, and his death was felt far beyond the industry.

Barney’s Farm: Himalayan Connections

Derry Brett founded Barney’s Farm with genetics sourced from expeditions to the Himalayas, Nepal, and Southeast Asia. Operating from the famous Barney’s Coffeeshop in Amsterdam’s Centrum, the company has won more Cannabis Cup awards than nearly any other seed bank.

Notable strains:

• G13 Haze — A legendary cross involving the mythical G13 genetics
• Tangerine Dream — A fruity, balanced hybrid that won the 2010 Cannabis Cup
• Liberty Haze — Cannabis Cup winner known for its lime-scented, energetic effects

Royal Queen Seeds & the Future

Royal Queen Seeds, founded in 2007, represents the modern generation of Amsterdam genetics. While building on the classical Dutch breeding tradition, they became the first company to release F1 hybrid cannabis seeds in 2023 — a technique borrowed from agricultural science that produces more uniform, vigorous plants with predictable characteristics.

The Amsterdam Genetics / Boerejongens operation, led by Mariska, has taken a different approach — focusing on quality-controlled house strains sold exclusively through their own coffeeshop locations. This vertically integrated model (breeding, growing, retailing) may represent the future of the Dutch cannabis industry as the Closed Chain Experiment moves toward regulated supply.

Cannabis genetics research

The Netherlands remains one of the few countries where cannabis seed production and sales are legal. Seeds contain no THC and are treated as agricultural products under Dutch law.