17 february 2026
In 2026, RHP knowledge center for substrates proudly celebrates its 40th anniversary as a foundation.
Our activities go back much further. At the research stations in Naaldwijk (in Westland, the heart of Dutch horticulture) and Aalsmeer, the first steps were taken to improve the quality of potting soil. In 1963, this resulted in a unique national collaboration between research institutes, governmental advisory services and companies involved in raw material extraction and the production of potting soil. This collaboration laid the foundation for what we now know as RHP. When the government stepped back in 1986, the collaboration was privatised and RHP became the independent, non-profit foundation it still is today — built on decades of research, practical knowledge and cooperation across the sector.
While the early focus was mainly on peat-based raw materials for potting soil, our work has evolved alongside the sector. Today, we research and assess a wide diversity of (renewable) raw materials and growing media. We develop unique expertise and actively share this knowledge throughout the supply chain. More and more types of raw materials are covered by our quality marks, which continue to expand and evolve with sector developments.
What started in the Netherlands has grown into a global network. All over the world — from the United States to Asia — certified companies are connected to RHP. Companies that dedicate themselves every day to ensuring the quality of raw materials and growing media. Together, we build safe, high-quality and future-proof growing media, wherever they are produced or used.
In this anniversary year, we look back on more than 60 years of knowledge development and more specifically on 40 years as the RHP foundation — and we also look ahead. Together with the sector, we continue to work on quality, safety and responsible production of raw materials an growing media.
