Quality of            
Growing Media 

RHP has been the European knowledge centre for growing media since 1963 

RHP certified substrates provide an optimal start of the culture. With the RHP quality mark you increase the security that the substrate complies with the quality requirements concerning for instance water uptake, air content, pH, EC and nutrients. It also offers more security that the substrate is clean and that it can be used without risks for the culture. The RHP quality mark monitors the quality of growing media in the chain, from raw materials production until processing and delivery at the company of the user.


RHP Certified for Horticulture coir products, peat, growing media (to: all certified products)


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  • March 11 - meeting Supervisory Board
  • March 21 - meeting Product Group Coir
  • March 21 - meeting Product Group Mineral wool
  • March 26 - meeting Steering Group Research
  • March 27 - meeting Product Group Compost
  • March 27 - meeting Product Group RAG Landscaping
  • March 28 - RHP Online Research Update (webinar for certified companies)
  • April 4 - Technical meeting for RHP members in the Baltics & Nordic
  • April 11 - Knowledge Day Substrate
  • April 12 - meeting Product Group Peat
  • April 18 - meeting Product Group Mineral products
  • April 24  - Harmonization day for auditors of the RHP and RAG quality marks
  • April 25 - meeting Product Group Fertilizers and lime
  • May 15 - meeting Product Group Organic products
  • May 17 - meeting Product Group Endproducts Horticulture
  • June 14 - meeting Central Board of Experts
  • June 24 - meeting Supervisory Board
  • September 23 - meeting Supervisory Board
  • November 5 - meeting Product Group Mushrooms
  • December 12 - meeting Supervisory Board

Facts & Figures

The knowledge center for substrates in Europe

Quality 100%
PRODUCT analyses 14.592
9999K m³

Knowledge Base

The ins and outs of substrates: from WOK to respiration and from potting reference to pH

certified products

Raw materials and end products classified per field of application

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