Introducing OHAS

The Ornamental Horticulture Assurance Scheme (OHAS) is a specialist grower group of the HTA. Formed over 21 years ago, it aims to raise the standards in ornamental horticulture in the UK.

Scheme certification

The scheme certificates growers, packers and growing media manufacturers to the OHAS Standards, through unbiased independent inspections carried out by a UKAS accredited certification body (NSF Certification Ltd). The inspections form the basis of the scheme to set the highest standards of professionalism in the way our members operate.


All members of the OHAS scheme receive an annual inspection, which provides customers with complete confidence in both product and service. The inspections also provide our members with the confidence that their business is up to date with the latest legislation and best practice.

Benefits of belonging to OHAS

Benefits of being a member of the scheme include:

  • Meet customer requirements.

  • A method to manage and continuously improve your business.

  • Ensure you are legally compliant.

  • Reduce your impact on the environment and manage resources sustainably.

  • Full traceability for all your products.

  • A framework to manage staff and develop skills.

  • Membership of a recognised industry body.

  • Support to gain certification.

Through this site, you will be able to find all relevant information to help your business grow, but also information around events, and background on the committee and key staff members who are dedicated to working for you. With the full support of the HTA, the Committee is keen to develop the OHAS Scheme and continue to promote the achievements of our members.

OHAS Members

A list of OHAS members can be downloaded here.

OHAS & PHCS: Alignment FAQs

Download FAQs