Hi Lynne
Have you thought of joining the Royal Horticultural Society (RHS)?
The cost is £44 for the year and gives free entry to many gardens and events such as Chelsea Flower Show. They offer a Plantfinder service which could be helpful to you with selling your herbs and incredible amounts of advice on the identification and culture of planats.
They could probably put you in touch with an expert in your area.

Colyn (whose parents were florists and whose grandfather is perpetuated in the RHS archives due to his production of show auriculas).