The idea of a National Botanic Garden of Wales at Middleton Hall originated with William Wilkins of Carreg Cennen, Trapp.  With a great deal of enthusiasm and effort he succeeded in getting the idea implemented, before leaving to restore Aberglasney, a garden a few miles away on the north bank of the Towy.

He first heard about the Middleton Hall estate from his aunt, who had returned from a Dyfed Wildlife Trust walk at Pont Felin Gat soon after the Manpower Services Commission had re-built the cascades and improving the pathways.  She told her nephew about the archaeological remains she had seen.

William Wilkins visited Middleton and on exploring the estate was impressed by the quality of the surviving ruins and their high aesthetic standards.  He realised that this was part of a garden heritage that was neglected and much more important than many people had realised.  It was at this point that he began to think of practical ways of getting a high quality restoration programme underway.  He saw that the end product must have a role in contemporary life ensuring on-going viability, and justifying the expense of restoration.  With this in mind, he and some friends planned to set up a Trust to be called the Towy Valley Gardens Trust.  However, after much discussion William Wilkins was persuaded that it should not only be a Trust for the Towy Valley, but for Wales as a whole; and thus the Welsh Historic Gardens Trust (WHGT) was founded.

It soon became apparent to William Wilkins and his friends that very few people knew of Wales’ rich garden heritage.  He set out to get the support of the ‘great and the good’ in order to prove to the Welsh authorities that Welsh gardens were valued and respected outside the Principality.  One such supporter was Ghillean Prance, Director of the Royal Botanic Garden at Kew who was asked to join the Trust’s council. A meeting was then called by Edmund de Rothschild to discuss the feasibility of the idea and to consider a number of potential sites.

Having persuaded Ghillean Prance and Edmund de Rothschild that the site at Middleton Hall was worth looking at, they visited the estate and Dyfed County Council became interested in their plan.  Following these meetings the WHGT began to seriously consider the estate in terms of a botanic garden development. A working group was set up under the chairmanship of Dr Andrew Sclater. This in turn became part of a steering group chaired by David Bown, County Planning Officer of Dyfed County Council.  The Welsh Development Agency, Countryside Council of Wales and Wales Tourist Board were represented along with the County Council and members of the WHGT working group.  The steering group produced a pre-feasibility study. This led to a full feasibility study by the group on the viability of a national botanic garden for Wales.

At this point William Wilkins was asked to become Project Director and commissioned to take the scheme forward.  He began to seek the approval of the Welsh Office for the title ‘National’.  He made presentations to two successive Secretaries of State and Permanent Secretaries, starting with David Hunt.  At last a study was commissioned by the Welsh Office to look at all possible sites in Wales, the results of which left Middleton free to make an application to the Millennium Commission.

The formation of the Millennium Commission meant that what William Wilkins had envisaged as a twenty-year project could now be completed in half that time.  He set up a charitable company to raise funds for the project and to develop the concept and design.  A Board of Trustees was recruited and over a period of approximately two years the steering group handed over the management of the Garden to the Trustees.

The application for support from the Millennium Commission was submitted on the first day of the organisation’s existence, and was formally announced on March 1st 1996.  Brian Thomas was elected the first Chairman of the Trustees. In September 1996 the Trustees appointed Charles Stirton as the first Director of the Garden.  In 1997 Brian Thomas stood down as Chairman, and has since been succeeded by Dan Clayton-Jones, Alan Hayward, Robin Lewis, and from 2009, Rob Joliffe.