In 1928, William Bradley began a mail order seed company called Dominion Seed House, which was located on the edge of Georgetown, Ontario, on a portion of the family farm. Eventually it became the largest and most successful catalogue seed distributor in Canada. Its distinctive mock-Tudor building was featured in all of its catalogues and became emblematic to gardeners across the country as a source of top quality seeds. Mr. Bradley traveled the world in search of new plant varieties, which he then offered to delighted Canadians and gardeners around the globe.

The Dominion Seed House business remained in the Bradley family until 1993, when it was sold to a Quebec firm and the property in Georgetown was put up for sale. While the property was left fallow, it was evident that an abundance of perennials were still alive and well in the fields.

The Georgetown Chapter of the Canadian Federation of University Women, seeing both the waste and the potential, organized a "Dig Your Own Plant" sale in May 1996. This rescue mission struck a chord with gardeners across Ontario, who drove from as far away as Sarnia and North Bay, to preserve this valuable heritage plant material. The club dedicated the profits to the establishment of a civic garden on the site of the Dominion Seed House, and began lobbying the Town of Halton Hills to endorse this concept. After extensive public consultation, Halton Hills Council approved a master plan for an 8 acre park which included a 2 acre civic garden: The Old Seed House Garden.

It was understood throughout the process that the Garden was to be largely a volunteer driven project. A Steering committee of volunteers was formed in 1999 and on January 20, 2000, The Friends of the Old Seed House Garden was officially launched. Memberships were sold and committees formed to tackle each of the many challenges ahead.

Membership in The Friends of the Old Seed House Garden is open to anyone. It is a registered charitable organization with a constitution, and Executive Committee, and its own logo. The Friends work in partnership with the Town of Halton Hills, which is developing the remainder of the park.