Managing director Ross Allan has had three detailed planning applications along with drawings and landscaping plans submitted to Scottish Borders Council last week.
The applications include planning permission for 40 homes, an expansion of Milestone Garden and Leisure to include, increased restaurant space, a new coffee lounge, fitness gym and larger garden and gift departments.
The plans also include some serviced business units on the site as well as a separate residential property.
Since Milestone opened in September 2006 it has had more than three million visitors, and put in more than £4 million pounds into the local economy, through the employment of local people. The garden centre has also sold more than 2.5 million trees, shrubs and bedding plants.
Allan said: "Milestone Garden and Leisure is proud to be based in the Scottish Borders and is very much part of the Newtown St. Boswells community. The planned development will bring increased footfall and business opportunities to this part of the Scottish Borders.
"During the past eight years we have helped many local young people to get on the career ladder, provided employment experience and career opportunities for local people and have worked with community groups and charities to enhance Scottish Borders living."
"The next phase will be really exciting not only for the Milestone team but also the local community and the Scottish Borders as a whole."
Camerons Architects director Mike Davidson said: "Having been involved from the original creation of Milestone 8 years ago and seeing the great success of the business, it is exciting for Camerons Architects to be involved in the next phase of the development."