The exhibit is called "Blooms of the British Isles" and will showcase heritage varieties from peonies and stocks, as well as orchids.
The garden will also educate the public on "the importance of seasonal British blooms".
M&S flower expert Simon Richards said: "We are very excited to feature at Chelsea again this year, especially with a theme that is so important to M&S. As a nation we grow some of the world's most beautiful flowers and plants. We want to celebrate these iconic blooms and champion the growers behind them."
The "Blooms of the British Isles" garden will be represented by seasonal flowers from the growing heartlands of Hampshire, Lincolnshire and Norfolk.
M&S did not initially reveal which growers it is using. M&S has previously celebrated Kenyan grown Finlay's flowers at Chelsea in its previous two appearances. Sallis and Chandler are designers of the stand.
Meanwhile, Interflora is also to have a British-grown cut flower exhibit in Chelsea's pavilion.
But NFU/Waitrose's UK Horticulture exhibit will not appear this year.