The 16,000 sq ft Covent Garden site will feature two restaurants, a lifestyle home and garden shop and a delicatessen with a wine cellar and florist.
Petersham Nurseries Covent Garden Potting Bench shop, delicatessen, florist and wine cellar opens in June. The two restaurants, the Petersham and La Goccia, open in September.
Daughter of Petersham's founders Lara Boglione will be managing director.
The kitchens will be headed by executive chef Simon Whitley.
Architects are Michaelis Boyd.
Chef Skye Gyngell made Petersham the best known garden centre industry's restaurant between 2004-12.
Meanwhile, Trotton Garden Centre in Hampshire has re-opened. It was sold in 2015 to Eco Warrior Resorts who changed the name and tried to redevelop the site. The new owners bought the company from liquidators. Commercial director is Michele Gaudelli.