Garden Park Investments (GPI) is behind the 9,000sq m of retail space set in parkland, which is due to open this year.
Van Hage has a 25-year lease on a 5,000sq m centre with an 8,000sq m external sales area.
The Peterborough site also features 17 retail units.
Hammond Phillips and Cushman & Wakefield are joint letting agents for the scheme.
Six lettings are to be announced before Christmas.
GPI announced a £50 million investment fund aimed at building a portfolio of garden centres in September.
Early negotiations are understood to be underway with a number of garden centres.
GPI is due to submit designs for a further site in Hampshire to planners this December.
GPI CEO Edward Olley said: "With centres finding it difficult to raise finance for new property investment, it's an attractive way to raise finance."