Yes, as a reader guessed, this is the Warder Nursery, located in Finneytown, but owned by the City. I did find some info:
A 1998 Cincinnati Enquirer Article says:
Warder Nursery will be developed into a park, with both recreational and green space, after the Cincinnati Park Board agreed Thursday to sell or lease the area to the township.Proposed
The park board passed a resolution at its meeting that allows the township, where Warder is located, to either buy it outright or lease it for 10 years.
The primary stipulation is that the area not be developed into something other than a park. The township has said it would develop the 42 acres into both playing fields and green space, possibly with hiking trails.
The trustees were pleased with the outcome of deliberations that began more than a year ago, as were township residents who had been behind a grass-roots effort to preserve the area more than two years ago.
...Warder Nursery is in the southern part of the township, just north of the Cincinnati city limits. The 49.6 acres have long belonged to Cincinnati and in recent years, the park board has maintained greenhouses on the property, where they propagate plants for Krohn Conservatory and floral displays throughout the city.
Under the agreement, Cincinnati will keep and maintain the greenhouses and about 10 acres of the property.
Since most of the acreage is unused, the park board had been approached in recent years by housing developers expressing an interest in buying the property.
That prompted the civic association and township residents to explore ways of purchasing the property and keeping it out of developers' hands.
The trustees have said they will soon decide whether to buy the property outright for about $720,000 or lease it over 10 years for about $920,000.
Design for Warder Park
Here is the site on Google Maps
View Larger Map