The original greenhouse was on the corner of 18th and Grand until 1912, when it was relocated to its current location. It was renovated in 1974 in anticipation of the World Expo, and the central dome was added in 1988. The greenhouse served many purposes in the early days of the park with its most important function growing seedlings and storing plants and tools for the park. During the long Spokane winters the greenhouse was heated with coal.
Once the City of Spokane acquired Manito Park in 1904, everyone wanted to give his or her opinion on what should be planted and how the park should look. A letter was given to the acting park board suggesting a reward be given to the landscaper who came up with the most reasonable plan for the land at Manito. Though this never happened, it did prompt the hiring of the Olmsted brothers, world famous landscape architects, who contrary to popular belief did not design the park, but just gave recommendations.
Prior to 1974 the greenhouse was off limits to visitors of the park except during special occasions like Christmas and Easter. During the 1974 World Expo people were allowed inside the greenhouse for the first time to view special floral displays. Currently the Conservatory acts as both a small indoor botanical garden and as a greenhouse for the park. Visitors may enjoy the conservatory during all seasons with a rotating display of succulents, desert plants, orchids, and flowers.