The rose garden lies within the confined walls of President Snow's mansion. It served no purpose in the games, but it was where he and Seneca Crane consulted with each other to discuss the events that were to take place within each Hunger Games, such as new tactics, ideas and above all, the competition and talent with each year's fresh batch of tributes.
The rose garden appeared in a short scene where President Snow and Seneca Crane were discussing the games whilst the President was tending to his roses. The garden also appeared during Mockingjay where Katniss Everdeen confronted him whilst he was chained to a chair in the centre of the garden. Even after the Capitol was defeated, he continued to manipulate and control Katniss, especially with the scent of his enhanced roses.
President Snow could be seen often wearing an elegant rose on his suit. The scent is described to be sweet and incredibly overpowering, and this scent had a huge effect on Katniss. Katniss was often found complaining that she continued to smell the lingering scent of the roses that Snow wore, especially where he left a rose on the dresser at Katniss's home in the Victors' Village. She mentions the scent during the meeting in Catching Fire before the announcement of the Quarter Quell, where Snow threatened Katniss that he was not convinced that the star-crossed lovers scheme with Peeta Mellark was real. Katniss thought she could feel the presence of the President everywhere she went with the haunting scent of his roses being the main reason.