Make sure to book in advance! They are super popular in the summer time. We did this for our honeymoon and it was lovely. Did the private boat tour so it was just the two of us. A lot more expensive but we thought it was worth it because it was a longer trip and they take you farther down the river. When we were in Venice we choose not to do the gondola because it was very expensive. This place isn't cheap either but we thought it was a wonderful experience boating through the gardens. They are very informative as well and tell you all about the history of the gardens.