There are only two good times to visit the Japanese Friendship Garden in San Diego’s Balboa Park: When the cherry blossoms are in bloom, or when they aren’t! Right now, there are still a few late season blooms on the trees and the tourists haven’t arrived yet, so it’s a perfect time to grab your camera and go.
Many of the things to photograph are so subtle, it’s hard for me to suggest only one lens. Unless you carry two or three lenses, starting with a macro, this might be the venue for a point-and-shoot bridge camera like the Canon SX series. You’ll want to get there early or late to take advantage of the soft colors and shadows, and avoid the weekends if you can because of the relatively confined spaces.
If a docent is available, take the time to learn more about what you are seeing and photographing. A lot of it may seem overly ‘Zen’, but there were very practical reasons for things such as the koi fish and the shishi-odoshi (scare the deer).