This just in: A student has just informed me that his trip to the Chicago Botanic Garden’s Heritage and Bulb Gardens found the waterlilies to be in full bloom. He added that there is quite a selection of them to photograph. My advice would be to bring a tripod, use a low ISO setting and begin with every photographer’s best friend f8. Use exposure compensation to hold down the light in one-third stop increments unless the lily is bright white. Keep the light level up for these lilies.
Get to the garden early for reduced heat and visitor levels. Remember to fill the frame to reduce/eliminate those BMD (boring middle distance) shots.