My wife and I have each been going to the garden since we were little kids. Today we live nearby and go once a week on average. It is an amazing place and one of my favorite attractions to bring Saint Louis visitors to. The Japanese garden (Seiwa-En) and English Woodland gardens are my personal favorites and I have volunteered in maintenance of the Japanese garden which is one the largest Japanese style garden in North America. So go there, feed the fish, buy a cactus, relax, see a rain forest, take your kids to the hedge maze, and learn something new. Peter Wyse Jackson, the current President of the Garden is a great new addition as well!
The Missouri Botanical Gardens is one of my favorite places to visit. The beautiful Japanese Garden, the English Woodland Garden, and the Tropical Climatron are just the beginning of the wonders available for exploration. In additon, there are the Japanese Festival, a tremendous weekend-long celebration, the Chinese Culture Days, the Orchid Show, the Holiday Train show, the Children's Garden and other special annual events that add so much value to the Gardens.
As one of the largest Botanical Gardens in the World, MoBot is a true treasure that deserves more recognition. They are actively involved in research and conservation worldwide as well. If you have never seen it, make sure it is on your itenerary when you come to Saint Louis.