i went there on a Sat morning. they didnot have guided tour every sat , so i did a self-guided tour. it was a very good one. for 15$ they give you a very comprehensive information handbook with each of the plant and spot of the garden on it. if you read through everyone, it will probably take 2 hours. i was on a schedule, so i did it in an hour, felt a little rushed. the view is great. the valley is beautiful, and you learn a lot. they do have guided tours every weekday.