We might have to make another small adjustment to the kindergarten Christmas party schedule.
If 幼稚 is childish, then a garden for childish people would be a place full of lots of children, probably growing in some way. When you're growing little children in a garden, you're putting them into some kind of school. In this case, it's a kindergarten.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well. Will help to know 幼稚 as well.