I read this book in my teens, and was charmed. I've been looking for a copy for my teen daughters for a number of years.
Despite being written in 1966, this book has strong women, (actually girls) and a very funny, and interesting story line. 32 years later, I was charmed and delighted by the book- it was better than I remembered!
Essentially, it's space opera, with witches, and worms, and a lot of very funny situations.