I am looking for a children’s book, published in the 1970s or earlier (I was born in 1975, read this sometime between the ages of 7 and 12, and recall the book itself physically feeling “old” at the time). Most probably published in the 50s or 60s.

Two children were the main characters, I think they were a girl and a boy. I don’t remember any names of characters, unfortunately. They lived next door to a witch whose property included a walled and gated yard. When the witch did magic, her hair “floated above her shoulders” or something like that. I remember that rowan trees figured heavily in the story line; either they were searching for them or there was something about them the witch needed.

At the beginning of the adventure part of the story line, the children’s beds turned into boats and they were magically transported to a river or creek while they were asleep – one of the children wakes up because they become aware that their hand or the bed linens are trailing in the water.

I loved this book – hope someone can help me find it.

Thanks!