This is my third Ruth Chew book. They have all been pretty similar: a couple of pleasant but very forgettable kids have some fantastical but very mild adventures.
I read this book last night and have already forgotten the names of the two kids: something common and Anglophone like Susie and Paul. While engaged in the forbidden naughtiness of roasting hotdogs over a fire, they go to get more wood from the garden of the empty house next door, which turns out not to be empty. They have a new neighbor. No spoiler: she's a witch. The plants have magical properties. Adventures Short mishaps ensue.
It's actually rather impressive how not-scary Chew manages to make scenes like being shrunk and chased by giant insects and animals. The kids seem a lot more worried about the girl's parents getting mad that they accidentally threw out the paper before Father was done with the crossword. Maybe that's realistic.
I recommend this for timid kids who don't like suspense, or for bedtime reading. In addition to not being scary, there isn't much plot (incidents happen, but there's no serious danger or ultimate problem to solve) so it won't keep anyone awake.