Drizzle by Kathleen Van Cleve

Eleven year old Polly Peabody lives on a magical rhubarb farm.  It grows chocolate rhubarb and giant rhubarb and it rains there every day at 1 pm.  Then, when her aunt wants to sell the farm, the rain stops, her rhubarb friend stops talking to her and her brother gets deathly ill.  Only Polly can save the farm, but she does not kow how and she is too afraid to do many things.  Throughout this magical adventure, Polly learns to conquer her fears as she finds out the secrets that her farm is hiding and how she alone can help to save it.  This is a fun and uplifting fantasy for kids.