How many books are in the The Witness Tree series?

There are 4 books in the The Witness Tree series.

When will the next book in the The Witness Tree series be released?

The The Witness Tree series does not have a new book coming out soon. The latest book, White Wind (Book 4), was published in March 2011.

The first book in the The Witness Tree series, The Legend of Summer Swan, was published in June 2009.