The obvious answer is that you have to create content that has value for educators. Think about the problems they have, the questions they need answers to, and write blog posts that address these concerns and answer their questions.

The second thing you should do to grow your readership is to make a list of the top 3-5 sites where educators are going today to get their information, and start commenting on those sites. As you leave smart and relevant comments on these sites that educators are reading, it will increase the chances of them checking out YOUR blog.

Do both of these together, and you will see your readership grow pretty quickly.