How young is TOO young for my students to start blogging?

I believe it is a student by student matter whether they're too young to blog or not. Some students could begin as soon as they learn how to read and write because they just have that want to express themselves. For others, it may take a couple years because they may not have that feeling of wanting to express themselves. As long as a student wants to make a blog and express themselves in that way, I believe it is ok for them to do so. On the other side of that coin, I believe that as long as you still want to express yourself, you can never be too old to blog.