I'm just wondering though, is early March too early to see the cherry blossoms?Yes, it is too early. They do not start bloom until around late March.
Small numbers of early blooming cherry tree varieties can be seen in some parks, though, e.g. Shinjuku Gyoen. It is just a few trees, but can also be enjoyable. Nothing like the actual season that starts in late March, though.
More information:
http://www.japan-guide.com/e/e2011.html