The pursuit of information on Japanese green tea remains pretty difficult. There are few good books in english…the most informative are of course written in Japanese. That said, Japanese print (especially magazines) are almost unbelievably thorough. If you get one good zine on tea and a Japanese friend to help you, you can start growing and manufacturing your own stuff. Seriously. Ever wondered what nitrogen levels are best for growing tsuyuhikari? Maybe you didn’t. Well, I did. And the answer was in Discover Japan’s tea issue!
Here are a few links to some informative reference material. have fun, and if you can’t read anything, the pictures are really nice, too!
Discover Japan 茶
日本茶 (Japanese Tea)
Characteristics of 8 Japanese tea cultivars
Tea Enthusiast’s Handbook