Here's a blog posting with lots of pictures of a coffee growing area in Pingtung County. Dawu Village is near the trail head that one can take to climb North Dawu Mountain. Apparently it's possible to hike to Taitung County on this trail.

http://blog.xuite.net/seahong/red1/45657118

You can Google 大武村咖啡 for more results. Coffee is growing everywhere in this area, and although it was obviously cultivated, there appeared to be many untended trees that were doing just fine, full of beans.