For bonus points, use this technique to avoid jaggies on your foliage (not invented by Wolfire, but they have a relatively short clear explanation): http://blog.wolfire.com/2009/02/rendering-plants-with-smooth-edges/
TLDR version: Render all foliage twice. First pass use clip/discard/alpha test on your foliage (as Hodgman describes). Second pass, render with alpha blending.
A more correct solution might be to look into alpha-to-coverage with multi-sample antialiasing.