Gartenkultur of Italy drilled holes in hardback books, puts in some mesh, and paints the pages with an insulating layer so that the pages won't get wet, fills up the hole with soil and plops in a plant. It's a bit meta, since, of course, books are made from trees, and now trees are growing inside the books!
Some books that have been drilled, but not yet filled with soil and plants.
Clearly, Gartenkultur has put some thought into choosing the books to transform into planters, whether it's because of the title or the placement of the planter hole, much like this edition of Shakespeare, which has a small hole drilled to match the portrait of Shakespeare on the cover.
Some of the plantings are more exuberant, like this telephone directory that has a miniature tree sprouting from it.
Or this lavishly illustrated cover, with a patchy of alien-like stumpy succulents replacing the face's hair.
Gardenkultur doesn't seem to make their growing books any more, but you can check out their gallery of past projects.
[via If it's hip, it's here.]