Looking for a little garden inspiration? This spring, think up rather than down. This vertical garden, located on the exterior walls of the shopping mall Fiordaliso Rozzano near Milan, is currently the world's largest, boasting 44,000 plants. While most of us don't have that kind of time or space to dedicate to our flora (this installation took three months to complete), you can start plotting your own upright bed of flowers, indoors or out, with a couple quick tips from our friends at Gardenista.