The Green Wall of Van Gogh is the perfect example of vertical gardens.

Planted in London's Trafalgar Square, the vertical wall is the first of its kind to emulate a classical painting. The Green Wall of Van Gogh interprets Van Gogh's infamous 'A Wheatfield with Cypresses' piece.

Using over 25 different types of plants, the wall is composed of about 8,000 plants. Before installation, the plants were grown in modules that were hung vertically. It took about three days to install the wall, with the piece designed to flower as the season progresses. The wall was commissioned by the National Art Gallery and General Electric (or GE) as a way to draw audiences to see the original painting. The wall has also become a symbol of the National Gallery's initiative to become more eco-friendly.