Most people don’t pay any attention to grass and the way it grows, but British artists Heather Ackroyd and Dan Harvey have always been fascinated by it and have found an ingenious way to incorporate it into their art. By manipulating the way grass grows, they are able to literally print detailed photographs onto a living wall of grass that develops according to how much light it receives.

The two artists start by covering a large canvas with water paste and rubbing germinated seeds all over it. They then cover the windows of their studio turning into a dark room, and making sure that the only light that reaches the canvas is projected through a slide of a negative photograph. They then let photosynthesis run its course, and in a few weeks time the grass-covered canvas grows into a living print of the photograph. The amount of light shining through different parts of the negative determines which parts of the canvas turn out a vibrant green, and which remain yellow and undeveloped, making the details of the image clearly visible from a distance.

For the past decade Ackroyd and Harvey have been manipulating the light-sensitive chlorophyll in the blades of grass to create different shades of green and emphasize the details of the projected negative image on the canvas. “Where the strongest light hits the grass it produces more of the chlorophyll, more of the green pigment, where there’s less light, it’s less green, and where there’s no light, it grows, but it’s etiolated and yellow,” Dan Harvey told Great Big Story. ” So you get the equivalent of a black and white photograph, but in tones of green and yellow.”

If watered regularly and kept in low light conditions, these living works of art can last indefinitely, but just like vintage photographs, they fade from their crisp and green hues over time.

We first featured the incredible grass art of Heather Ackroyd and Dan Harvey in 2012.

Photos: Heather Ackroyd & Dan Harvey