Guerillas in the Rough: Guerilla Gardening in the Core of One of the World's Largest Cities

Guerilla gardeners make sure to introduce flora that will grow and thrive in local conditions. Here a group of British gardeners take on a rough patch of land on a traffic island in a busy section of London.

Many guerilla gardeners consider their work "proactive activism" aimed at making tangible positive changes in their communities.

While this bed of tulips was planted by industrious guerilla gardeners, some guerillas prefer to use seed bombs. Seed bombs, or green grenades, are mechanisms designed to help disseminate seeds without detection.

Guerilla gardeners consider the climate and conditions before choosing what to plant. Here, a small patch of strawberries are part of the landscaping plan for the traffic island.

One potential concern for guerilla gardeners: the safety of eating plants grown near heavily trafficked roads, due to the potential for consuming plants contaminated by car fluid runoff. Additionally, plants grown in proximity to pollution or toxins tend to absorb the toxins in their roots.

Guerilla gardening began in the 1970s by New York City's Green Guerilla Group. They transformed a neglected lot into a beautiful garden; the space - on run-down Bowery St. - is continues to be maintained by volunteers.

Here, sunflowers add a splash of color to London streets.

One of the largest guerilla gardening initiatives took place in Copenhagen, Denmark, in 1996. Have på en nat ("Garden in a night") involved more than 1,000 people transforming a tract of abandoned land into a garden in a single night.

Here, guerilla gardeners planted sweet pea and then erected a trellis to help keep the plants growing in a neat and orderly fashion.