Many cities in the world are benefiting from the night activities of a group of people who call themselves guerrilla   gardeners. Armed with trowels, spades and a van full of flowers and plants, guerrilla gardeners turn abandoned urban land into a blaze of color. In city centre locations where there was mud, weeds and empty plastic bottles, residents often wake up to find that the wasted area has been transformed overnight with brightly-colored bedding plants. In most British cities, local governments and police turn a blind eye to the effort of the gardeners, whose activities are always carried out under cover of nightfall. And so far, there has been nothing but praise from the astonished and delighted local residents when they find their neighborhood transformed in such a striking fashion. Not only do the guerrilla gardeners beautify neglected places, they also return regularly to water the plants and weed the flower beds. They also make sure that at least some of the plants they bring are evergreens, which means that the area doesn't look depressing in the winter months. The first guerrilla gardener in London was Richard Reynolds, whose day job is at an advertising agency. Mr. Reynolds, a graduate of Oxford University, began his efforts two years ago when he moved to a flat in a tower block in South London. From his balcony, he could see several empty concrete pots, placed by the local governments to contain plants but never used. He went out after midnight and filled the pots with plants, and then planted more flowers in the path leading to the entrance to the block. He then set up a website to explain his plan and called upon more gardeners to join him. Cash donations flooded in and, more importantly, volunteers rushed to be part of the campaign. Within six months, there were five hundred people in London prepared to come out at very short notice to restore neglected parts of the urban landscape. There are now unofficial but carefully-organized groups in many cities in Britain and North America and there is also a website where would-be urban gardeners can find out the location of the next expedition. These guerrilla gardeners do their work   _  .
at the request of the government nearby their house often in return for others' help out of their own free will