It’s not a new phenomenon. Back in the 1970s, New York City community activist Liz Christy and her fellow “Green Guerillas” planted window boxes and filled vacant lots to start a community garden. Across the pond, Richard Reynolds, a London bloke with a penchant for “illicit cultivation,” has been doing it in his hometown for six years. And even in D.C., local residents, like Marcus Popetz, have been beautifying neglected pieces of unused land before the trend was even popular (or, at least, covered in The New York Times Magazine.)

With the advent of April showers bringing May flowers, news of guerilla gardening is once again popping up in the District.

This month, a group known as the D.C. Guerilla Gardeners, launched a new blog to document their subversive green-thumbing, with their first organized event on T Street NW and Vermont Avenue NW this past Sunday. Theresa Blaner, the founder of the community group, says, “It doesn’t really make sense, it’s kind of an oxymoron: rebellious gardening. Who’d a thought?”

Despite its incendiary-sounding “sneak attacks,” the D.C. Guerilla Gardeners are pretty tame, planting flowers like Evening Primrose and Black-eyed Susan.

Meanwhile, back in England, Reynolds has launched a new campaign, known as Pimp Your Pavement (the guerilla gardener’s version of Pimp My Ride?), to invite local authorities to participate in his movement to reclaim abandoned flower beds, neglected traffic islands and tree pits.The London Sustainable Development Commission, London Festival of Architecture 2010, and The Conservation Foundation have all signed on to get involved.

Other cities are getting in on it, too. Gardeners in Glasgow, Scotland are planting raised flower beds in local meadows. Urban farmers are growing vegetable patches in backyards across Austin, Texas. And a pair of enterprising designers in Los Angeles are distributing vending machines for “seed bombs” -a  mixture of clay, compost, and seeds.