It's "guerrilla gardening."
A volunteer told Eyewitness News that no one had done anything to the plot of city property the guerrillas were working on in 15 years.
Tending the piece of city-owned property can be done legally, but these people would rather work for hours on dirt as hard as concrete than negotiate the red tape required to get a permit from the city.
"They give you guidelines you have to follow and you have to fill out a lot of paperwork and do a lot of stuff, and rather than go through that process, it's easier to go out in the community and do it on your own," said "Mr. Stamen."
You might wonder how all these people who didn't know each other before tonight know to show up at this location at this time for a secret dig. Well, guerrilla gardening isn't completely covert anymore, not with Web sites like Twitter, MySpace and Facebook.
"Yeah, the Internet helps do that, but I think it's people in their community wanting to make their community better," said "Mr. Stamen."
Experience is not needed. Many who showed up had no idea what to do with garden tools, but they learn. And not just at night. "Mr. Stamen" and "Roly Poly," the organizers who still like to protect their identity to some degree, have taught gardening at several middle schools and high schools, even taking a day to work with Cassidy pre-schoolers in Santa Monica.
"It shows how you can turn something that is garbage into something that you're really proud of, and that's what they're learning," said Crystal Bilitz, a teacher at Cassidy Preschool.
"There are groups, guerrilla gardening groups, who have a political mission, and they're kind of saying, 'We can do what we want and we don't have to follow the government rules,' but that's not really our goal," said "Roly Poly." "Our goal is to actually beautify cities, so in doing that, reaching out to as many people as we can, makes sense."
The day after a hard night's work you can see the result. As a group, Los Angeles guerrilla gardeners have completed about 11 sites, but by teaching others that guerrilla gardening can be as simple as digging a hole and planting a flower, or by just picking up a piece of garbage, their impact over time will be immeasurable.