Okay, I'll fess up I have used extras from plant exchanges to beautify and green-up properties that are not under my legal ownership. For instance, if you ride the metro or Marc between Takoma Park and Silver Spring, you may spy a few of my orphan plant groupings out the window along the rail line.
Last year I got a River Birch tree at an Arbor Day event and snuck that into a neighbor's yard. The house was and is vacant -- been sitting for-sale several months now. The current owners never mow, maintain, or visit it -- so I figured they'd never know the difference until the tree is well-established.
Pictured here is a pepper plant of unknown variety that I picked up at a "freebie" table during a garden club meeting in a DC library this spring. It was a scrawny little thing started from seed and just getting its second set of leaves. I had little hope for it. I put this one out at the foot of a traffic light pole. It is a very harsh spot -- exposed to direct wind, vehicle + foot traffic, hardpan clay, and dry as the desert. Even the weeds barely make it in that spot. When I pass by on my way to the Silver Spring metro a few times a week I try to give it a bit of water out of the bottle I always carry in my purse and pull out any errant weed I may see. Other than that, it is pretty well on its own. This is the second crop of peppers on it. The first fruits were picked clean about a month ago -- not sure if by human or animal. Whomever it was had a good meal.
Been doing any guerilla planting of your own? Confessions can be made anonymously by posting a comment here...