Many years ago, I purchased creeping jenny to add to my outdoor flower containers. Creeping jenny is labelled as an annual, and who would not believe a plant tag? At the end of the season, I dumped the containers into my vegetable beds. The next spring, I was surprised to find that the creeping jenny that had spent all winter with its roots in the air was still alive.
Foolishly, I thought this would be a great plant for my garden, so I dug up and planted bits all over. The plants flourished so well, that they took over the flower beds, filled up every bit of open space, and got into the lawn as well. They root from every node, which means every inch or so. They break when you pull them, and every bit of root that stays in the soil will start a new plant.
It is important to put the pulled plants in a plastic bag and in the garbage, not the compost, where they will happily re-root and continue their thuggish ways.
They are lovely in early summer, with bright yellow-green leaves that contrast with everything else. But by mid summer they become crispy and ugly, but are still almost impossible to remove completely. Herbicides don't really work - you need to be careful not to apply so much that you kill the top growth before the chemical reaches the roots. Nothing but repeated digging gets them. They can even survive weeks covered with a tarp, getting no light.
I still try to get them out, but they have overtaken a few of my beds, winding around perennials and covering the ground with their leaves. In one area beside the vegetable beds, I pulled out as many as I could find, and then covered the area with plastic and then pine needles for a year. The fight continues!