Do you ever have problems with the spreading of a garden bed? Does it have more to do with you adding more plants to the bed (like in my grass bed), or does it have more to do with the plants themselves propagating and spreading (like my fence bed)?
A lot of the plants in my yard may be considered invasive (like that Asiatic Jasmine and Boston Ivy that the previous owner planted), and some I've planted (like the giant petunia which some call Mexican Petunia, but others have said that it's not, and according to the Botanical Garden of Key West, it's Carolina Petunia), and still others probably should be considered invasive, but because it has a benefit it's generally okay (like passionvine).
I've known for a while that the Asiatic Jasmine and Boston Ivy moved into the neighbor's yard; but I didn't realize that the Petunia and the Passionvine had moved into the other neighbor's yard until I saw it blooming through the fence...so I stuck my phone over the fence and took a photo:
Uh Oh. But also considering they have the hose out there I think they're actively trying to encourage the petunia/passionvine combo.