If the plant is in a location because humans intended for it to be there, then it is cultivated. If it is in a place humans did not intend for it to be, then it is not cultivated. At this point, I would consider the plant to be “wild” or “feral.” Unless it was dumped with the intention of causing it to spread onto your property, then it exists in a location not intended by humans.
Examples:
“Wild,” in a loose sense:
- Seeds from a plant carried in by trucks or trains establish in an area they are not native.
- A garden plant is dug up by a wild animal and dropped, the plant managing to become established in the area it was dropped.
- Weeds in a greenhouse accidentally transported with other species.
Cultivated:
- Plants in a garden, planted by previous or current owners.
- Planted individuals not cared for in any way, but exist in a location because humans intended for them to be there, such as reforested trees.
- Seeds spread by humans to establish a prairie (the first generation would be cultivated, but resulting generations would not be, as they spread by means not controlled by humans).