Hello again.
Sorry for the takeing so long...
I did search and found the mod. It's a script mod. I'm a little "afraid" of those but okey. What patch level is required to use it?
Modhunter,
There's another non-mod solution if you're playing a save where using base game cheats won't be a problem.
Here are the steps:
1. Open the cheat console (Ctrl+Shift+C), then type in testingcheats on
2. Have you sim walk over to the trash plant and shift/right-click on the plant then choose Set as Head.
That plant has now moved onto your sim's head.
3. have your sim walk anywhere well inside their home lot, then shift/right-click again on the plant on your sim's head to choose Reset Object.
This should move the plant from your sim's head to the ground within your sim's editable home lot.
4. Now you should be able to delete the offending plant because it's on your lot.
Sorry, I didn't post this sooner but I typed the above steps from memory.
I thought I would test the process before posting but keep getting distracted.