Cameras thesedays have what are called "activity zones". The image is broken down into a grid of many squares, and you select squares to ignore if there is any movement so you are not alerted when it happens (e.g. if you have a tree that moves in the wind, or a busy street that people walk along). I bet your neighbor has already de-activated your garden as an activity zone. They would be much more annoyed than you to have a camera alert going off everytime you are in your garden. So rest assured that you are not being recorded (unless you are having a dispute and they are protecting themselves from you).
However, if you are still worried I would suggest growing a clump of 'peppermint stick grass' in front of your fence. Very fast -growing and reaches 12-feet tall. Although you have not said on your profile what zone you are in, I hope it grows in your zone. Also, you did not say whether the location is shady, sunny, part-shade, etc.
https://www.sandysplants.com/i...