hm good picket fence isn’t really cheap either, I think...
Really outrageous, we only have a hedge with mulch at the back, and people regularly drove and parked over it. Then we put up these small 30cm high, 1m long wooden picket fences, but the people (the visitors from across the street) then drove right up to the fence, their car doors open over it, and they trampled through our hedge to get out. wohooo I was so angry.
Currently, lamb’s quarters are overgrowing on the mulch, more than 1m high... now no one gets out there anymore
Maybe you need to put up a dummy camera if the sign alone doesn’t work. Anyone bold enough to let their dog poop in a visible garden probably ignores signs too.