All of the houses in our neighbourhood have a "naturally" sloping backyard, which slopes downwards from the house. The spread is about 6-8" over 15-20 feet depending on the yard.
Neighbours on both sides of my house have gravel/interlock, but we have grass. This is a problem as gravel/debris constantly comes into our yard from under the fence. Moreover, I'd like to level our lawn, which means that the soil/grass would eventually be higher than my neighbours towards the back of the yard, and then our soil would spill into their yards.
I looked at a concrete retaining wall but the costs are prohibitive. Are there any other options, preferably DIY, that would help to (1) level our lawn while (2) keeping soil from spilling into my neighbours yards from under the fence?