Freeguy posted:To me, the sense of the construction suggests that it is indeed restrictive, because the pertinent (or restrictive) trait of the neighbor, which merits his mention, is that he maintains an impeccable lawn. The commas are included in error. Am I right?
In context you've provided, it makes sense that the relative clause is nonrestrictive. The purpose of the sentence is to illustrate the point made in the previous sentence, that homeowners in the suburbs take their lawns seriously.
What shows that this neighbor of the author's takes his lawn seriously? Is it the fact that he maintains an impeccable bed of grass in his backyard, or the fact that he had his soil analyzed to help him attain optimal growing conditions?
Both facts could be used to illustrate the point, actually. But of the two facts, the latter illustrates the point better. Not many homeowners who wish to have nice lawns go to the extent of having their soil analyzed.
Given that the soil analysis is the main point of the illustrative sentence, the neighbor's maintenance of an impeccable bed of grass is parenthetical. It is material in the background, and the nonrestrictive relative clause backgrounds it.
The only thing I'd change is "a neighbor." I'd say "a neighbor of mine" instead.