You asked about the use of turf and sod. I reviewed the use of turf defined as
grass and the surface layer of earth held together by its roots
Some of the questions and answers worked well if you substituted lawn for turf. The rest of them, many from users in Europe, used turf as a synonym for sod. So it seems that turf is used as a synonym for sod and lawn.
I have gone through and retagged some of the 48 turf entries as sod and then merged turf with lawn and made it a synonym of lawn.
I suggest defining these three overlapping terms along the lines of
lawn as grass or groundcover that is already growing on the ground
turf is a synonym for lawn so no definition is required
sod as grass in rolls which must be laid on the ground to grow
updating post history, 40 rows affected (pipe delimited)
updating posts, 37 rows affected (pipe delimited)
updating PostTags associations, 18 rows affected
destroying 'turf': [turf] removed from (0 post, 0 history, 1 tag)
total: 1 tags deleted, 0 posts modified, 0 post histories modified
0 history records had empty tags; retagged to [untagged]
0 post records had empty tags; retagged to [untagged]
updating count for target tag, new count: 592
tag remapping of [lawn] and [turf] complete!
remapping 0 synonyms
1 favorite and ignored tags remapped!
0 tracked tag badges were remapped!
Tag Synonym turf -> lawn was approved!