Comment by sologoub

If you try to make a planting bed in any settlement that’s more than say 100 years old on a site that was continuously lived on, you are guaranteed to come across at least some shards of glass, pots, plates, etc. Even if the spot was never explicitly a trash mound. Things break, people usually try to pick them up and put in trash, but (especially in grass) miss pieces. When kids break stuff you often don’t want them picking up sharp objects. Things get stepped on and pressed into soil. Many many reasons to find pottery shards where they seemingly don’t belong.