Probably pieces to planters. The broken edges are rounded so I'm guessing they have been broken for a decade or two. I've found similar pieces on my property that I know are not from us, I estimate these pieces are around forty to fifty years old.
All are approximate since they are small pieces, and it's really hard to tell exactly from what they came. Terra Cotta has been around since dirt, so it's hard to say whether the first TC is old or new, but the last 2 TC's look modern.
G, what are all the coins? Is that one day's haul for you? WOW, nice finds! Breezie
Your last picture looks like a piece of ridge cap. Ludowici made roof tiles for 130 years. They used square brass nails years ago and copper nails today to hold the roof tiles in place.