I'll use the bigger ones to make the plum tree bed a bit higher. it's a bit low at the moment.

This pic is from last year.
I don't know what we'll do with the smaller ones yet, but I'm sure I can think of something. They are quite pretty. One idea would be to make stone pots, put a plastic pot on the inside, and make a larger shape from chicken wire on the outside and fill the space in between with rocks. The rocks are mostly round, so you can't really stack them without a lot of concrete or plaster.
This pic is from last year.
I don't know what we'll do with the smaller ones yet, but I'm sure I can think of something. They are quite pretty. One idea would be to make stone pots, put a plastic pot on the inside, and make a larger shape from chicken wire on the outside and fill the space in between with rocks. The rocks are mostly round, so you can't really stack them without a lot of concrete or plaster.