Planters - Materials?

[Grass roots]

I'd like to build some planter boxes for myself, out in the yard, but I can't afford using expensive materials to do it, like bricks or even 6x6 wood.( those beams cost $20 each! )

Do any of you have some suggestions for inexpensive materials that can be used to build nice outdoor planter boxes, maybe 1-2 feet high off the ground?

[Hound Dog]

You might find some suitable waste materials at construction sites. Check with the building foreman.