Irma,
Don't know what your project is, but have you considered using patio bricks instead.
I found the landscaping timbers just don't last - maybe a year.
With the brick, you can lay them anyway you want - straight, curved, rounded edges and they last forever!
Right now they're $.33 a piece at Lowes.
............cheryl

http://www.lowes.com/pd_123114-215-156309335_0__

Hi Cheryl, thank you for the news on bricks - a good price. (We want the "frame" to show from a distance in our triangle traffic median project, hence using the HD sale timbers.) Irma