i want to start 3 (maybe 4) new flowers beds this year, around new construction. one about 30 feet long, 3 ft. deep, and one on either side of the front gate in kind of L-shapes, around 3ft in the short length, 6 ft on the long side and 3 ft deep. they will be filled with amended top soil then primarily planted in old fashioned types of flowers and native plants such as bee balm, butterfly bush, lilac, rose of sharon, zinnias, hollyhocks, etc. these are things i see growing around old homesteads all over the place, i assume because they are easy to share. other than landscape timbers what would be an *economical* way to edge them? landscape timbers leach too many chemicals. the blocks they sell at lowes are too expensive for the amount i want to do. any and all suggestions appreciated!