The second, less expensive option is pressure-treated landscape timbers (railroad ties are ideal). Pressure-treated lumber is impregnated with chemicals that make the wood impervious to rot.

Retaining wall blocks create a more formal look, while using railroad ties or landscaping timbers appears more rustic. It might seem as though stacking up landscaping timbers is the simplest do-it ...

Build the garden one “used railroad tie” or three landscape timbers tall. Cement blocks also work well. Fill in the bed with landscape light mixture or a similar soil mix where compost makes ...