Using salvaged items to create and enhance a garden is good for a number of reasons. Salvage is usually free, so if you're on a tight budget, a little creativity can bring great rewards. Reusing items others have thrown out keeps them from clogging up already over-full landfills, and repurposed vintage items can add a certain charm to a garden or outdoor space. Many people find great satisfaction in bringing new life to discarded items.
Wood can be put to use in any number of ways. Shipping pallets make good containers for raised gardens, or you can stand them against the wall and turn them into wall planters. Railroad ties, which are thick and heavy beams of wood, can be used as retaining walls. Resurfaced old wood doors make funky outdoor tables or can be latched together to create temporary walls. Some old wood may have been painted with lead paint, which is poisonous and should be removed before using. Railroad ties are treated with chemicals that should never be near food plants.
Used masonry and rocks can be put to use, too. Rocks and stones can be used to mark pathways and garden borders, or to build walls and decorations. Cinder blocks stacked two high in a square or rectangle make solid raised garden beds. Used more creatively, cinder blocks with holes can be stacked at odd angles to each other and turned into a modern-style planter for succulents. With some weatherproof adhesive, patio blocks can be made into solid and stylish planters.
Metal of all sorts can be put to good use in a garden. Old metal poles can be bent and tied or soldered together to make tomato cages. Old metal fencing, chicken wire, headboards, or anything else fairly tall can be turned into trellises for climbing vines. Old furniture with springs but without fabric or stuffing can be used to help tall flowers stay upright -- just put it over the flower bed and let the flowers grow through it. Make sure any sharp edges are filed away, especially if there are children around.
Sometimes found items don't fall into any particular category, but are useful nonetheless. Intact old windows, for example, make inexpensive tops for mini greenhouses or cold frames. Combining used items can give new life to any number of used materials. Clear plastic sheeting combined with bendable metal rods can be turned into hoop houses. Entire greenhouses can be built with repurposed wood, stone, metal and glass. For the artist, all of these materials can be made into one-of-a-kind garden art.