Use patches of sod as outdoor art. Measure a section where you would like to place sod down in strips, to add a decorative touch to walkways or dirt sections. Use the sod to make a traditional design or make a pattern with the sod pieces. Leave the sod pieces intact, or rip them in half to make smaller designs or patterns. Purchase enough sod to cover the area you measure.
Use old wood doors or barnyard planks to make outdoor degradable art. Wood that is naturally weathered can add a rustic touch to any outdoor area. Take an old wood door and paint it in sections with a paint brush to give it a multi-colored look in the top section of the door. Follow the natural indentations and grooves in the door. Use an outdoor paint that will last, and also one that is eco-friendly.
Use colors that fade well and look rustic, such as rust reds and dark blues. As paint fades in the elements, it will add to the old charm of the door. Make a small indentation in the ground where dirt is and dig down with a digging tool, so that the door fits firmly into the natural ground. Make sure the door doesn't tip over, or fall out on its own. Use a little concrete to fill in the hole where the door is mounted, to keep the door secure and in place.
Put natural rock formations, and plant flowers around the door, to add to the look of the art. Use small- to medium-sized rocks that are already in your yard, or have a landscaper install bigger boulder type rock formations as part of a design.
Use natural slate and big round rocks for a layered or varied affect. Have a landscape designer work with you, or do this yourself. Paint the rocks with bio-degradable paint for an artistic effect. Painted rocks can add a unique look to an outdoor section as part of a landscape motif.