Old-looking concrete is quickly becoming all the rage in the trendier landscaping circles. Landscape architects such as San Francisco-based Richard William Wogisch see old concrete as an environmental and esthetically-pleasing alternative to new construction. Whatever your uses for old concrete, the good news is that it is relatively easy to make brand new concrete look old--and it takes almost no artistic talent.
Put your concrete piece in a place with good drainage and where it can be reached by a garden hose.
Put on protective clothing, heavy gloves, eye protection and a breathing mask.
Pour a quantity of hydrochloric acid into a glass dish. Do not breathe the fumes even with a breathing mask in place. Use a paint brush to brush the acid onto the concrete.
Allow the acid to sit for 20 to 30 minutes. Hose it off thoroughly with garden hose. Do not get acid/water on your clothing if possible.
Inspect your concrete. If the acid has not etched it sufficiently for your needs, apply a second coat of acid and wash it off thoroughly after 10 minutes.
Thin the rust-colored cement stain (available at most hardware stores) with water. Use a clean paint brush to streak the stain onto your acid-etched concrete in patterns that are pleasing to you. Start with just a light coating and allow to dry before adding additional stain.