How to Make Faux Boulders

Real rocks can be beautiful but they're heavy. For many landscaping projects, it's preferable to have a lightweight, rock-like object that is easily transportable. Making faux rocks for placement in your garden or around your pond means that you can make the exact size and shape rock you want, in the color that looks best in the setting. Your imagination and artistic skills are the only limits in creating artificial rocks -- and they're usually a great deal less expensive than the real thing.

Things You'll Need

• Block of foam rubber
• Scissors
• Sharp knife
• Chicken wire mesh
• Metal snips
• Pliers
• Newspaper
• Bucket
• Concrete
• Concrete coloring
• Trowel
• Spray bottle
• Sheet of plastic

Instructions

1. Shape the block of foam rubber with your scissors and knife to resemble the general shape of the rock you have in mind. Do not worry about the precise shape at this point; just get it close.

2. Cut a piece of chicken wire big enough to fit over the foam rubber, using your metal snips.

3. Bend and shape the chicken wire to fit around the foam rubber, into the approximate shape you want your final rock to be. Fill any gaps between the foam rubber and the chicken wire with crumpled newspaper. Bend and connect the ends of the chicken wire together with pliers.

4. Mix a bag of concrete in a plastic bucket, following the package directions. Add cement color until you achieve the color you want for your rock. Most colors dry slightly lighter than they appear initially.

5. Cover the bottom of your chicken-wire boulder with concrete, using a trowel. Trowel on a relatively thin coating of concrete, no more than 1/2- to 3/4-inch thick. Allow this initial coating to set for 20 minutes.

6. Turn the boulder so the coated side is on the bottom. Coat coat the top of the mesh with layer of concrete 1/2- to 3/4-inch thick. Let this coating dry for 20 minutes.

7. Coat the rock with a second layer of concrete -- this where your full artistic skills come into play. Shape the concrete into the look you want for the finished rock. Don't worry about the underside of the rock.

8. Dry the rock -- this is a vital step. Moisten the boulder with water from a spray bottle, then drape a plastic sheet over it. Do not set the rock in direct sunlight. Spray it with water at least twice a day. Keep it under the plastic sheet for seven to 10 days, the minimum time it takes concrete to cure properly.

9. Set the boulder in place in your landscape. It's OK if the boulder gets wet, and plants can be allowed to grow on and around it, just as if it were a real rock.

Tips & Warnings

• Practically anything that is lightweight and approximately the size and shape you are looking for can be used as the core of your boulder.

• Do not try to speed up the curing time for the concrete.

Resources

• Artifical Rock: How to Make Hollow Artificial Rock