What Is the Best Way to Make Faux Rocks?

Structure

• Build an armature, meaning a skeletal structure around which the rock will be formed. This can be made from a cardboard box or from stiff wire, and it will require some creativity on your part. To make the basic shape out of a cardboard box, try cutting out pieces from the side of the box, and reglue the pieces to the exterior of the box at 90-degree angles, so that the pieces stick out from the box and disguise its original shape. Fill in the spaces between cardboard pieces with newspaper, and cover with chicken wire. This step is the same regardless of whether you're making a prop rock or a rock for the garden.

Garden Rocks: Cement Mixture

• In a plastic bucket, mix cement to place over your armature. The mixture should be: one part premixed portland cement/concrete mixture, one part perlite or vermiculite and one part peat moss. Mix together the dry ingredients, and then add water slowly. The amount of water necessary will depend on the humidity and the moisture content of the peat moss. The entire mixture should be cohesive enough that it will stick to the armature. Try to create a mixture that is the consistency of cottage cheese. Wait 10 minutes for the chemical reaction to take place, and apply the cement to your armature using a trowel. Shape the mixture on the armature into the form you wish to make.

Garden Rocks: Curing Process

• Allow the cement mixture to cure very slowly in a garbage bag, misting the rock occasionally. Allow it to cure for one month before removing the rock. Soak the rock in water for three days after allowing it to cure, replacing the water frequently, to leach the lime from the rock. Seal the concrete, and it is ready to use in your garden.

Prop Rocks: Papier Mache

• Mix one part flour to one part water in a bowl. Dip strips of paper into the flour mixture, and then begin draping them over the armature. Cover the armature to make the shape you desire, and allow it to dry. Paint over the papier mache with a light gray paint. Apply darker gray into the indentations to make them more realistic.