If you do not want to spend a lot of money to place natural rocks in your landscape, you can cast fake landscape rocks of any size and shape by using stuff for a lightweight substance which is called hypertufa. You can make custom-made fake rocks for landscaping which are designed particularly for your property with homemade forms and molds and readily available ingredients from your local garden center. From the same recipe, you can create weatherproof fake stone planters and sinks.
First of all you have to create a mold for your fake landscaping rocks from a cardboard box, polystyrene ice chest, old cooler or any other container which is large enough in order to enclose the fake rock which has been finished. After that you can stuff the corners by using bunched up aluminum foil, plastic grocery bags or old newspaper. You have to create the shape inside the container irregular like a natural rock.
As the hypertufa mixture is dangerous for your skin, it is better for you to wear heavy-duty rubber gloves.
In this step, you have to blend 3 parts perlite, 3 parts peat moss and 2 parts Portland cement in a wheelbarrow. After that you have to stir them by using a small shovel in order to create a uniform mixture. Add water, stirring between each addition thoroughly. When the mixture reaches the cookie dough, you have to stop adding water.
It is the time for you to pour a 3 or 4-inch layer of hypertufa into the bottom of the mold that will become the top of your fake rock. After that coat the vertical sides of the mold all the way around the inside by using hypertufa to the sides and then mixing it by using the layer which is located on the bottom.
You have to let the hypertufa dry for 24 hours. The mold should be inverted and you have to lift ir off the fake rock. And then you have to take off the plastic sheet. You can smooth out wrinkles from the sharp edges and plastic by using a wire brush. The fake rock should be enclosed in the plastic sheet again and allow it cure outside at least for one month.
The cured fake rock should be removed from the plastic and hose off loose material. The fake rocks for landscaping should be places in your landscape according to your preference.