The idea and basic method was first conceived by the Scottish Rock and Alpine Club (SRGC). Since then, they and others have tweaked the process to suit specific needs. This is what we do at the Minnesota Chapter of the North American Rock Garden Society (NARGS).
1. Find an empty styrofoam fish box at your local fish shop, meat market or supermarket. It must be strong. Most ice chests are not made of the right stuff, and may not be as durable.
2. Texture the surface to make it look more like natural rock. Be creative! There is no wrong way here. Be sure to go inside the trough as far down as to be sure that soil will cover non-textured areas. Use a stiff metal brush, your favorite gouging tools, a dremel, etc. Wetting the surface prior to texturing will help reduce the styrofoam beads from clinging everywhere. Make ¾ inch drainage holes in the bottom. A small hole drill works slick, or a doughnut hole cookie cutter.
3. Brush off all loose particles. Take a hot air gun over the surface to slightly melt the styrofoam granules. A hair dryer will NOT work.
4. Paint the surface with masonary paint. Masonry paint is more durable. Make sure you get in all the cracks and crevices you created. Look hard! I’ll bet $100 you missed a few dozen spots! It’s not necessary to paint the bottom.
Using more than one color of paint will make the trough more realistic. Your first coat will be the lightest color. You can buy a different color masonry paint, or mix a small amount of crafter’s acrylic paint or concrete coloring with the original color to change the shade. Drying between coats is not necessary. In fact, blending the colors is much easier with a wet surface. After your first coat, if you want to thin the paint with water before applying, you can.
Be creative here too! Use whatever kind of faux painting method you want: paint brush dabbing, sponging, rolling rags, gentle rubbing, etc. All are useful.
Adding sand to the paint, or throwing sand on the freshly painted trough can produce an interesting effect. But we have found that doing so makes the trough more vulnerable to paint scrapes and other mishaps. The rough surface tends to “grab” as objects accidientally brush the painted trough.
5. You could also make styrofoam feet for your styrofoam trough. But make sure they cover a large surface area under the trough, rather than just the corners. Styrofoam just isn’t as strong as hyperfufa.
Additions, corrections, questions and queries welcome.
Rick
