How to Build Low Cost Earthen Arbors for your Garden

Many earth artists sculpt earth-clay in fine detail.

Using earth as a building material is popular with green builders because of its low cost, the ease of finding materials and the recycled elements it incorporates. Adding an earthen arbor to your garden provides an opportunity to release your artistic side--it's easy to sculpt and form while you are constructing it. It's also easy to involve children in the project, who learn important green principles that will drive the future of the alternative building community.

Things You'll Need

• Three similarly sized broken cement blocks or flat sided rocks, one to one and half feet sq.
• Source of soil with a clay and sand content
• Bag of wheat flour
• Linseed or other oil
• Melted candle wax
• Carving tools
• PVC pipe, or limber sapling such as bambo or willow, approximately six to eight feet long
• Eight by ten plastic or canvas mixing tarp
• Five gallon bucket
• Five packed buckets of chopped or short straw
• Water
• Application brushes

Instructions

1. 

   Arbor arches can have many configurations.

   Stack your rocks or broken cement blocks one on top of the other until they are one to two feet high, depending on the local amount of rainfall. More rainfall requires a higher foundation to keep the pillar dry from downpour splashing. Arrange your blocks or rocks so the best side is visible. Line them up carefully. There should be a stacked foundation for every pillar you plan to build. If you are making an arbor to stand under, be sure your pillars rise over five feet. Depending on the design, a PVC pipe, willow sapling or bamboo length will arch over to its matching counterpart.

2. 

   Sculpted clay makes great conversation art.

   Dump two buckets of your soil onto the middle of your mixing tarp. Take a big handful of your short or chopped straw and sprinkle the straw into the dirt as you stomp, twist and mix this earth with your feet. Add water while doing this. Wear old shoes, tennies or boots.

   Continue to mix, stomp and twist while adding water. Fold the mix into the center by pulling the tarp edges and folding into the middle. Again, jump, stomp, twist and mix with the feet.

   When it begins to look like a firmly folded burrito, you are almost finished. Firm earth clay kneads like flour dough and looks and feels like finished dough ready to bake. Clay molecules bond to the sand in the mix for a rock solid drying effect. Take the dough-like mix and plop it onto your foundation.

3. 

   Carve and plaster the clay images.

   As the mix is formed upward from the base, be sure to overlap the foundation with the bottom trunk of the pillar, so no water can seep under or between the rock/cement block base and earth pillar. This overlap also helps the pillar hold firm to the base. Work the dough slowly with hands and fingers while forming the pillar. When the mix begins to dry and has a leather-like consistency, begin carving designs onto the sides with the carving tools while working upward in height. Form the pillar into your desired shape--square or round.

4. At the top of the pillar sink your willow sapling, PVC pipe or bamboo length about 6 inches into the top of the pillar, and arch it over to its mate, sinking this into the top on the other side. The lengths are determined by your arbor design. Be sure the saplings are fresh so arching is easy and no breakage occurs. PVC pipe also works very well. Plant your climbing vines at the base of the stone or cement pillar foundations.

5. 

   Adobe walls are thick.

   To seal the pillar surfaces and protect them from rain and weather wear, bring two gallons of water to a boil, and slowly add the wheat flour while stirring constantly. As you add flour and stir, watch for a consistency of cake batter. If you have concerns about tough weather exteriors, add Elmer's glue to harden the paint. Linseed oil with melted candle wax also adds protection. Apply with brushes while still warm for ease of application. Another option is to paint the pillars with water colors, then cover with the oil/wax mix when it is dry.

Tips & Warnings

• Most soils already have a clay and/or sand content. Earth mixing can be labor intensive, and having kids help can be fun.

• Be sure you know where you will obtain your dirt; plan a pond, or find a neighborhood digging site.

References

• housealive: House Alive!
• innerexplorations:Cob Cottage Company

Resources

• The Hand Sculpted House: by Ianto Evans and Linda Smiley