How to Construct a Homemade Hypertufa Planter
Patterned after the real stone troughs once used to water livestock in England, the modern-day hypertufa trough is considerably more lightweight and can be fashioned into a variety of shapes, sizes and colors. Due to the durable materials with which they're constructed, these containers are able to withstand the elements and only look better with time. Once you get the hang of constructing these homemade containers, you'll be making them in no time at all.
Materials and Tools:
Mold (can be a saucer)
Planter or box
Plastic wrap (any type of lightweight plastic to line the mold)
Containers to mix ingredients and for measuring
Gloves (rubber or latex)
Face mask for the mouth and nose
Dowel rods, cut into six-inch lengths, for making drainage holes (ordinary 3/4 to one-inch diam. sticks will do)
1/4-inch hardware cloth for screening peat moss
Wire brush to roughen finish on outside of trough
Portland cement, one part
Peat moss, one to one-and-a-half parts
Coarse sand or perlite, one to one-and-a-half parts (Note: Perlite will make the trough lighter in weight, but sand will give it a smoother finish.)
Water, one part
Prepare the Mold
Get the mold ready ahead of time, so all you have to do is dump in the prepared mixture without having to remove your gloves. Apply the plastic wrap on all sides of the mold, including the rim. This provides for easier removal so the mixture won't stick to it.
Combine Dry Ingredients
Place hardware cloth over the mixing container to screen out sticks and other large pieces from the the peat moss. If you desire a more textured look on the outside of the trough, screening is not necessary. Wear gloves when making your trough; the materials are caustic to the skin. To avoid inhaling dust from the dry ingredients, wear mask protection over the mouth and nose. In the mixing container, combine the dry materials — Portland cement, peat moss and sand or perlite.
If the container is to be larger than 18 inches in diameter, fiberglass or micro-synthetic fibers called Fibermesh can be used for added strength. They can purchased at most concrete product suppliers. Simply add a handful (or one part) of the fibers to the dry-ingredient mixture. At this time, you can also add a concrete dye for color. However, these colors tend to fade after being exposed to the sun and rain. If you choose to include a dye, add enough so that the entire mixture is colored.
Moisten the dry ingredients with about one part water. Take care not to make the mixture too soggy.
Mix Wet and Dry Ingredients
The mixture should now be about the texture of thick oatmeal. If it has too much water, simply add more dry ingredients until you've reached the desired consistency. It shouldn't ooze water.
Add Mix to the Mold
Firmly pack the mixture into the mold, building from the bottom up. Make sure the walls are one to two inches thick on the bottom and sides.
Pack the Mixture Into the Mold
When adding the mixture to the walls of the mold, continue to pack it firmly. Keep in mind that the rim of the trough will be visible. Begin to smooth it as you're finishing the sides. You can finetune the finish with a wire brush after the trough is removed from the mold.
Insert Dowels for Drainage
If the container is to be used as a planter, insert wooden dowels into the bottom for drainage holes and press firmly. If you skip this part, you can drill holes into the bottom of the planter later, using a ceramic drill bit. Place the trough in a sheltered place for about 48 hours before unmolding. Cover with plastic to retain moisture. The more slowly the concrete hardens, the stronger the finished trough will be.
Add Decorative Materials
Carve out a textured rim (as shown to the right) or inlay decorative elements, like rocks or seashells collected during your travels, colored tiles or whimsical sculpture, to add interest to your container. Add the objects as you pack the mixture into the mold. Avoid using objects with smooth surfaces, such as marbles, because they have a tendency to break loose.
You can also add deeply-veined leaves, like elephant ears or hollyhock, for texture on the outer surface of the trough. Before adding the mixture to the mold, simply add a few leaves with the backsides positioned away from the mold and firmly press in place as the mixture is gradually added. When removing the trough from the mold, peel the plastic wrap and leaves away from the outer surface. Use tweezers to pluck out any lingering material.
Remove From the Mold
After the inital 48-hour set-up time has passed, carefully separate the trough from the mold. Remove the plastic liner and dowels.
Use Wire Brush for Finishing
While it's still in the early stages of drying, your trough should be given its finished look. Use a wire brush to smooth the trough's edges and exterior to the desired texture. Note: If you used micro-synthetic fibers in the mix, and you see some of them protruding from the trough after it's removed from the mold, use a propane torch to burn the excess fibers away.
Leave the uncovered trough outdoors for about four weeks to cure. The length of curing time depends on the size of the trough. During this time, it's best to expose it to the elements. Rain can do the work to give your trough a natural, weathered and aged look. This allows excess lime to leach out of the concrete. To age more quickly, douse the outside with manure tea, diluted buttermilk or yogurt.
Ready to Plant
Once your trough has fully cured, you are ready for planting. First, place a small piece of screen or pantyhose over the drainage holes to keep soil from washing away.
Because they're porous and typically shallow (although they don't have to be), the plants that do best (with minimum upkeep from you) are drought-tolerant alpines, sedums, herbs, cacti and other succulents. But you can plant virtually anything in your trough; just remember to keep it well watered. There's a limited amount of soil and growing space, so go for plants that are naturally slow growing or that stay petite.
During the winter, don't leave your trough on the ground in climates with freezing temperatures. Moisture can enter the porous openings and potentially cause the container to crack and break during a freeze. Instead, place it on a concrete or other solid surface or bring it indoors into a garage or basement. Because hypertufa pots are made from durable materials, you're less likely to have breakage during a cold snap than you would with terra-cotta pots. Using the micro-synthetic fibers or Fibermesh in the construction of your trough will also help to reinforce the structure for overwintering.