Hypertufa planters make fascinating and utilitarian garden accents. These lightweight earthy vessels look like stone, are ideal for alpine plants, and evoke a sense of rusticity and mystery. If you like making mud pies or building sand castles on the beach, you’ll enjoy making your own hypertufa planter. The recipe and directions that follow will yield a planter approximately 10" × 15" × 7" (25cm × 38cm × 18cm) deep, with 2" (5cm) thick walls.

Note: This project can be messy, so it is best to do this outdoors.

Tool Requirement

• wheelbarrow or large utility tub
• mini shovel or spade
• gloves (elbow-length mucking gloves are ideal)
• dust mask
• mold (old container, pot, pail)
• plastic liner, sheeting or bag
• a sturdy base slightly larger than your mold
• three to four 1/4" to 1/2" (6mm to 13mm) dia. dowels or branches, about 5" (13cm) long
• a depth gauge: a length of coat hanger wire with a piece of tape wrapped 2" (5cm) from one end will do the trick
• a stiff brush or a mill file
  
  

Material Requirement

• 10 Imperial quarts (11 litres) Portland cement
• 15.4 Imperial quarts (17 litres) peat moss
• 15.4 Imperial quarts (17 litres) per lite or vermiculite
• about 3.4 U.S. gallons (13 litres) of water

You can use just about any container of any size and shape for use as a mold for making a hypertufa planter. You can also make inexpensive forms from recycled lumber. If you would like a planter with smooth outer walls, line the inside of your mold with plastic sheeting, as this will make it easier to release the planter after it has cured. For a rustic-looking planter, line the outside of the container. Cover your base with plastic sheeting, then set your mold on it (right-side up if you have lined the inside of your mold, or upside down if you have lined the outside). 

Combine the dry ingredients in a wheelbarrow or utility tub. Gradually add water, using a mini shovel or gloved hands to mix the batch until it can be shaped into a ball when squeezed. 

Pack handfuls of the mix onto the mold, starting from the bottom and working up the sides. To ensure that you are maintaining a uniform thickness of 2" (5cm) as you cover your mold, insert your depth gauge into the mix from time to time, then pat the hole closed. Make drainage holes by poking three to four dowels into what will be the base of the planter. 

Place the planter in a cool shady area and let dry for four to five days, periodically twisting the dowels to prevent them from sticking, and misting the planter with water at least once a day to slow the drying process and ensure even curing. After the exposed surface has dried, remove the dowels and release the form from the mold. Turn the planter to expose the other face, and let dry for another four to five days, misting as before. Once the planter has cured, remove any loose bits or sharp edges with a file or a stiff brush, then pot up with your favorite alpine plants and a suitable planting mix.

L.T.

A Venerable Stone

Tufa (pronounced "too-fah") stone is a generic name used to describe both volcanic rock and tufaceous limestone that contains bits of mica, moss, leaves, and twigs. This versatile rock has played a significant role in agriculture and construction. 

The world's finest olive and citrus groves, as well as vineyards from Napa Valley in California to Tuscany in Italy, are established on tufa soil derived from material ejected from volcanoes. Volcanic tufa soil is essentially nutrient poor and alkaline, yet it is especially favorable for growing such grapes as chardonnay, sauvignon blanc and pinot noir. The soil imparts wonderful acidity to the grapes, which in turn produce mouth-watering wines. 

The benefit of tufa soil in hot climates is its porosity; it acts hydrologically like a sponge or wick, pulling available moisture out early in the season and releasing it back over the summer months. 

Many of the medieval castles in France's Loire Valley, including the enchanted Ussé castle (the one said to have inspired the setting of Charles Perrault's "Sleeping Beauty"), are built from tufaceous limestone carved out of cliffs or dug underground. The constant humidity and temperature in the resulting caves provide an optimal environment for growing mushrooms and storing wine. 

Large tufa stones were also carved into livestock watering troughs. Troughs carved out of volcanic rock were lightweight, while the ones carved out of tufaceous limestone were heavy. Over the years, British gardeners discovered these troughs made perfect planters for growing assorted lime-loving alpine plants that have low nutrient and low water requirements.

Today, troughs made from hypertufa, a mixture of Portland cement, peat moss and vermiculite, make comparable, lightweight alternatives for selfcontained rock gardens.

J.C.L.