Old-World Troughs Are A Fun And Inexpensive Winter Project
by Cecile Garrison, UC Master Gardener

Here's a project for container gardeners to fill those winter hours, when there is less to do outside. Make a faux stone trough, and then fill it up with your favorite alpine plants or succulents! It's simple, fun, and results in a creative work of art to keep or give away as a gift!

Stone troughs, also known as tufa pots were used in Europe for hundreds of years as water basins and feed containers for livestock. Since they were made by hand with natural materials found in the landscape, they instantly became rustic and charming. With time wooden containers replaced the heavy, hard to move stone troughs, so they were left in place in the fields and barnyards. Eventually they filled with dirt, debris and drifting seeds, which germinated and filled the troughs with interesting foliage and flowers. Avid collectors of antiquities and/or unique plant containers now search for them.

THE MATERIALS YOU WILL NEED
The basic recipe is three parts each vermiculite and peat moss and two parts Portland cement. Don't get Quikrete, since it has rocks and hardens too fast. It's best to work outside near a water source with a large plastic sheet over your work surface as this can be a messy undertaking. You will also need wooden dowels or twigs for forming drainage holes, a coffee can for measuring, a dust mask, a plastic tub for mixing, rubber gloves, a stiff wire brush, and a form.

Finding the right form is the fun part! I made a charming birdbath on a pedestal with two plastic bowls used as the forms. My turkey-roasting pan made a great oval trough. A tall slim cardboard box is great for succulents with the string of pearls and donkeys tail spilling over the sides. Anything that can support the weight of the cement will do, such as cardboard boxes, plastic pots, tubs, dishpans or styrofoam boxes.

MAKING THE STONE PLANTER BOXES
Step one is to cover your form with plastic wrap or a plastic bag. Place it on a stable, plastic covered surface where it can be left to cure for two to eight weeks, depending on the thickness you apply.

When your form (which now becomes the mold) is prepared, blend the vermiculite and peat moss together, then add the Portland cement and mix again until your dry mixture is smooth. Gradually add water until the mixture has the consistency of moist cottage cheese. This will take practice. If it's too soupy add a little more vermiculite and/or peat moss.

The mixture can be applied with the mold upright or upside down. I prefer completely filling the bowl or box with the mixture then scooping out the middle until I have the look I want. Or, you could place your mold upside down then apply the mixture two to three inches thick starting with the sides and working your way to the top. In this instance, flatten the top, which will end up being the bottom of your container. Place wooden dowels or twigs to form drainage holes.

THE CURING PROCESS
Cover your trough with plastic and allow it to dry slowly. The longer it takes to dry the stronger it will be. When the surface is hard enough (you can't dent it by pressing with your finger), carefully remove the mold. This is the crucial phase! One of my pots collapsed completely at this stage, but I had used sand instead of vermiculite on that one. Another pot lost its bottom because the mixture was only an inch thick at that point. I fixed that one by adding three inches of mixture to the inside and letting it dry again.

Roughen up the outside to make it look old. I use a steel wire brush. The trough should be allowed to cure four to six weeks but I have never been able to wait that long before planting.

STONE TROUGHS ARE GREAT FOR SPECIAL PLANTS
Alpine plants and succulents love the quick draining, porous walls of the troughs. They are also perfect containers to confine the invasive mint family. A multi-compartment trough can showcase several different herbs. Specimen plants, which would be lost in the garden, are accentuated in a rustic trough. Try some of the dwarf ornamental grasses or any of your favorite plants.

With a little work and a few simple ingredients you can create new antique troughs, which will bring you the satisfaction of creating a work of art to display your favorite plants

December 12, 2002