Plastic sheeting helps to contain the mess. 

To make one small to medium trough you will need about 30 pounds of cement, 1 cubic foot of compressed peat moss and1.5 cubic feet of sand, gravel or perlite. Dividing this into smaller batches makes it easier to mix. 

Using white Portland cement and cement coloring powders controls the trough color. Depending on the color you want to achieve start by adding 1 cup of powder to a batch of hypertufa. 

Adding 1 to 2 cups of acrylic bonding agent, such as Acryl 60 and Embond, to a batch of the hypertufa mixture, when you add the water may make the trough stronger. This agent can also be added to ready-made mortar mix to mend cracks and broken troughs. 

Plastic fibers or fiberglass, such as Hi-Tech Fibers, can be used as a reinforcing material. Use about 1/10 oz per gallon of wet hypertufa. This equals out to putting enough fibers so you see a large number of fibers in the mix. Be sure to add them slowly and a little at a time while mixing to avoid the fibers from balling up. Once the trough is dry, use an open flame such as a butane lighter or soldering torch to singe off the protruding fibers. 

When using rectangular forms, build up the corners a little thicker to allow for strength. For an upside down “bowl” form, cover the form with plastic and evenly apply the mixture over the plastic-covered form. Test the thickness with a nail or wire. Be sure to make what will be the bottom when finished thick and flat enough for the trough to sit level. Cover with plastic sheets when finished. 

Generally, upside-down troughs and small, foam-form troughs are ready after 36-48 hours. Large troughs in foam forms are ready in 24 hours. 

Considering how involved this hypertufa process is, making troughs in the fall or winter will allow enough curing and weathering time before planting. Soaking the trough in a solution of potassium permanganate or a mix of 4 parts water to 1 part muriatic acid can help speed up the process. 

The Internet has several sites on hypertufa. A great resource book which explains the entire process of making and planting in hypertufa troughs can be purchased by check made out to NARGS for $6.50 postpaid. Order from NARGS, PO Box 67, Millwood, NY 10546.