Weathered-looking stone containers from hypertufa -- a blend of cement, peat moss, and sand. Hypertufa containers -- or troughs -- make natural additions to the garden as well as handsome homes for alpine plants on a patio, deck, or balcony. These pots work well for small plants that might otherwise "get lost" in the garden.
- Mold (plastic or metal dishpan, lid, or container; recycled foam ice chest or box liner)
- Portland cement
- Builder's sand
- Peat moss
- Measuring device (1-gallon plastic milk jug with top cut open to make a measuring scoop, or large coffee can)
- 5-gallon bucket with a lid
- Plastic dishpan or similar old, reusable container
- Old tarp, sheets of plastic, plastic garbage bags
- Heavy-duty rubber gloves
- Face mask
- Plastic trowel
- 1/2-inch wooden dowel cut in several 4-inch pieces
- Wire brush
1. Dry mix. Wearing rubber gloves and a face mask to protect yourself from caustic portland cement, premix dry hypertufa ingredients in a 5-gallon bucket. Use a plastic milk jug (cut into a measuring scoop) or coffee can to measure ingredients 1 gallon at a time. Thoroughly mix 1 part portland cement, 1 part sand, and 2 parts peat moss. Scoop out premix as needed for each project; store the remainder in the covered 5-gallon bucket.
2. Add water. Transfer 2 gallons of premix to a plastic dishpan or similar reusable container, and make a well in the center of the mix. Slowly add water, blending it with premix until mixture holds together but isn't sloppy (the consistency of thick mud). If the mixture is crumbly, add water; if sloppy, add dry hypertufa mix. Blend more dry mix if needed; once it's wet, it must be used.
3. Cover mold. If using a reusable mold, firmly press mixture into bottom of mold to form a 2-inch-thick base. Stand one or two dowels (depending on the size of trough) in bottom of container to create drainage holes. (If using a foam ice chest or box liner, see option below.)
4. Smooth. Continue pressing hypertufa mixture up sides of mold until trough is completely shaped (1-1/2 to 2 inches thick). Smooth and shape top edge using a trowel; mist with water to smooth.
Option: If working with a foam mold, press hypertufa on the outside of the mold first. Work up to the top edge, then allow trough to dry by wrapping in plastic and curing for two days at room temperature. After the outside of the trough has dried, unwrap it. Press hypertufa along top edge of trough and 1-2 inches down inside the mold. Smooth and shape top edge; decorate, if desired, as described in step 5. Re-cover with plastic and allow to cure. Finish as in step 6.
5. Decorate. the edge of your trough, if desired, with small shells or stones while the hypertufa is moist. Set the trough on a large sheet of plastic (or a garbage bag), wrap it up, and set it aside to dry for a day or two. The plastic allows the cement to cure properly and the trough to dry without cracking. Then unwrap the trough and remove the reusable mold. Remove dowels from drainage holes.
6. Dry. Scrape and score outside of trough with a wire brush to roughen it and make it look more like stone. Round off top edges and corners, if desired. Allow trough to continue drying and curing for at least 3 weeks outdoors in the elements. Finished hypertufa pieces are heavy as stone but not as heavy as concrete.
Planting a Trough
1. Prepare. Before adding plants, neutralize the portland cement by rinsing the finished trough with 1/2 cup white vinegar in 1/2 gallon water. Allow container to dry.
2. Fill. Place a piece of wire mesh over drain holes to allow water to drain without losing soil and to prevent slugs from creeping into the trough. Make a planting mix that holds moisture and drains well by combining equal parts humus, peat or leaf compost, and sand.
3. Plant the trough with an array of sun-loving alpines or slow-growing plants that have similar needs and are adapted to your climate. Cover the soil with 1/4 inch of pea gravel to help hold in moisture and give the garden a finished look.
4. Maintenance. Set the trough on top of a concrete block, bricks, or hypertufa blocks in a protected place where it receives morning or late-day sun. Water the trough garden regularly (every other day in hot weather) throughout the growing season. Do not allow the garden to dry out. Water it with diluted fertilizer once a month. Over time, troughs develop mossy, weathered-looking character.
5. Aging. You can "age" hypertufa (encourage moss growth) by painting the outside of the trough with yogurt. Keep the trough moist and shaded until moss develops.
Plants for a Trough Garden:
Select from a huge array of compact, low-growing, and dwarf plants including varieties of: