Make Your Own Hypertufa Trough

If you long for a rock garden but don’t have the space, or you want a home for some miniature plants that will look out of place in a big garden bed, or you are simply tired of looking at the same old pots, a hypertufa trough is right for you. These strong yet lightweight containers have a rugged, rustic look that complements just about any plant palette. They can be pricey at stores, but fortunately, they’re easy to make. Follow these simple steps to create your own.
 

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Materials
• One 10-pound bag of Portland cement
(available at masonry supply stores)
• One 2-gallon bag of peat moss or coir
(coconut fiber)
• One 10-pound bag of coarse sand
• Water
• Plastic sheeting or newspaper
• Large plastic tub
• Cardboard box (for mold)
• Drinking straw (cut into three pieces)
• Rubber gloves
• Dust mask
• Wire brush
• Potting mix
• Low-growing plants

Method
Find a flat, broad surface in the shade and cover it with plastic or newspaper. In a large plastic tub, mix one part Portland cement, one part coarse sand, and two parts peat moss or coir. (See Photo 1.) For our trough, which was formed around a box that was 5 inches tall by 8½ inches wide by 11¾ inches long, we used approximately 10 cups each of the cement and the sand, and about 20 cups of the peat moss. If your trough is bigger or smaller, adjust the volume of materials accordingly.

Add water and mix well. (See Photo 2.)

Add more peat moss or water as needed until the material has the consistency of cottage cheese. (See Photo 3.) If only a few drops of water run out when you squeeze a handful, it’s the right consistency.

Spread the mixture over your cardboard box. (See Photo 4.)

Continue adding mixture until it is about 2 inches thick all around. Make corners and edges a bit thicker.

Insert three pieces of drinking straw in the center of the trough bottom to create drainage holes. When the material is dry, you’ll remove these straws.

Cover the trough with plastic and let it sit for 36 hours. Then test it. If you can make a scratch mark with your fingernail, it needs to sit longer. If you can’t, it’s ready for the next step.

Tear the cardboard box out of the finished trough. Using a wire brush, smooth the rough edges and corners. Then cover the trough with plastic again and leave it for another three weeks.

Before you plant, fill the trough with water and let the water drain out. This will leach out the alkali that’s in the Portland cement. Repeat this step several times within a 10-day period.

Now you’re ready! Fill your trough with soilless potting mix and add diminutive plants such as chives, baby beets, lettuce, radishes, alpine strawberries, hens and chicks, violets, and other low-growing species.

Elizabeth Noll is managing editor of Gardening How- To. Tracy Walsh is the magazine’s assistant art director. Glen Seibert is owner of GreenMan Projects, a horticultural media production company.


Tips
•There are many different recipes for hypertufa mix. Some call for perlite or vermiculite instead of sand. Others call for synthetic concrete reinforcing fibers. Just be sure not to substitute pre-mixed concrete or mortar for the Portland cement.

•Do this project outside. Wear rubber gloves and a dust mask.

•If you’d like a square or rectangular trough rather than the more casual shape shown here, simply use two cardboard boxes, one bigger than the other. Put the small box inside the large one, and fill the space between (about 2 inches for a medium- sized trough) with the mixture. After the material cures for 36 hours, carefully tear the boxes away.

•Bring hypertufa troughs indoors in winter. They may crack in freezing temperatures.