Monday, August 2, 2010

Trough Love

Kym Pokorny, garden writer and blogger for The Oregonian, and I were determined to make some hypertufa troughs for our gardens. She wanted one for a sunny area. I wanted one for a part-shade area of my patio. We used the "recipe" given to us by Sedum Chicks, which turned out to be easy:

Hypertufa Trough Recipe:

1 part Portland cement (no substitutes, e.g., do not use quick drying concrete)
1 part peat moss
2 parts perlite

(We used a 1-gallon plastic pot as our standard of measurement, but you can use anything so long as the proportions stay the same. Wear a mask to filter out the fine particles from the cement.) We used a wheelbarrow to mix the ingredients and found that if the light stuff—the peat and perlite—are added first to the wheelbarrow and the cement—the heaviest ingredient—is added last, it is easier to mix. Add water and stir until it has the texture of thick cottage cheese. It needs to be moist enough to hold together but dry enough to create the sides of the trough without slumping. At this point, you can add concrete color agents if you so choose; we left ours the natural gray concrete color because it looks more like basalt, a northwest rock.

We did the final mixing with gloved hands so we could really feel the texture. Be sure to create drainage holes and cover your forms with a heavy plastic so that it’s easy to separate the trough from the form. (Or you can dig a hole in the ground to create a more organic shape.) The texture of this recipe doesn’t allow for embedding mosaic or other decorative pieces, although you could use thin set after the fact to attach the decorative elements.

To make three larger troughs (approximately 2.5 feet by 1.5 feet with 8 inch walls), we used two bags of cement, most of one large bag of peat and most of one large bag of perlite. We had enough left over to cover a small rock to make another small trough.

Cover with plastic to help the troughs dry more slowly and allow to dry for 5-7 days before removing from the form, at which time you can roughen up the edges and exterior to make it look more organic. Kym did wonders for the "aging" of her trough when she used that fork side of a hammer to gouge indentations and hack away smooth edges. If the walls are thick, you don't have to be too gentle. When you have it looking like you want it, let it set another week before planting. The longer concrete sets up, the harder it becomes. The final thing I did before planting the trough was to rinse it with white vinegar, (it neutralizes the lime in the concrete). Rinse well. I used a mixture of cactus soil mix and regular potting soil (about a 2/3 to 1/3 ratio).

For my shade trough I planted (clockwise from the upper right) Hosta 'Green Eyes'; Pinellia cordata, a Jack-in-the-pulpit relative; Aspienium trichonomanes (Maidenhair Spleenwort); Disporum sessile 'Goldbug'; Terra Nova Nurseries’ Ajuga 'Sparkler'; Hackenochloa 'Sunny Delight'; Hosta 'Mouse Ears'; Aspidistra elatior 'Asahi', commonly called Cast Iron Plant, from Cistus Nursery; and Selanginella braunil, a moss-relative that is supposed to turn a pinkish-orange in winter. The Pinellia, Disporum and Selanginella are from Edelweiss Perennials. I bought the Aspienium and 'Sunny Delight' from Out in the Garden Nursery.

I can't wait to see what Kym does with her troughs! If you have photos of a trough you've created, we’d love to see it. Some of the most wonderful troughs I've seen are in the Iseli Nursery display gardens (middle photos). And these cute troughs are for sale at Bauman Farm & Garden, bottom photo.

Fine Gardening also offers trough-making instructions and photos, which you may fine helpful.


  1. The times I've made troughs, we were instructed to turn them out of their plastic-lined forms after 48 hours, and when we left class we were given a zip-lock bag with several cups of dry Portland cement in it. The freshly turned out troughs are still moist on the surface after 48 hours, and rough edges can be filed off, and then dry Portland cement is rubbed with a gloved hand onto the moist top edges and sides of the troughs, into any crevasses left by plastic wrinkles (we were encouraged to wrinkle the lining plastic) making the finished trough look much more like smooth aged cut stone and covering the peat-perlite bits. This gives a much more professional finish to the troughs. I like that the troughs leach lime, and I use the troughs for plants that would prefer a higher pH than my native acidic soil.

  2. What did you use for forms?

  3. I had some Styrofoam forms I saved for just this purpose (a nursery used the forms to ship liners); I'll use them again. For one of the troughs we created for Kym, we used a Rubbermaid container (about 2.5 ft x 1.5 ft with 1.5 ft sides), put the mixture on the bottom being sure to create some drain holes, then centered a small cooler wrapped in plastic in the container to create the shape of the inner area of the trough. We then stuffed the mixture around the sides of the cooler to create the sides of the trough. We did such a good job stuffing the form that when it came time to pull the cooler out, it required a lot of huffing and puffing, some extra water, a crowbar and a few swear words , I'm afraid. (I used this method on my first attempt at trough making and it popped out beautifully so I don't know why it was so difficult this last time. Perhaps because we let them cure longer than I did the first time.)

    A cardboard box would work well, too. Just remember to line it with a heavy plastic or bubblewrap.

  4. Below are two of the troughs I made using the same "recipe" you did. The tile was held by some contact paper which is why the round one is bumpy. I would do that differently in the future! The one with glass tile is a bit better.


    You can view the pics here