Sunday, September 9, 2007


I once saw a Far Side cartoon in which the geeky looking scientist stands before a chalkboard filled with complicated scribbling and equations culminating, at the bottom, with an equal sign and a dollar sign. The punch line of the cartoon is that after years of research Gary the scientist finally proves conclusively that time equals money. (grin) Gary Larson is a trip.

Anyone who has ever gardened knows this to be true. When you admire those picture perfect gardens in the glossy magazines, know that they are the product of one of two things; time or money. (and sometimes both…) You can either spend 60 hours a week pulling weeds, creating paths, watering, fertilizing, propagating and planting seedlings, waiting for them to grow, or else you can spend 60K and hire professional gardeners and buy the largest full grown plants you can find.

I don’t have 60K.

So when I saw these fantastic large terracotta planters and bowls in a local nursery for the low, low price of $200 – $300 a pop, I reigned in my lust and started thinking how to make something similar myself. And the short answer is I still don’t. But…my Internet research did lead me to hypertufa. Google hypertufa and you’ll find a boatload of recipes for creating this strong, yet light weight concrete mixture, which can be carved while still uncured.

A common recipe might be:

2 parts Portland cement
3 parts sifted peat
3 parts perlite

By tinkering with the ingredients and their ratios, you can produce different types of material. The more peat, the more porous and lightweight the product will be. Perlite can create an old, stony looking material. Vermiculite looks smoother. Adding sand increases weight and strength. But no matter which recipe you use, if you unmold your creation after it sets but before it cures (maybe 4 to 8 hours), you can then carve it. With a wire brush, a drill and an old saw you can shape your form.

Here is an early bowl I created. I piled the hypertufa over a plastic bowl covered with a plastic grocery bag. I also made my brother a flat bonsai container, my dad a planter and my mother-in-law a square cover to hide the water pipes in front of her house. The homemade wooden forms I made allowed me to create much more professional looking pieces, and the forms were reusable. I look forward to using hypertufa to make a number of concrete items for ONE ACRE FARM.

You might also want to check out Walter Jeffries’ concrete work at Sugar Mountain Farm or the interesting article on ferro cement at John's Ottermoon.

1 comment:

Walter Jeffries said...

In August we made a bathroom sink using a similar technique to your bowl trick. Instead of a bowl for the shape we used a child's ball with a smooth surface inside a foam mold. it came out great.