Gardening techniques for water conservation

I intended to publish this quite a while ago, but wanted to have a picture of my own ollas (discussed below). But, they’re taking longer than expected, and anyway they’re ugly. You can see much prettier ones elsewhere!

As I detailed recently, I am a big proponent of gardening as a way to increase self-sufficiency and reduce dependence on unsustainable, nonlocal food production systems. Continuing in that mode, I wanted to share two gardening techniques invented by the Native peoples of the southwest which can help conserve water.

I’ve been very interested in applying permaculture, but haven’t been able to find much information on desert permaculture. These two techniques are a good place to start for those interested in creating a sustainable desert garden. After all, indigenous peoples managed to do it for thousands of years–so it is possible. It’s just high time we started learning from them instead of trying to reinvent the wheel as if we were living on the Mid-Atlantic seaboard.

Waffle gardening

Raised beds or boxes are practically de rigeur for modern gardeners. They make sense in rainy climates where too much water could rot plants’ roots. But that is not a problem in the southwest. Instead, it makes a lot more sense to use sunken beds here.

The Zuni people invented a method of gardening in 2×2-foot or 1×1-foot sunken squares–nowadays called a waffle garden for obvious reasons. The sunken bed helps contain water, preventing waste through runoff. The little walls help protect seedlings from cold and slows evaporation by disturbing wind flow. Each 1×1-foot square can support a corn plant, a bean plant, and a squash. These three are known as the “three sisters” because of their unique interdependence: the cornstalk provides a pole for the beans to climb, the beans accumulate nitrogen in the soil, and the squash leaves provide shade and thus act as green mulch. More importantly from the human perspective, the three vegetables combined provide all the necessary amino acids for the human diet. Sunflowers and lambsquarters are other indigenous crops, in case you’re interested in trying Native methods with Native crops.

Sadly I didn’t learn about this method until after putting in all my plants this year, but I plan to try it next year. Another plot holder in my community garden seems to be giving it a try though.

20150419_174823Your waffle garden beds don’t have to be perfectly regular; the important thing is that they are a few inches deep and that the walls hold water.

More information:


Ollas (from the Spanish for “pot”) are narrow-necked unglazed ceramic vessels which were used for gathering and transporting water and for irrigation by Native southwest peoples. The pot was buried in the garden plot with its mouth above the soil. The vessel was then filled with water, which slowly seeped out to keep the soil moist at the root level. Since the water was contained below ground it prevented evaporation and helped regulate the temperature of the soil, and by keeping the soil surface dry, weeds would not flourish. Interestingly, this brilliant idea seems to have occurred to many farmers around the ancient world, with the earliest instance possibly being north Africa. They are still used in China, India, Iran, Brazil, and Burkina Faso (source).

Ollas made by Cahuilla people.

Ollas made by Cahuilla people.

You can even add fertilizer directly to the olla. It is recommended ollas be refilled when the water level drops to about 50% to prevent the buildup of salts which could impede seepage.

There are a number of online tutorials for DIYing your own ollas, such as this one. You can even decorate your olla lid like this. You can also buy ollas, but they are more spendy than making them yourself by gluing and caulking a couple small terracotta pots together. Two 6-inch pots and two 4-inch trays (the makings of a single olla) cost me $4.20, not counting glue and caulk which will seal more than one olla. So about $4.50 a piece, which is a lot better than the approximately $20 you will pay for a pre-made olla here in the U.S. If you have access to clay and a kiln, you can handbuild ollas (no wheel necessary) like the indigenous peoples of Inland Southern California did.

I have read, though I don’t yet know from experience, that using ollas is twice as effective as drip irrigation and 10 times more than typical surface irrigation. I’m lucky in that I don’t pay for water at my community garden; but saving water is now even more important than saving money. I’m planning on installing four ollas with my native perennial herbs to begin with. Next year I’ll see about branching out to the vegetable section of my garden.

In making my own ollas, I have found the process to be somewhat more complicated than suggested by the various tutorials I consulted. Getting a truly waterproof seal with the caulking is very time-consuming because there are tiny, tiny little gaps. I’ve had to caulk and re-caulk one olla probably four times now, each time discovering new leaky spots. Also, when you DIY an olla using terracotta pots, you won’t be able to see inside to gauge how much water is in there, at least not easily, because the opening is about the size of a quarter and it will be dark inside. So figuring out exactly when the olla needs refilling might take some fiddling. Finally, the water that seeps out of the olla doesn’t travel very far. I gather from the charts in the article linked below that for an olla made with 6-inch diameter pots, the water will extend out about 1.5 inches from the surface of the pot. Your plants’ roots will grow toward (and even eventually surround) your ollas, but they can only go so far, so your ollas need to be fairly close to your plants.

But in spite of these fiddly aspects, I think the potential water savings is well worth a little learning curve. And if your garden is small (i.e., you don’t need a lot of ollas), they are cheap. I was given some extra drip line by fellow gardeners when I started with my plot, but had to buy a bunch more, and now have to buy yet more. I swear there is a mile of drip line crisscrossing my plot. I’m willing to spend on irrigation supplies because they will (fingers crossed) last for years: they’re an investment, and if there’s one thing I’m willing to invest in, it’s food. But I know that for food-gardening to be a realistic proposition for the average American family, it has to be possible without requiring a bundle of capital. Ollas can help make that possible. Another thing I like about them is that whereas drip lines have to be at least partially planned out and laid in advance, it’s relatively easy to add an olla as needed.

More information:


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