Ollas are a garden irrigation technique that I thought I’d finally try. The method dates back more than 2,000 years with evidence of their use in cultures worldwide—China to North Africa, the Mediterranean to Mesoamerica. The technique was especially useful in arid regions of Spain and Latin America; in fact, “olla” is the Spanish word for “pot.”

The concept is simple: bury an unglazed clay pot in the soil up to its rim and fill with water. The water will slowly seep through the porous clay walls as the surrounding soil dries. They way moisture is delivered directly to the plants’ roots. With no irrigation from overhead, this system reduces water waste from evaporation and runoff. At the same time, plant roots are encouraged to grow deeper and ultimately healthier.

After hearing about them for years, I finally decided to see whether they would work in my own raised beds.

Creating My Own Ollas

I had first seen ollas at a trade show for garden center owners about a dozen years ago. A company was offering these urn-shaped vessels that looked like something an archaeologist had spent a few months unearthing. Beautiful and large—but way too expensive. But the concept has stayed with me, and I’ve always wanted to explore their use. Especially so because my schedule often requires me to be away from my garden for periods during the heat of summer.

Perusing around on Instagram this summer I saw a video of a homemade olla using unglazed terra cot pots. The person had used two pots, sealed their rims together to create a jug shape, and closed up one of the pot bottom drainage holes with a cork. She then buried them within her raised bed with the top (which is actually the top pot’s bottom) sticking just a bit above the surface. She would add water to the pot through that hole.

“That doesn’t look too hard,” I thought. And I thought I could make it even easier by using just one terra cotta pot and placing its corresponding terra cotta saucer on top.

My Olla Method

I purchased several 6-in. diameter terra cotta pots with their saucers for use in my raised beds. Truthfully the hardest part about the whole process was whittling the corks to fit into the bottom drainage hole. Their saucers fit snuggly on top of the open pots, and that help keeps leaves and soil from mucking up the water inside. BONUS – I fill the shallow saucers with water, too, because I hear it’s good to keep water around for visiting pollinators.

Once my DIY ollas had been in the garden for several weeks, I evaluated how well they actually worked. In my next post, I’ll share what I observed—including one surprising result.